MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG TD TF 1500 - Engine Cutting Out

Time for a new thread. This is really "phase 2" of "needles won't insert to shoulders" but I think that one is settled. I realize archives are chock full of "dirty plug stories" but I've tried everything I can find there on the subject to no avail. So here goes...

BACKGROUND: 50 TD just rebuilt both carbs with lean AP needles for life at 9,600'. Checked points, rotor, plug leads, look OK. Attempted to adjust timing a little (wouldn't even start - back to original). Verified all 4 plugs getting spark (by removing plug cap with eng. running - fun!) Jets now at 6 flats out but it doesn't seem to make any difference where I put them. Plugs continually foul!

SYMPTOMS: Starts easily. Idles good and even. But engine cuts out between about 2-3000rpm VERY VERY BADILY!! Runs somewhat smoother above 3,000 rpm but still not correctly. Plugs get completly fouled with dry black soot minutes after a cleaning (see photo att.)

Any ideas would be greatfully appreciated!!
Ed Haskell
CO, USA



efh Ed

How did it run before the carb changes? Ignition problems are frequently blamed on the carbs. Change the rotor first if not already done. Check that the tach drive or cable isn't flipping around and shorting the terminal nut on the distributor. Make sure the coil wire is not pulled loose and/or burned off in the center of the cap or the coil. I would change points, condensor, and the coil. I think the plugs would look like that if the ignition was faulty also. My TD would run fairly well at speed with teh choke fully out- it just wouldn't idle- so I'm suspicious that running a little rich would foul plugs. What heat range plug are you running? George
George Butz

What are you using for plug wires?
(Try search of archives for "Lucas Bumble Bee") I would be highly suspicious of low spark due to not so good wires.
David 55 TF1500 #7427
David Sheward

Ed, change the condenser - a very probable cause of your problem.
Baz
Baz

Ed,

Disclaimer: I am not in the top 100 on this BBS when it comes to MG tech expertise, but here goes...

This summer my plugs looked just like yours, and while the TD started easily, on short road tests it ran like crap. Actually, it ran rather well for a car running on only 2 cylinders! The weirdness was that it was not always the same 2 cylinders fouling out!

Please consider the following:

My carbs had been professionally rebuilt, with new shafts, bushings, butterflies, etc., but some 25,000 miles (and fifteen years) ago.

I removed the carb suction chambers and, holding one, inserted each piston and twirled. I had a tight/loose situation. Swapping pistons, I got an evenish feel for each. Try this test. Reattach, but not until you are POSITIVE that both jets are centered. Expect deja vu here.

I dismantled and cleaned both carbs, and the teflon (?) seals (per a TSO article), replaced subsequent to that long ago rebuild, were as new, with no leaking. There is BBS archival material on these seals.

Replace your spark plugs with brand new ones! The TD/TF Workshop Manual says set at .020"-.022". John Twist says .035". Deja vu all over again. .030" worked for me. Go figure.

I use Champion L87Y plugs, in a slightly shaved banana head fitted with oversize valves, a banana block overbored to 1466 cc, a Lucas Sports Coil, and a standard Lucas 40162 distributor (rebuilt by, and with advance curve set by Jeff Schlemmer), static timing set to 8 degrees BTDC, with a Crane standard cam, SU pump, and SU 1 1/4" carbs.

I started with the six flats each carb mixture, balanced the air flow with a Uni-Syn (hot), then readjusted the mixtures, using the gunson Color Tune. I then installed new K & N 1 1/4" air filters.

My TD has never run better. It starts instantly in any weather, idles hot at 700 RPM, has great pulling power, with gas mileage close to 30 mpg (93 unleaded).

No opinion on carb dashpot oil... I have used 3-in-1, Castrol 20-50, Redline MT-90, Marvel Mystery Oil... Just have something in there.

I know nothing about carb needles and altitude - can't help you here.

Your 7/16" carb float bowl lever settings (mentioned in your prior post) are 1/16" more than the manual recommendation, but the same as mine. My Grose-Jets have been trouble free.

Good luck! And good running soon!

Cliff
C A Schnell

Ed,

I just read the posts from George B, Dave S, and Baz. Maybe they are on to something.

In 1968, in a book titled "How to Repair Your Foreign Car", author Dick O'Kane entitled Chapter 13: 'Carburetor is a French Word Meaning "Leave It Alone"'. Maybe he was on to something also!

Again, good luck!

Cliff
C A Schnell

Ed - Cliff said "Reattach, but not until you are POSITIVE that both jets are centered." this is a very important test of the carburetors, especially after having had the carburetors apart. Remove the damper from the dash pots and lift the piston in the carburetors about a quarter of an inch, then drop them. They should drop right to the bridge of the carburetor with a clunk. Again raise the piston all the way to the top and again drop it, again it should drop right to the bottom with a clunk. They should not catch or drag at any point on the way down. the other thing that Cliff mentioned was having the correct vacuum chamber together with the proper piston on the correct carburetor - they are not mix and match, they must always be kept together as a set. You should also see that the edge of the piston that fits in the vacuum chamber is clean, dry and free of any burrs, the same thing applies to the inside of the vacuum chamber.
David DuBois

Ed - Cliff said "Reattach, but not until you are POSITIVE that both jets are centered." this is a very important test of the carburetors, especially after having had the carburetors apart. Remove the damper from the dash pots and lift the piston in the carburetors about a quarter of an inch, then drop them. They should drop right to the bridge of the carburetor with a clunk. Again raise the piston all the way to the top and again drop it, again it should drop right to the bottom with a clunk. They should not catch or drag at any point on the way down. the other thing that Cliff mentioned was having the correct vacuum chamber together with the proper piston on the correct carburetor - they are not mix and match, they must always be kept together as a set. You should also see that the edge of the piston that fits in the vacuum chamber is clean, dry and free of any burrs, the same thing applies to the inside of the vacuum chamber.
Cheers - Dave
David DuBois

Ed, along with the other suggestions, if you are only going to tool around the Butte then set your static timing to about 12 to 14 degrees btdc and listen for valve knock. If you plan on driving down to Montrose or my neck of the woods often then set it to about 8 to 10 btdc. If you get down my way I'd be happy to check the carb settings with you.

LaVerne
LED DOWNEY

Hi Ed - sorry you're still getting problems. From the look of your plug, you're clearly running very rich. The end of your last thread went on to carb. settings. Have you made sure fuel levels, sealing washers etc. are OK ? I only ask because you make no mention of sorting out carb. matters. If moving the jet nut up and down has no effect, there is a major problem with the mixture!

A weak spark can also cause plug fouling symptoms and others have referred to possible reasons. A partial breakdown of the coil will let you idle but will misfire at higher revs because the the weak spark has difficulty crossing the plug gap with higher compression. Getting a shock from the leads will still occur! You still need to sort the carbs out first though!

Good luck, John.
J.C Mitchell

An old MG adage, when you think it's the carbs, it's often electrical.
Baz
(change the condencer, it won't hurt)
Baz

Thanks one and all (again),
I will start replacing plug wires, plugs, etc. etc. as various people suggest above and go from there.

Regarding setting timing, several have mentioned "12 to 14 degrees btdc", etc. All I remember from being a stupid kid with a MGB many, many years ago was I hooked up a cheap timing light between the #1 plug lead and the plug and pointed it at the timing mark. Then I fiddled with the distributor until it sounded right and it ran great. How do I go about measuring "12 to 14 degrees" below top dead center? The shop manual isn't very specific - it sez just hook up a "12v light bulb" - oh boy!! It also sez to loosen up the adjusting nut to turn the distrib. That does not work at all!! I must loosen it and the nut that holds it into the chasis to make it turnable! It also sez to turn it till the points are just about to open when timing mark arrow is pointing at notch in pully indicating #1 and #4 are at tdc. I did that and it refused to even start! Hum???
Ed
efh Ed

I'm on my "box" again screaming :
"plug wires" @ the top of my lungs!
Been there done this ...3 sets of replacemrnt wire from Tiwan in a year ...all three were...no nice way to say this....crap!
I have one of those fancy little spark checkers that simulate what you can find out with a good set of insulated plyers!
Started fine, idled fine, high RPM = low spark! It was not the coil, condenser ect...it was cheap plug wires. Get the Lucas Bumble Bee wire and just look at the differance! Install them before you put out the cash for all the more expensive stuff ..(although you can always do what I did and have a nice "spares" kit to keep in the car!...made a lot of friends by letting them borrow these untill they change their wires.)
The BB wires are cheap, and they look nice!
Cheers,
David 55 TF1500 #7427
David Sheward

Ed,
The 12v bulb will give you static timming...an "old school" timming light will have an adjustment for "advance".
Don't be fooled you really don't need a fancy $$$$ digital timming light (I found my "old school" on ebay for about $10.00)
Your going to learn (like most of us have) that after you have set your timming using all the fancey stuff that our little cars have a built in alarm for inproper timming ...the gearshift will rattle going up a slight grade in 4th gear. The neatest thing about these cars is that the factory tool kit realy does have most of what you need to make these cars run correctly!
Including that little ball-pen hammer to get them an occasinal "wack" once you know the right spot!
Cheers,
David
55 TF1500 #7427
David Sheward

ED,

You said "It also sez to turn it till the points are just about to open when timing mark arrow is pointing at notch in pully indicating #1 and #4 are at tdc. I did that and it refused to even start! Hum???"

It should have started,,,,,BUT, If it refused to start, might that mean that even though you have the proper firing order, the point at which the arrow was pointing at the notch, it wasn't # 1 that was lined up to fire ????

SPW
Steve Wincze

ED
If you do wish to check the piston/vacuum chamber, John Twist has a great video on youtube that shows you how and it is only a few minutes long.
tw hager

Gentlemen,

1. Determine the quilty party, Fuel or air?
2. Start and rev engine to produce symptoms - misfire, cut out etc. No result? see #3.
3. Drive car to produce symptoms.

If you can produce the symptoms just by reving the engine with out driving it, the problem is most likely electrical, as ignition probems are not load related. If the problem only shows when you drive it, i.e. putting it under a load, the cause is fuel related.
If it is a ignition problem, check the condensor first. (also make sure your tach gearbox is not shorting your terminal on the side of the dizzy!)
If it is fuel related check, delivery from the pump first and work your way to the carb needle checking evything along the way.

Good Luck!

Ben Travato

Ed,

You've got several issues going on now and all can effect the other. I'd eliminate the electrical first. Make sure the firing system is in good shape.
Plugs, points, condenser, rotor, coil and cap. Close inspection of the cap is in order even if new as they are known to be cracked right out of the box. Plug wires are as Dave has noted also an issue as would the connections to the cap, plugs and coil. Check your engine ground strap as well. How old is the gas in the tank? You can get a degree wheel and tape it to your crank pully to see where 12 to 14 degrees are or just take a rough guess. Quarter of a turn would be 45 degrees. Half of that or an eighth of a turn is 22 1/2, etc. I think you get the idea. The B you set the timing on was marked for dynamic timing. The "T's" are not. Make a little mark on your crank pulley with some white touch up paint or a type writter correction, crayon, chalk etc. It should be to the right side of the notch on the pully if your facing the pully head on. Turn the motor clockwise until your mark lines up with the pointer. The notch on the pully should still be to the left about 10-12 degrees before top dead center. loosen the distributor clamping bolt. Remove the cap. Take your handy $ 1.39 test light and clip to ground and put the probe to one terminal of the coil. If you want you can put a mark on the engine block and distributor to set it back to the same place later. Check to see that the rotor is in the approximate position of the number 1 plug wire pole if the cap was in place. If your light is off turn the distributor in the opposite direction of the rotor movement slowley until the light comes on. Check to see that the rotor still lines up with the number 1 cap position. If the light was on when you started, rotate the distributor in the same direction as the rotor movement until it goes out. Then slowley the other direction until it comes on. Tighten the clamping bolt just enough to keep it from turning on its own. Rotate the engine 360 degrees and you should see the test light illuminate when your mark gets to the pointer. Fire it up and see what she sounds like. Reve it a time or two and if she sounds ok tighten the distributor clamp and give a road test. Be prepared to fine tune the setting to give it the best performance. Then we can go to work on the carbs. This wasn't the TD that was for sale in Salida is it?

LaVerne
LaVerne

Thanks all,
I'm concentrating on electrical first, then back to carbs. Moss doesn't specify exactly what make/part #, etc. for condensor, points, coil and cap. With shipping/handling their prices are a wee bit on the high side. My local Napa had plugs and I bought some new plug wire to make my own leads, but they don't know anything about T's of course. Can someone advise me where to get the other parts and what to buy aside from Moss, including those caps that screw the leads to the dist. cap (some of mine are badly cracked I just dicovered)? Seems like they should be readily available somewhere?

LaVerne, my T came from Arvada area, not Salida. Got it about a month ago. 26k miles since "overhaul" (and a good number of years!) I'm learning....slowly.
efh Ed

Ed, 12 to 14 degrees BTDC (before top dead center) is an advanced value, not what you want for static timing, i.e., engine not running. LaVerne's directions are what you want to follow for a TDC setting that should be a fine starting point. Don't try to do a static 12-14 degree setting. A cheap timing light is all you need to see if your timing is advancing.

If you have a decent relationship with your local NAPA store you may be able to get them to dig up the catalog for early cars and have them locate some parts for you. I have an old Echlin catalog (mine is #104) The Points are Echlin CS201, the rotor is EP41 and the coil is IC64.
Bud Krueger

Lucas discontinued the caps some years ago, as well as pretty much all of the aftermarket suppliers. For some time, it was Moss or nothing. The new caps come with the screw-in terminals and the copper/brass washers. Its not a bad idea to keep a list of things you may need in the future, and then when Moss or Abindgon Spares has a sale, order them and keep on hand. There just isn't very much you can get from the local parts store anymore (a few bearings/seals if you know the numbers, etc.) There are a few other things (as Bud says- if you can find the number), including some Beck-Arley things available locally, but not much. George
George Butz

Bud,

The general rule around here for old school mechanics was to advance your timing 2 degrees for every 1000ft of elevation. Ed being at 9500ft I think the 10 to 12 degree static advance would be a good starting point but definately not something I'd try at sea level. If he is going to be driving down valley a lot then might want to back it down to the 6 to 10 degree range. In any case I'd want to test the performance and definatley be listening for valve knock under load.

LaVerne
LaVerne

LaVerne,
Where is the "engine ground strap" located?
How far to the right of the notch should I put my white mark?
I'm gonna try your static timing instructions tomarrow - too tired now. Gas is new by the way.
Engine cuts out same in garage as on road under load so I do hope it's electrical. I understand your degree thing now I think.
Thanks,
Ed
PS: The car isn't really drivable due to this cutting out problem but we would love to drive it your way some time. Hopfully I can get it there before the snow flies! Do you belong to any local clubs - Gunnison Car Club perhaps? They do some interesting road trips but I'm not able yet.
efh Ed

Wow! 10 degrees static plus about 30 for advance adds up to about 40 BTDC. Without pinging and detonation? Guess we sealevelers (Plymouth, Mass.) play with different tools. I thought the atmospheric difference was an effect for mixture, rather than timing.
Bud Krueger

Bud,
I don't claim to know the physics, but it has aways seemed to help the performance of anything we ran until the mid seventies came along. I'd guess that with less oxygen, lower atmospheric pressure and the need to weaken the mixture causes a longer burn and thus the need to start the fire sooner.

Ed,

The ground strap is attatched to the bell housing bolt near the clutch lever (left hand drive) and the other end to the inside bolt of the bulk head support to the frame. As to a rough guess on the mark without going to the shop I'd say about 3/4" of an inch would be a good start. No local clubs. I suscribe to the "Groucho Therory".... I wouldn't belong to any club that would have me as a member. Actually I joined the Rocky Mountain MGT Registar in September. Being as they are primarily on the front range I don't expect that I'll be an active participant in their events but I do get the news letter and don't feel guilty about having the car club badge on the TF. I can send you a link to their web site if you like.

LaVerne
LED DOWNEY

Disassebly location photo.

LED DOWNEY

Ed:

Form the archives:

"In a recent TSO issue (the NEMGTR magazine), the advanced timing was described as about 1/4-inch BTDC (about 1/4-inch clockwise from the notch on the crankshaft pulley)."

Cheers

Larry
Larry Karpman

Ed, is your car spewing black smoke from the tailpipe?
Tom

No smoke per se, but the exhaust is not what I'ld call "clear". It's sort of "sooty" looking (sort of like the plug picture color), and more noisey than it should be - sort of spitting when you rev it up.
efh Ed

Larry,

If they were advising about a 4 degree advance at sea level I'd guess then 3/4" would give the 12 degree area I'd be looking for at 9500 ft.

LaVerne
LED DOWNEY

I had a similar problem once. The points had lost elasticity, hence the car idles well but gives problems above 2,500 rpm. Check that, change the points.

"Ed, change the condenser - a very probable cause of your problem."

That is probably another excellent advice.

Denis
Denis L Baggi

Ed,
Whilst your in there you might want to take a peek at the advance springs under the points.
I know that when I changed over to a pertronix system (highly recommended...no more points to mess with!) I found that one of the springs on mine was broken. You can find much info in the archives on the pertronix units.
David 55 TF1500 #7427
David Sheward

Okay everyone,
I changed the plug leads (made my own from Napa stock plug wire!). Made little if any difference. (Didn't change condensor, points, etc. because will have to order those from Moss.) Then put in brand new plugs. RUNS GREAT NOW! BUT - the plugs foul within minutes again - just like my original pictures!!
My jets are centered, pistons drop like bricks, down to 3 flats on the jets, all that other good advice above. Could it still be the timing (I haven't delved there again yet)? I've also noticed 2 other things since:
1. One piston dampener has a small hole in the top, one doesn't. (YouTube.com warned about this!) And the bolts that hold the float chambers to the carb have different head sizes. The carbs are obviously not a "matched set" (no surpise there!) But I've not mixed up the parts-I'm sure of that!
2. To obtain an idle below about 1200 rpm (with a warm engine) you must physically move the throttle shaft with your hand. The idle adjusting screws don't even make contact unless you do this. In other words, the butterfly's won't close far enough on their own. I've cleaned all their parts but did not rebuild the shafts, etc. Spraying carb cleaner all over them while running does NOT change engine running at all, so I don't think they "leak".
I think I'm getting there - sooooo close I can taste it!
Thoughts?
Ed
efh Ed

Next step for me would be to remove both dash pots and pistons and have a look at the butterfly's and see why they are not fully closing or why the Idle screws are not returning to the stops. I'd check that the jets are fully up and not being held down with the choke . I'd have a look at the fuel level in the jet tubes while I had the pistons out and see that the fuel is about an 1/8" or so below the carb bridge. The fuel issue sould be settled before anything else.

LaVerne
LaVerne

Ed, there are springs on both ends of the throttle shaft. If their pre-tension or pre-load is too little, than the cilinders vacuum opens the trottle causing high idle speed. I learned that those springs must have a pretty high pre-load. Watch out for your fingers when you use a srewdriver to re-adjust them. Greetings, Huib
Huib Bruijstens

I might have missed it, but I did not see anyone suggesting that you watch the pistons in the carbs as you rev the engine. Make sure that they are rising significantly and in unison.
David Lieb

Huib, your assesment of the shafts sounds like what I'm seeing. The vacuum does seem to be holding the throttle open. I'll try adjusting it. Thanks!

David, I've been watching those pistons all along and I checked balance with a hose (haven't gone for Unisyn yet). All looks normal there.

Laverne, The jets are indeed up all the way (I don't even need to choke start it up here.) I've read lots of posts about "looking at the fuel level in the jet" in archives, etc. but when I look in there with pistons out I don't see any fuel, even with ignition on/pump running! Am I misunderstanding? (Someone also suggested looking down thru the pistons with damper off also. I can't do that. It is not a through shot thru piston to jet. Maybe I misread it?)

Anybody have thoughts on why one damper has a breather hole and one doesn't? Is that critical?

Getting closer! I just drove it on my first trip over 3 miles since purchase. Drove about 25 miles. Took it up to 60 mph. Was a little scarey but a whole lot of fun! Got lots of "thumbs up" from locals as well.

Ed
efh Ed

Ed,

What we're looking for on the fuel is the level that is in the float bowl. The level in the bowl will be the same height as the fuel in the jet tube. If you see that the fuel was at the same level as the bridge or high enough to be over the top of the bridge then you will never be able to lean the mixture out to tuneable levels. If you can't see the fuel, pull the piston out and wipe the needle dry and reinsert the piston and examine the needle for fuel depth.. like checking your oil. Should be done after turning the key on for a bit to make sure you haven't dropped the level down from evaporation. Leave the key on while you doing this in case you have a float needle that isn't seating , in which case you will see the fuel running out the over flow pipe or out the top of the jet tube.I don't think there is any chance you are going to find the level to low from the symptoms you have described. I can't say on the damper hole as I know the earlier ones did not have one but during the production it was changed to remedy some problem. Both should have been the same. Have'nt a clue if mixing the two would cause any issues.

LaVerne
LaVerne

Is there a video somewhere that shows exactly how to check the fuel level at the bridge? It seems to be one of the things that are really hard to get a mental image of. I've never done it, and I think I have a higher than recommended level in my front carb. Is the procedure :

1- Remove the dashpot and piston. Make sure the float bowls have filled.

2- Look at the top of the jet to make sure the fuel isn't right up to the hole that the needle goes in, but just 1/6" to 1/8" below.

3- Adjust float level to make this level correct, filling float bowls each time you replace the float cover.

4- Replace piston and dashpot, and check jet centering.

Those of you that have done it a few times may just do and look for things automatically which are not second nature to us novices with these fascinating carbs.

Thanks for your help, all of you!
Tom

Tom, I found that looking into a 1 mm hole is not easy at all. So, between your number 1 and 2, pulling the choke to bring the jet down as far as possible. Now, you're looking into a 7 mm hole and might spot the fuellevel down there. What I did next it to push back the choke to bring up the jet, slowly till the top of the jet equals the fuellevel. Than I toke my ruler and measured the depth from the top of the jet to the bridge. Enjoy and greetings, Huib
Huib Bruijstens

"One damper has a hole, and one doesn't" It won't run worth a darn like that if stock TD carbs. The later TF carbs had a vent hole in the body of the chamber (or somewhere), so those dampers had no vent. The TC/TD chambers have no external vent, so without a vent hole in the top of the damper, air pressure will keep the piston from rising. A freind had this exact problem- I don't remember exactly how it ran, but it was badly. George
George Butz

The TD carbs were vented through a hole in the dampener cap, whereas the later carbs had the vent hole in neck of the piston chamber body. Either method will work, but a hole is required to allow the piston to fall back down.
What would get you in trouble is if the one carb was vented through the cap and the other through the body, and the caps have been switched- with a solid cap on a solid body.

Dallas
D C Congleton

Well, my carb with the vent hole in the cap piston rise & fall fine. So does the one without the hole - yet I can find no vent in it's body! So I took piston chamber off car, turned it upside down in a bowl of water and pushed on the piston. The one with the hole air bubbles comes right out of the hole as expected. The one without the hole air comes out between the cap and it's gasket - even if I really tighten it up! Both pistons do rise and fall properly when running in the car I should add. Sounds like a real mismatch of parts, but it seems to work! Go figure?

Still no luck visualizing fuel level in jet. I tried Huib's idea of dropping the jets until can see fuel then bringing them back up. That works on one carb, but I see nothing on the other. Also tried using the needle like a "dip stick", same results. But both carbs are burning fuel when running! I can see it by lifting pistons and looking in there (scarey!).

Just took another run today and it still runs good. Still idels fast but I haven't played with throttle shaft springs (looks scarey!). I pulled plugs and they are sooty around threads but electrodes are clean as I would imagine they should be. Maybe my whole problem has been that this car has not been out on the road in at least a year and just needed to be "blown out" as we used to say. If so, I've learned a lot from you guys and maybe I can move on to more "fun" stuff like paint, interior, etc. I sure hope so!!! Watch for my next thread!
efh Ed

Ed, among the first steps in reassembling our carburetors is to assure that the butterflies (throttle valves) fit properly in the bores and that you can't even see light around them when closed. That's when you tighten down the screws that attach them to the shafts. The butterflies must be installed properly so that the bevelled surface closes against the bore. You then install the springs and adjust them so as to keep the throttle valves closed against the spring tension. If yours are not closed under no-throttle conditions - you have a problem.

What did you use as a guide when rebuilding your carburetors? I highly recommend the video by Lawrie Alexander that is sold by Moss.
Bud Krueger

Ed, do not assume the capacitor is OK even if brand new. Change it just to humor me.
Baz

Bud, I did not purchase the butterfly parts (the "Master" rebuild kit). I just did the basic rebuild kit - it was cheaper - jets and float parts. I did not remove carbs from engine, just the jets and float chamber. I know, I know, a penny saved...I guess I will have to remove the carbs and really inspect/learn the butterfly parts as well to get the idle down. But I wanted to have a little fun with the car on the road before the snow flys here.

Baz, I'm making a Moss list today, including condenser, points, etc. But what is a "capacitor"? Another name for "condensor"? (I told you I'm new at this!)

Any thoughts on my "blow it out" theory above by the way? Maybe cylinder heads were carboned up or something like that from lack of use??

Thanks guys,
Ed
efh Ed

Ed, capacitor, condencer all sameo sameo.
Cheers
Baz

Ed, I suspect that the last person to reassemble your carburetors skipped the step about centering the throttle valves. They mount diagonally in the bores and are bevelled on the edges to mate up with the cylindrical bores. If they're not installed properly you will have one heckuva time trying to get them adjusted properly.

BTW, the 'condensor' is a capacitor of approximately 0.25 micofarads.
Bud Krueger

Ed, drill a hole in the cap without. Yes, the threads may leak air, but you need a hole with no resistance. Fix stuff correctly or it will bite you later. Have you lubed the throttle shafts? They do get sticky. While running, put a couple drops of oil on the shaft next to the carb body on both sides, then rev it a few times- this will suck the oil in. The coil springs on the end must have tension to close the throttles also. Real simple to adjust- loosen the connecting bar between the carbs, loosen or disconnet the throttle link. Each carb shoud snap shut if the spring is correct. If not, just loosen the tiny bolt at the outside of the spring enough to rotate the spring seat, and rotate it for more tension (ie wind it up), then tighten. Also, do you have a good throttle pedal return spring in place? Lube the pedal shaft pivots inside the firewall as well. George
George Butz

ED,
"thoughts on my "blow it out" theory above"....
I haven't had my car out for a year also.
My "plan" is to buy a few gallons of hi-octain racing fuel to add before I try to run it on what is in the tank.
As a post note I would say that when stored I had added fuel stabalizer to my tank and I do run a clear filter on my fuel line so I can see if the fuel is gunked up before it get into the carbs.
If the filter looks bad I will drain the fuel before running. I have had pretty good luck with this in the past.
Did you get a chance to look at the advance springs in the dizzy?
If you go back in the archives you'll find some comments I made years ago about how my car was running when I first purchased it. People poke fun at these little cars and how "unreliable" they are ...I still contend that after seeing what all was wrong with mine, I was amazed that it ran at all!
Cheers,
David 55 TF1500 #7427
David Sheward

Ed Make shure both the walves on # 1 cyl is closed when the piston is on tdc. the rotor in the ditributer shall then poit at # 1
plug wire, then arange the other wires in correct fireing order. I failed there once
Thoralf
t g sorensen

Bud, Okay I took 'em off to inspect the butterflys. I'm not sure the bevel is facing the correct direction? Also, the photo attached is from the front with a flashlight held behind the butterfly. The goldish "ring" behind the butterfly is the light shining through. From what you say, I should not see any light, correct? Both carbs look this way. I'll insert another post with a photo of the bevel.

efh Ed

Picture of butterfly being held open showing bevel (I hope!)

efh Ed

Ed, it looks as if the butterfly is 180 out. The bevels should contact the walls of the cylinder when closed. What you have to do is more easily accomplished if the spring tension is released. Loosen and remove the two retaining screws that hold the throttle disc into the throttle spindle. Pull out the disc. Looking at it will show that one edge of each diametrically opposed side will be bevelled. These bevelled edges are to be in contact with the cylinder walls when the throttle is closed. Reinsert the disc into the spindle so that the bevelled surfaces will contact the walls and then tighten down the retaining screws. The screws are probably split so that they can be spread somewhat to avoid loosening. Reassert the return spring tension and try again. Ideally, you should see no light around the edges, or very little. Good luck - Bud.
Bud Krueger

Ed, Bud may be right, but I can't tell from the picture on my monitor. Again, the beveled (wide and angled) part should contact the aluminum body when shut. If the sharp edged side is what touches , you will see the beveled side facing toward you(which is wrong). I would replace the screws if you remove them- definite risk of cracking if you straighten and re-bend. Don't want to suck a piece of a screw into the motor! George
George Butz

I might have missed it some where in this thread, but Thoralf and I still are not sure if number one wire is correctly connected to number one cylinder when the timing marks are at TDC..


SPW
Steve Wincze

Steve,
The wires were clearly marked by PO's MG shop as was the top of the distr. I haven't got back to the timing again but it's on my list before I consider this case "solved". Thanks for your interest!!
Ed
efh Ed

Bud/George,
I have not removed the butterfly's yet because I don't have replacement split screws yet but I have a question. By "one edge of each diametrically opposed side will be bevelled" do you mean that the bevel should be facing one way on side A of the disc and facing the OTHER way on side B? That would make sense I think. But I'm not sure my discs are made that way! If the bevel was all on side A it would only be flush with the cylinder wall on the top (or bottom) and the sharp side would be opposite, no??
I'll know for sure once I remove them but this has me baffled. Or am I misunderstanding you? (My carb books don't have a very good picture of the disc! That would clear it up!)
Ed
efh Ed

Ed, they are beveled on opposite sides. The taller edge is away from the direction of closing movement if that makes sense to you. You should be able to see the angled edge if you have the carbs off and hold the butterfly fully open. You will have to have the carbs off the car to remove the split screws and the butterfly plate.

LaVerne
LED DOWNEY

Ed, if you'll send me your 'snailmail' address (off list) I'll send you some images that will help appreciably. Bud
Bud Krueger

Bud, your email link above bounced ):
It looks like my discs are indeed installed backwards however. Those screws that hold the springs in place are a bear to remove! The screwdriver slot is not very deep and one is already messed up by a PO. Any tips on removing them?
efh Ed

Ed - You may have to remove the carburetors in order to get the screws out. The screws are split at the ends and spread after tightening to keep them from working loose. If the previous owner spread the tips completely apart or used locktite on the screws, it will require closing the tips of the screws and heating the screws to loosen the locktite. Cheers - Dave
David DuBois

ED, I have no idea how my old email address has resurfaced. It's budkrueger@comcast.net or Bud@ttalk.info
Sorry about that. Now to try and straighten it out.
Bud Krueger

Final report:
Butterfly's have been removed and inserted correctly! They were indeed 180 degrees backwards! It's amazing these cars can even run sometimes! Polished carbs, reinstalled, started on first crank! I'm now able to set idle to whatever I want it to be, not just 1,500rpm like before. It makes a big difference if the discs can close all the way!!!
Thanks to all those that have helped on this one. I think it's safe to roll this one over to archives should some poor future owner have the same problem.
Case closed!
Ed
efh Ed

"It's amazing these cars can even run sometimes!"
Amen to that...anybody that would read my old thread on "Vapor Lock" from years ago would be as amazed as I was was that my car ran at all. How these little cars ever got a reputation for being unreliable is a mystery to me! My carbs were a mess (one float upside-down the other had a hole in it, jets wrong size & bent, no oil in one of the dash pots...ect ect ect) my wiring was a mess ...."Izzy's" aka at that time should have been "Sparky"....but the little bugger still ran ....maybe not real far....but she still ran. I have been laughing lately at the car commercial on TV that proclaims "23 sensor's to monitor the the 68 sensors" (or how ever many it is)... if you read between the lines...only thing missing is the 47 mechanics and 12 computers it takes to figure out what one keeps the beast from starting or "deep frying" yer buttocks with the heated seats or a warm summers day! LOL
K.I.S.S. ~~~~~~~ !!!! LBC's FOREVER!!!!
Cheers,
David 55 TF1500 #7427
David Sheward

I maintain it's the points.

Denis
Denis L Baggi

This thread was discussed between 11/11/2007 and 07/12/2007

MG TD TF 1500 index

This thread is from the archive. The Live MG TD TF 1500 BBS is active now.