What's wrong with the fuel system?, 914-6 w/ 40 PMO's won't start or idle (without assistance) Options

[david63]

It will become obvious that I am not the best mechanic in the world so keep that in mind when you hear my questions.

My 1970 914-6 (GT replica w/ twin plug 2.5) is not feeling too well. A job change kept me away from the car for several months and now you guessed it - it will not run.

What have I done so far... I suspect that the gas is bad so I drained the gas from the tank, replaced it with new gas (even put in a couple of gallons of high octane racing fuel (I know the fuel is OK now).

What the car is doing... It will start if I put a little gas in each carb (has 40 MM PMO's) it starts right up and NOW if I keep my foot in it I can keep it running. It will not idle and it does not hold a constant RPM with no change in throttle position?

I think the fuel psi could be the issue or there is something wrong with the carbs(different settings on the regulator between 3 psi and 9 psi do not seem to help or hurt)? Could the PMO's be plugged with crap (when I left the car sitting I ran it out of fuel prior to storing the car). Maybe the factory fuel pump is going bad. The car was set up like the GT with the factory fuel pump moved up front. Car ran fine before storage (actually would flood really easily prior to the storage period). Does someone rebuild the factory pumps as I have an extra that is leaking badly and thought I might re-build it and try that but would rather not just "swap parts".

Any thoughts, Thanks.

[naro914]

you may want to try this: run a bunch fuel system cleaner through it on a fairly empty tank. let it run for a while, shut it down and let it sit a day if you can. then start it up, run it again for as long as you can, then do what you said.

Back about 15 years ago, a good friend of mine owned a small Ford dealership and told me this: When you take your car for a 'Fuel System/Injector cleaning', all they do is hook up to a gas tank bypass and run pure system cleaner through it - for at the time $175!! He told me that instead of wasting the $$, to run your car almost to empty, put 3-4 qts of STP or some other fuel system cleaner in, start it up, and let it just idle there for a while (15-30 min). It will run very concentrated cleaner through it and really dissolve any build up. Mostly helps with the carbon build up in the engine and fuel injectors, but it really helps everything.

I do this on each car once per year....when we sold our 993 with 198,000 miles on it, it had never had a rebuild, and still had perfect compression, passed emissions, and burned no oil. Same with our 3.2 in Huey, and the 190,000 mile engine on our Tahoe that runs perfectly.

Just a good inexpensive maintenance trick/idea...and it may help clean out some of what's in your carbs. But JP is right, it may be time for a carb cleaning/rebuild.

Congrats on getting it running!