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MG MGA - No fuel

I pulled the MGA 1500 out of storage after a long winter’s sleep. Storage is 15 miles from the home garage so only a quick check was done before moving the car out of storage. All fluids checked out was fine. The car started smartly and it ran fine. I drove a few miles to a store on the way home. After sitting 10 minutes, the engine would fire but not start. After cranking for a while, no fire at all. I checked spark, which was fine. The pulled spark plugs were all dry so I turned to the fuel side of operations.

The fuel pump was ticking appropriately. Fuel appeared in my clear filter located between the fuel pump and the twin SUs. I pulled the float chamber lids and both had fuel. The accelerator and choke cables were attached and functioning normally. Still no fire. So I banged around some more by the carburetors, as ham-handed owners without an idea what to do next are prone to do,eventually leading to a substantial fuel leak at the grommet on the front “holding up” bolt that attaches the bowl to the carb. Then, with fuel running out of the newly cracked grommet, I cranked the engine and it started right up. However, the engine raced to about 3000 rpm and climbing. The accelerator was not stuck but also had no effect on engine speed.

I have now pulled the carbs off for a complete run-through. But I am stumped by the situation. Anyone have ideas or similar experiences? My concern is that the grommets clearly need replacing but that there might be another problem or a group of other problems that need resolution as well. Thank you for your ideas.
Daniel Crothers

Here's a guess: Pistons stuck in an up position prevented the car from restarting. The banging released the pistons but also opened a significant air leak somewhere on the engine side of the carb throttle plate. Perhaps the vacuum connection was loosened or an old brittle gasket cracked enough to allow significant air entry, allowing a "runaway" engine.
JM Morris

Throttle cable outer jacket lifting up out of the socket on the bracket and sitting on top, makes for very fast idle. One of the accordion clamps on the throttle shaft between the carbs may slip. This can hold one throttle plate partly open causing very fast idle. Pull and release choke, sets the fast isle cam, and that might stick and not return to rest.
Barney Gaylord

I did not pull the filters and check location of the pistons while I was having problems so that is a "maybe." One piston is dirtier than I wanted to see so that is a real "maybe." While on the scene, I did check the throttle cable and that was ok, as was the cam. I just separated the carbs and the accordion clamps were tight. So nothing else is apparent wrong.
I was going to send the carbs somewhere for a rebuild. But the archives talked me into ordering a kit and getting dirty. Two more questions. Is the Moss kit ok? Which one; the "master rebuild kit" or the "carb. rebuild kit." If not Moss, who and where should I get the kit? Second, there is a fair amount of play in the pivot pin of both the front and rear levers and the fast idle cam. The fast idle cam play is for the fast idle without engaging the choke, as I recall. But I am wondering if significant play is normal or are these parts worn and need replacement. Again, many thanks.
Daniel Crothers


I hate to see you go to the expense of a rebuild kit especially since the car did so well right out of storage. It's probably just a cleaning and gaskets issue.

But if you decide to do it anyway, which kit depends on the condition of your throttle shafts. If there is a lot of play (slop) between the throttle shafts and the carb body, especially at rest (throttles closed and slightly open), then you would need the master rebuild kit which includes new throttle shafts.

I got my kit from Moss but that's not necessarily a recommendation. There may be better sources out there. You might want to take a look at what Joe Curto offers (google Joe Curto, Inc).

Don't be fooled by the play in the choke levers. I was--and discovered that the new levers had about the same amount of play. I could easily have continued use of the original levers. Take a close look at the various bores in your choke levers. If they are not outrageously worn, normal carb choke adjustments will take up a considerable amount of play. But a few pivot pin replacements might be in order. And as you note, there's supposed to be some play in regard to the fast idle cam adjustment.

Lastly, be sure to read Barney's carb articles at mgaguru.com before you take these plunges (if you haven't already).

Good luck! Let us know how it goes and what you find.
JM Morris


Daniel--P.S.:

I'm using the teflon seals per one of Barney's articles (but I'm still having stiction problems). If you decide to rebuild and would like to try this, I have a pack of 50 (only needed 4) and would be glad to mail you 4 of these.
JM Morris

JM, -- You need 8 Teflon O-rings to do 2 carbs. Use 2 O-rings in place of each original seal. It would likely leak using single O-rings. If the jets stick, try polishing the OD of the jets. I can nudge mine up/down very easily with one finger.
Barney Gaylord


Thank you so much, Barney! Somehow, I missed that, although 4 have been holding it, but with only a few miles on 'em at this point. Will redo with 8.

Is 400 grit emery cloth too strong (rough) for polishing?

Daniel--I'll send you 8, if you like.
JM Morris

If the jet OD looks particularly dirty or corroded, then maybe 400 to clean it up, and follow with 600. The idea is to make it clean and smooth to allow it to slide easily through the seals.
Barney Gaylord

Barney--believe it or not, my jets are brand new. They came with the rebuild kit from Moss. Another reason I was surprised with the stiction. I think I'll take measurement comparisons between the old and new jets on the off chance there's a manufacturing error or I got a batch on the fat side of the tolerance allowances. And I'll check the measurements on the seals too--just to be sure.

Won't be able to report back until Friday or Saturday. (My workshop is 23 miles from where I live and work, so I work there on the weekends.)

Note to Daniel: If you order either the standard or master rebuild kit from Moss, let me know if you get part #370-220 in your kit. It's a cup washer (illustration #16). It was left out of the standard kit I ordered. When I brought this to Moss's attention on my next order (comments section of an internet order) I received a short cute reply on the invoice of the next shipment next to that part number simply stating "not provided with the kit". Yet it plainly shows as being a part of the kit both in their paper catalog and their internet catalog. I was able to clean up the old ones (made of aluminum) with no problems. But it still irks me.
JM Morris

Jack and Barney, thank you for the suggestions and offers. Time has been limited so I have not been able to get farther into the carburetors. The little bit of cleaning and checking I have done confirms my throttle shafts are ok so I do not need the master rebuild kits. I am going to pull the jets to see if I need more parts in there from the rebuild kit, otherwise I am going to just get the gasket kit. I will keep you posted.
Dan
Daniel Crothers


Update: Measurements were taken on the new jets and the teflon seals. They appear to be fine. I polished the jets with 600 grit, went to 4 seals per jet, and I still have the stiction problem. But the front ones appear to be loosening up some. I guess it's just a matter of wearing them in. They seem to be doing better after getting them hot with driving. The next time I do this, I think I'll run some every cloth around the ID of the seals.
JM Morris

I find that a superior polishing on the jets is needed. I always buff them to a high polish on a buffer wheel using red rouge.
Sandy
SANDY SANDERS

Oh hello,I'm Sandy and this is my friend Julian,Seriously though, I do find that Shocking Pink, especially when it matches my nails is so much more PROMINENT than Red Rouge whenever I'm working on the car-------oh hello Sandy.Right I'll get me coat
MR Blencowe

I think MRB's last comment might require some explanation http://www.youtube.com/watch?v=ps87aOHorv4
Geoff Everitt

I had almost forgotten how funny "Round the Horne " was on radio back in the 60s, that sure is a long time ago MRB!

I expect your response will go down about as well as mine did last year to the US post about "leopard skin chassis bed liners". I knew they were actually pleasingly patterned MGA floor insulating material but my take on it was that they sounded a little more like something absorbant an incontinent geriatric like me would need overnight to keep my mattress dry overnight!!

Wasnt too well received!!

Colyn
Colyn Firth

I, for one, appreciate the humor I see on this forum. It tones down the serious "issues" we fret over. "let 'er rip!"
JM Morris

Thanks JM

I figured that so long as I occasionally answer a question in a useful, practical and almost serious manner, then maybe you guys would forgive me my more ridiculous replies!

Sorry that I havent been much use on this thread

Colyn
Colyn Firth

Well,it's just that some of us have been around a LOOOOOOONG time.I got my fist car a '47 TC in Jan '66 and it looked ancient but was actually only 19 years old .Now my F VVC is '97 and is now therefore over 13 years old but still looks modern ,almost futuristic and, IMHO, fantastic even after over 10 years of ownership.

Hi Sandy.How are the 'gators doin'?.
MR Blencowe

JM,

My parts have arrived, and I am finally back at the workbench working on cleaning parts and getting my carbs back together.

Answering your question posted on May 18, I did order the standard SU rebuild sold by Moss. The kid does not have part #370-220, which is the cup washer. Now, as when you ordered, the catalog says two of these washers are included. That turns out not to be the case.

I am putting my carbs back together with the cork seals. I had the rubber o-rings in the prior build and they are not in good shape. I will keep your offer of the Teflon rings in mind when I see how things progress from the kit. With any luck, I will get the 'A on the road this weekend! Thanks again for the advice and encouragement.
Dan
Daniel Crothers

Dan. For SU parts, here in the US, Joe Curto is the best source possible. He has an extensive knowledge of the SU carbs, keeps a large supply on hand, and, as a professional rebuilder, knows what the rebuild kits contain and what other parts might need to be ordered. I suggest you do a websearch and contact him. He has been very helpful to me in the past.

Les
Les Bengtson

Thanks, Les. I have Joe's contact information from when I was going to send the carbs off for rebuild. This Forum then talked me into learning more about this part of my car so I dove in and am doing the work. However, your advice about ordering rebuild parts from someone in the know is a good one, and advice that I will follow in the future.

As for the missing washers, like JM, my old parts are serviceable so there is no harm. Just disappointment that the parts continue to be listed in the catalog when they clearly are not included in the kit.
Daniel Crothers


Plus, Joe Curto is somewhat of a character. More interesting and fun to deal with. The EXACT opposite of dealing with the clock-punching-robots at VB.

After my experience with sticking jets, Sandy's comments make darn good sense. ("Round the Horne" not withstanding :)
JM Morris

This thread was discussed between 17/05/2010 and 17/06/2010

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