76 eldo with FI wont stay running when hot

[rlachance]

Hello,
I have a 76 eldo w/FI and on warm days it starts and runs great until I stop for any lenth of time and then restart it runs real rough and stalls, when I feather the gas and get it back on the road the problem goes away. Car has 43k and has fresh fuel filters and a recent tune up. can someone please help me  solve this problem.
Thanks
   

[76eldo]

That car has an old tech analog computer module and two temp sensors in the engine that control the mixture and basically if the car is in choke mode or not.

One of those things can be the cause.

If the injector seals have not yet been changed you need to do this right away.
The fuel is under pressure when the key is on and the old original seals can get brittle and leak causing a bad situation with raw fuel leaking all over a hot engine.  Please get this checked out asap

Brian

[rlachance]

Thanks Brian, they have been changed, being this is a FI car is vapor lock not an option??

[76eldo]

Everything is on the table but vapor lock is unlikely.  The fuel pressure coming through two electric pumps using a return line normally would alleviate vapor lock.  Fuel pressure is one of the possibilities.

Could also be a bad ignition module or the pickup or the coil in the distributor.

It's a process of elimination and you have to be able to duplicate the symptom and diagnose at that time.  Not an easy fix unless you want to throw parts at it until the problem stops.

Brian

[bcroe]

I have a 76 eldo w/FI and on warm days it starts
and runs great until I stop for any lenth of time and then restart it runs real
rough and stalls, when I feather the gas and get it back on the road the problem goes away. Car has 43k and has fresh fuel filters and a recent tune up.

You can check the 2 engine temp sensors, but they are only effective when
the engine is cold.  You likely have a bad MAP sensor (in the ECU); the engine
starts with extra enrichment but then goes too lean after warmup.  Mixture
is controlled by the ECU.  Low fuel pressure (regulator or pumps) can also
cause bad mixture.  On the first album of my PHOTOBUCKET is info on
checking your MAP; the second album is the schematic.  I repair these ECUs,
testing is free if you pay postage. 

     http://s93.photobucket.com/albums/L71/bcroe/

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BRUCE ROE                                  bcroe@juno.com
5719 EAST SKINNER ROAD,     CLC # 14630
STILLMAN VLY, IL    61084-9215     Phone  815 234-8039

[Glenn R. McLeod]

To check the temperature sensors, put one in a freezer for 30 minutes, then check the resistance. It should read somewhere around 800-820 ohms. Then hold it in a pan of boiling water for 5 mins. It should read around 1350-1400 ohms. If either read below 750 ohms or above 1600 ohms, it is defective. Start with the air temp. sensor. Then undo the water temp. sensor and have the air sensor near to hand. When you remove the first, replace it with the second instantly, so that you don't let any air get into the cooling system. The sensors are identical and are interchangeable. They measure temperature only. What they are measuring is of no consequence. The air temp. sensor is for fine tuning only, and doesn't move that much internally, whereas the water temp. sensor moves through the whole scale of resistance readings internally. Therefore, it is usually the water temp. sensor that fails way ahead of the air temp. sensor. If they both check out alright, you might consider the distributor module. When they fail, they don't usually fail in an instant, they usually give you a few days warning. It will stop working, then after about 30 mins., it will suddenly start working again. It is because it can't handle the engine heat any more, and those few minutes of inactivity allows it to cool off enough to start working again. But it won't last long. Another few days and it will fail completely.