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MG TD TF 1500 - Engine suddenly runs very rough

FIRST THINGS FIRST - I am NOT an experienced mechanic, per se. I know my way around the engine, but I've never taken one completely apart (I did remove my MGA engine, rebuilt the clutch, cleaned up the engine, replaced it). Having said that, here's my problem. The '54 TF 1250 I bought in July has a Laystall-Lucas aluminum head (made in 1952 by XPAG Engineering), with a high-lift cam, split manifold and dual exhaust with glasspack mufflers (which I don't particularly care for). I took delivery on the car at the end of August. I drove it locally, and the engine was "noisy" with what I thought was excessive valve clatter, and it had an intermittent miss. About three weeks ago, my local MG guru adjusted the valve clearances per spex from XPAG Engineering, replaced the plug wires, sorted out some electrical issues and adjusted the carburetors (he recommended they be rebuilt, which is on my squawk sheet). The engine ran MUCH better, more like I thought it should. At his suggestion, I ordered points, condenser, rotor and plugs. I have now replaced the points, condenser and rotor, but not the plugs. The last couple of times I drove the car, it's had an intermittent miss, which has now developed into an absolute refusal to run smoothly. The engine bogs down when I accelerate and it won't idle at dies, if left to idle. I looked at the plugs last night and they were very oily......with pooled oil I the plug wells. I cleaned them, replaced them, started the engine and it still runs very poorly. I have checked the coil, by swapping the one from my joy. I'm open to thoughts and suggestions. Thanks for your input.
Frank Bice

Swap out the new condenser for the old one...many of the new ones are garbage.
Gene Gillam

Frank -

Five condensers have failed in my TF-1500 this year, including two from Moss. Same symptoms as you describe.

I'm using a condenser for a 1978 Plymouth Arrow now. No problem for the couple of months that it's been in the car. Smaller than most condensers. The mounting "ear" is a perfect match for the breaker plate in my original Lucas D2A 40367B distributor. Can't beat the price ... $1.99.

Advance Auto Parts BWD G635


LM Cook

May be condenser, but always change plugs if running problem. Make sure the rotor is red, not black or brown. George
George Butz

Where were the other 3 from Lonnie? I ask so I can also add them to my very short list of suppliers to avoid!

What really burns me up is on most of the threads I read on this forum somebody identifies yet another part from "you know who" that proves to be a total waste of time & money & even some items like the ignition switch which has the potential to actually set fire to the car! Over the past year I've compiled a list of parts YKW sells that are about as useful as tits on a bull. It's now well over twenty items & growing. I was so peeved I rang the CEO of the Western Division of YKW early in the year to complain. He promised he would "look into it" & "do something about it" & "he'd get back to me". On the same day I followed it up with a detailed email listing about 17 useless items. That was 7 months ago.. I've heard nothing since...

Them's my thoughts Frank. I now only buy from AS, B&G, Cambridge Parts & am about to order some TD stuff common to TC's from FTFU. My suggestion would be to strongly urge that you & every other TD/TF owner seriously consider doing the same. Maybe then "You Know Who" might get the message & lift their game! On a more positive note I hope Gene & Lonnie's suggestion gets your problem sorted. Cheers
Peter TD 5801
P Hehir

Peter - I am not so sure that the supplier you are referring to is really to blame when it comes to capacitors (condensers) and brake light switches (not addressed in your post). With all of the cars manufactured today, none of them use a capacitor in the ignition for the simple reason that they no longer use points. The result is that very few ignition capacitors are even being made and probably 99% of those that are made are made in China. The capacitors that I have seen recently, unless they are new old stock are junk, the same as brake light switches (with the exception of the switches sold by Ron Francis Wiring at US$32.00 each). The problem is not so much that of the resellers, who is trying to keep costs for the enthusiasts, but rather the supply of the parts from the manufactures. Personally, I would rather purchase a $32.00 brake light switch and get on that will hold up for more than 2 months, but when that happens there is an outcry from all of the enthusiasts about the unreasonable prices being charged by the same parts house that they were just yesterday complaining about the crappy parts being sold. Cheers - Dave
D W DuBois

Agree Dave. The fault lies with the manufacturer but the supplier has a duty of care to ensure the parts he on sells actually are fit for the purpose. Seems like Lonnie has found a capacitor that works. I've not had any major problems with the parts I'm sourcing from those suppliers I mentioned above. If they can supply parts fit for purpose & do it at competitive prices why can't YKW? I'd love to see YKW buy a wreck of a TD & try to restore it just using their parts. Now that would be a series I'd pay big money to watch! Cheers
Peter TD 5801
P Hehir

Peter - I think that this problem is going to get worse as time goes on, trying to find parts that are obsolete for the rest of the automotive world. The manufactures are just going to stop making things like ignition capacitors. I dodged the problem on our MGs by going to the Pertronics ignition, but those who don't want to do that are just at the mercy of the manufactures. The one thing that people with conventional ignitions to preclude the capacitor failure (or at least minimize it) is to quite changing out perfectly good capacitors when replacing points. The old style paper capacitor (used for ignition applications) don't wear out. I have seen some postings that say that they dry out over the years, but that is a mistaken belief. Electrolytic capacitors do dry out over the years, but paper capacitors don't have any electrolyte in them to dry out, so they very seldom fail, even after many years. If the capacitor in the ignition is not failing, don't replace it.

Lonnie apparently has found a source of some good capacitors. I will make a note of the P/N and source to let people know about them if they feel compelled to replace the existing capacitor that has been working fine, but I will still advise people not to change out a capacitor that has been working fine.

I mentioned the brake light switches and the fact that the only ones that are holding up are the very expensive ones from Ron Francis Wiring. after finishing on this BBS, I went over to the MG Experience forum to find a complaint about - you guessed it, the Ron Francis Wiring brake light switch that gave up the ghost after only three years. That is about the third or fourth complaint I have heard about those switches.

And yes, I agree about watching the suppliers try to restore a MG with nothing more than the parts that they sell. Cheers - Dave
D W DuBois


It could very well be a bad condensor,,,, When you say >>>with pooled oil I the plug wells<<<
I am assuming that you are describing the oil pooling around the area where the plug is in the head casting?? Is the oil coming from a leaking Valve cover gasket, and then shorting out the plug wires ???

Did your "MG Guru" say what was wrong with your carbs?? They could be way out of adjustment, or "gummed up ".. That would cause the poor running condition that you are describing,, What was the history of the car befor you bought it? Was it running??? or stored for a long time??

Steve Wincze

Thanks, guys for all your comments and suggestions. I will first try the suggested condenser, since I threw my old one out (lesson learned).

The "pooled oil" in the plugs wells (yes, the area in the head casting, around each plug) could have come from a leaky valve cover gasket (my first thought), except that my gasket is new and seals well. The old gasket was hard as a rock, hence the replacement just three weeks ago. After I cleaned the plugs, and wells, I re-installed the old plugs (not wanting to put my new ones in until I determine the source of the oil)and ran the engine (as poorly as it runs, it runs) briefly several times and re-checked the plugs....they are dry. My immediate objective is to get the engine running smoothly again, first by trying a different condenser. As for the carbs, the jet on the rear carb is leaking. After a drive, it leaks until the bowl is empty. Mike attempted to re-seat it, but it's beyond that. If Mike could've fixed the problems with the carbs, he would have. He has talent, but he refers one to the specialists at times. He's more than a "wrench"....he's a racer, having grown up in a shop FULL of Brit cars. He learned from his father, who was the OKC go-to guy for years before him. Before I bought the car in July, it had been driven sporadically by a college prof. He finally decided to sell the car because he just was not driving it, so yes, it sat quite a bit for several years. It's a beautiful little car, topside and below...but I am dealing with issues resulting from not being driven. I expected some of that, frankly, having two other MG cars. I know they must be driven regularly, to remain fully viable. I'll continue to post, as I gain experience in these matters. Thanks again. I solicit and welcome your comments.
Frank Bice

Peter -

My biggest challenge was finding a condenser with a clip that allowed the condenser to mount to my breaker plate without modification. I searched through every supplier that I could find on-line. I found ONLY TWO condensers with a mounting clip that would screw directly into the breaker plate on my TF distributor: Moss and Plymouth Arrow. FYI - the Plymouth Arrow condenser is 0.670" diam. Other condensers are about 0.690" diameter.

One Moss condenser failed within a month. The other failed within two blocks.

The other failures were ...

1) The original condenser. Looks to be supplied from factory. I also had a distributor problem that may have produced similar symptoms.

2) Beck/Arnley Part No. 172-5829, Advance Auto Parts. MGB condenser recommended on this BBS. However, the mounting clip did not match the mounting hole in my breaker plate. So I used a clip from another condenser. It barely gripped the tip of the condenser. Don't know if the condenser failed or if the clip slipped off.

3) Echlin ECH RR175 NAPA Auto Parts.
This condenser fits a gazillion American cars. I bought it to use in an external jumper between the low tension coil and distributor for emergencies. The base of the condenser was cracked where the metal shell was stamped into shape. NAPA replaced it. I made the jumper but haven't tested it.


Top: Echlin ECH RR175 with clips for emergency jumper.
Middle left: MG TD-TF condenser from British Parts Northwest Did not fit.
Bottom row left: Original condenser
Bottom row second: Moss 16-900
Bottom row third: Condenser for Plymouth Arrow
Bottom row right: Condenser for MGB

LM Cook

You know, I've always been a Moss fan for parts, but if I get a bad part, I'll call them and let them know about it, then I'll look elseware. But a condenser can be had from NAPPA for under 3 dollars and from Moss it'll cost over $15.00! So is the 15 dollar one better than the 3 dollar one? probably not. I like Lonnie's idea of using one for a 78 Plymouth Arrow, buck 80 from my local NAPPA. But then again, who made it? Only consolation there is, I can throw a bunch of them away verses throwing away $15.00 ones. JMHO. PJ
Paul S Jennings

IMHO, I would go after things that I KNOW are wrong first,,, like the carbs,,, then go after the things the MIGHT be wrong,, like the condenser. Heck,, it could also be the points,, what do they look like??


Steve Wincze

My first couple of minutes would be to make sure the battery is fully charged- low battery voltage will do what you describe as progressively worse running.

Then put a timing light on the coil wire and visually see for yourself whether you have consistent or inconsistent firing.

What is your point gap?

By the way, are you running old gas that came with it or have you tanked up with fresh fuel?

I agree with Paul.....I can toss a bunch of $2 condensers, but not $15 ones. Today I picked up a Brit made NOS condenser from a friend that had a Brit car shop for many years before he retired. He now just deals in parts....won't touch a car. Haven't installed it yet.
Steve, I had hoped to pull the carbs after Thanksgiving, when central Oklahoma weather is generally too cool to enjoy roadster driving. That may not work out for me, and I guess I can drive one of the other cars.
Jim, the battery is FULLY charged, made sure of that. Good suggestion, tho. Don't have a timing light any more....with 3 MGs, need to get another one, don't I?. The points are new, gapped at spec, .015 for the high lift distributor cam. Haven't checked dwell, need to do that. The fuel is new...but I can't say I'm POSITIVE there was not some sediment or water in the bottom of that tank, that has just now found it's way into the system, altho I have kept at least 6 fresh gallons in it. Need to check that out.
Didn't have time to touch the car today, won't tomorrow......maybe Saturday/Sunday. Again, thanks for all your comments.
Frank Bice

Among the easiest things, and therefore maybe one of the first things to check are the fuel filters. There's one behind each banjo bolt on the carburetors and one at the bottom of the fuel pump (on a TD, I don't know about the TF) and there may be additional filters in the fuel line. A clogged fuel filter was the genesis of my saga (removal and replacement of the head) that I hope to conclude today with the installation of the beautifully refurbished carburetors. Jud
J K Chapin

Good suggestions, Jud....added filter checks to my squawk sheet. BTW, who did your carbs? I'm looking at Joe Curto right now.

Happy to report to all that are following this thread, that the NOS condenser that I got yesterday from new friend Herb fixed my problem. Herb is retired from a Brit car shop he owned for years here in OKC, but still has some T Series parts it seems. Engine runs as smooth as silk now, in spite of the leaky carb and the fact that I have yet to replace the plugs. I have also discovered a likely source of the oil that was in my plug wells. The side cover gasket protrudes slightly above the bottoms of the plug wells and appears to be seeping a bit of oil, just enough to wet the wells. When I removed the plugs, each plug was withdrawn through the oily well, making me think the plugs were wet inside the head, which is apparently not the case. I'm happy this evening and very appreciative of all the helpful comments and suggestions from you guys. It truly takes a village, you know?
Until next time,
Frank Bice

Frank, I've heard Joe is good and I'm sure he is but I had mine done by Dave Braun and I'm VERY pleased. I also installed Tom Lange's tappet cover and valve cover gaskets and new Moss (LBC) crush washers for the oil line block to head and I have no topside oil leaks. Jud
J K Chapin

This thread was discussed between 29/10/2014 and 01/11/2014

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