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MG TD TF 1500 - Can't get the engine to idle down.

Good day all.
Got the broken crank fixed, the brakes working. Now I can't seem to get the engine to idle below about 1200 RPM's. Disconnected the linkage to the gas petal and all three of the engine speed screws are slack. Still 1200 RPM’s any ideas?
Thanks in advance , John
John Hambleton

John, any chance that you did any work on the carburetors? That symptom is often caused by throttle discs that aren't centered. Bud
Bud Krueger


John, loosen one of the little bolts on the connecting shaft link between the carbs to make sure both carb butterfly discs can close all the way.
Richard Cameron

Good suggestions, but an air leak will cause the same problem. Manifold gaskets, carb mounting, loose carb spindles, etc.
Dave H
Dave Hill

One other thing to check...make sure that when the choke is pushed on (turned off), the cable returns the jet all the way up in the carb
Charles Duffy

Charles
I had a similar problem and found I had air being sucked in around the manifold. This can be checked by spraying CRC or Brake cleaner along the manifold. If the RPM increases there is a leak and you either tighten the manifold bolts or loosen the manifolds and use some goo on the manifold gasket to block the sucking.
cheers Stuart
Stuart Duncan

Also check your timing. Too advanced and the idle can run high. And definitely disconnect the linkage between carbs to see if one is hanging up.
Steve Simmons

When linkage is disconnected, manually open the throttles, let go and it should snap shut. That would verify nothing is sticking and that the return springs on the shaft ends are adjusted correctly.
George Butz III

I had exactly the same problem and only recently solved it by fiting a small universal joint in the rod that connects the throttle spindles on the two carbs. The cure has been so successful that I have been able to slacken off the return springs and now have a really nice pedal feel. The holes in the carb flanges are slightly bigger than the studs so the carbs can be rotated slightly and with there being several gaskets between the flanges miss alignment of the spindles is a real possibility. I bought a 8mm x 8mm universal joint on ebay for £3.


J Targosz

Dear mr Targosz, a fantastic idea .Congratulations.

Gerard
Gerard Hengeveld

Thanks everyone, as soon as the garage warms up I’ll check all your suggestions! Thanks again John
John Hambleton

Jan,

Glad you forwarded your solution - Seems like this spindle misalignment issue could be a problem to many?

David
David Padgett

As it turned out it was the linkage between the two carbs. Thanks again for your help. John
John Hambleton

Remember this recent thread and the correct observation from David.
https://mg-cars.org.uk/cgi-bin/or17?runprog=mgbbs&access=&mode=archiveth&subject=8&subjectar=8&thread=201901011106518410

Laurent.
LC Laurent31

I like the U-joint. I had this problem til I loostened the carbs to re-settle the binding shaft.
MAndrus

Re-activating for u-joint Bud
Bud Krueger

The U-joint is brilliant but isn't the little spring clamp thing to the right supposed to fill that role?

Clearly the U joint does a superior job.
Christopher Couper

This thread was discussed between 30/01/2019 and 29/07/2019

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