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MGC MGC stumbles/stalls after warming up....

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rick_ingram

rick_ingram

Yoda
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The 1969 MGC (stock engine, automatic transmission) has developed a new problem.

Timing set at 14BTDC as per Schlemmer suggests with this rebuilt dizzy.

Fuel pump is an electronic "square box" that delivers at about 3 psi.

Temperature gauge running about one needle to the right of "N"...which is actually rather cool for this car.

Starts fine and idles sweet at about 950rpm (where I like it). Acceleration very good when first starting a trip.

I took the car on a 15 minute run today to fill the tank with fuel.

After starting the car after the fuel stop, it began to stumble upon acceleration and even though I could run at speed (70mph), when I slowed for a stop sign or turn, the idle was eratic.

This happened last month in Indy to the point where the car died at stop signs and would barely start....I had to nurse her back to the hotel.

After cooling down, the car runs fine...and in fact ran the two hours from Indy to home fine....until I reached the top of the exit ramp and had to stop....where>>>it repeated the last paragraph.

Does this sound like fuel delivery?????
 
Posted this on the Healey forum.

Went through a similar problem. After doing all the somewhat obvious, rebuilding, cleaning, checking, rechecking etc. It was the draw tube in the gas tank. The recently completely cleaned and coated tank still had what looked like sand blasting material in it. After a run it would clog up the draw tube. I assume it would then fall back out when sitting so car ran great for awhile then acted up.

A really simple problem that cost a bunch to find and little to fix.
 
check your spark plugs, you can get the same symptoms with a to rich mixture - if they are sooty, lean them out some.
 
One suggestion might be to check the fuel tank vent line that runs from the carbon canister back to the tank,seems to me like a plugged vent line might give those symptoms too.
Good luck......Mark
 
OK...Ran the car to operating temps; started stumbling. Pulled float bowl lids. Gas at a good level, nothing coming out of overflow tubes. Float free, needle free. A *little* sediment in the bowls (insignificant). Overflow tubes clear of any obstructions. Next step-pull plugs and look how the cylinders are burning. <sigh>
 
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