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MG TD TF 1500 - Rough Running TD

Hello all:
I recently purchased a '51 TD. For whatever reason I cannot get the motor to idle smoothly, or when I give it gas it sputters a lot and will not run smoothly or develop power. I recently installed a pertronix module instead of the breaker points, which improved it somewhat bot didnt cure the issue. The timing and valves are set properly. The distributor cap and wires are fine. I balanced the carbs. The carb floats were set to 3/8' drop on the levers. I have run the jets up and down to no avail. Im pulling my hair out. Im bald already and cant afford to lose any more! Any suggestions greatly appreciated.
Thanks,
Mark

mhb Mark

Distributor cap wired incorrectly? Carbon tracing inside the cap? Spark plug plug wires leaking down, wrong heat range spark plugs, wrong plug for head design? Low compression? ...., ?
W A Chasser

Carb floats filled with fuel? It doesn’t have to be a lot.

Stuart
S Grimm

Leak from either inlet/exhaust manifold(s)?

Rhys
R Alexander

Try replacing secondary coil wire.

Cheers

Gary

79 MGB
gary hansen

You are faced with a tedious task, the only way to resolve this will be a continuous process of elimination doing one thing at a time.

Attempt to split your processes, mechanical, ignition and fuel.

Plenty of good advise contained in previous posts. I would also suggest:

Check electrical connection security and grounds, confirm no air leakage at induction manifold and carburetors with engine running and squirting brake cleaner onto all joining surfaces, listen for rev changes.

Look for changes in valve clearances who knows what condition the cam and followers are in.

What oil are you running in your dashpots, I recommend ATF and going back to basics with carburetor settings and condition of components.

Ensure the distributor drive is not slipping and the cam is not damaged or loose. This may sound out of left field, I had a brand new car where the dizzy drive gear was not pinned to the shaft.

Graeme

G Evans

Try pulling out the choke when you are spluttering, to see if the carbs are misadjusted.

Tom Lange
MGT Repair
t lange

Also:


Don't forget that there should be an external ground wire going from the distributer to the block.

Jim B.
JA Benjamin

The first thing I would do on a newly acquired car with these problems, is a compression test.

John
J Scragg

If EVERYTHING checks out as OK (compression, carbys, dizzy elecrical etc.) perhaps it is the camshaft? Either it has a high overlap cam or the camshaft has been timed incorrectly?
Good luck with the diagnosis.
Bob
R L Schapel

My humble opinion things point to fuel/carburation. If not capable of increased revs then initially I'd question fuel supply. If proved in order then is the ignition system capable of supplying the increase current requirement. So condener then coil.
JK Mazgaj

look also fir butterfly adjustment or carb shaft play.

Laurent
LC Laurent31

Also check that both carbs are opening, easily missed
Ray TF 2884
Ray Lee

If it runs alright and sputters under changes in acceleration you might check the end float on the distributor shaft. Mine was well above spec and caused rough running - if the end float is excessive the helical cut gear rises and falls on the cam gear causing timing changes.

BobbyG
Bobby Galvez

Mark
Just reading back through the comments here and to me the obvious would be a float half full of fuel maybe or -----What clearance did you set the valves at
William Revit

Mark---------------------?
You still about man
William Revit

Pulkl plugs and check the color. While they're out give it a compression test. Another quick test is spray starting fluid around the carbs and intake looking for vacuum leaks.

It reminds me of a friend's TD that ran very poorly and showed a touch of oil smoke. I suggested he double check the oil level in the air cleaner. He said it was good. A month later when I next saw him, he said he discovered his problem- too much oil in the air cleaner.
JIM N

This thread was discussed between 05/06/2020 and 11/06/2020

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