Car will not start when warm

[procharlie]

I have two TTAs, one good, other not so good. The not so good one has a problem in that it will start and run OK, but after running to get it up to temperature and stopping it, then it will not start until it cools down. It will crank, but appears to not get ignition. I have switched the ignition modules with my other car, but that didn't change things, and I do have fuel pressure. I think I heard there is a relay under the car that controls ignition signal - could this be the problem? Does anyone know where it is?

 

[procharlie]

I forgot to say that once when I was trying to find the problem, I warmed up the car, stopped it, and when it wouldn't start again I took a water hose and sprayed the engine for a minute or so, and it then would start. So there is something around the exterior of the engine that is causing the problem.

 

[TTA_PACE_CAR]

Normally a no hot start would be the starter solenoid but you say that it still cranks over.

I would check for spark when you are getting this issue, if that checks out ok connect a fuel pressure gauge to the fuel rail and check the pressure.

Fuel pressure should be around 40psi when you turn the key to the on position and steady when running. Also when you turn the car off the pressure shouldn’t drop to zero immediately.

 

[robert lee]

do you have a fuel pressure gauge? Also i would not recommend spraying a hot eng with cold water.

 

[funboy]

I have two TTAs, one good, other not so good. The not so good one has a problem in that it will start and run OK, but after running to get it up to temperature and stopping it, then it will not start until it cools down. It will crank, but appears to not get ignition. I have switched the ignition modules with my other car, but that didn't change things, and I do have fuel pressure. I think I heard there is a relay under the car that controls ignition signal - could this be the problem? Does anyone know where it is?

Try unplugging coolant temperature sensor when it won’t start. If it starts with sensor unplugged I may know whats wrong with it.

 

[procharlie]

I'll try that, and let you know what results. Thanks for the tip.

 

[procharlie]

Can you tell me where the temp sensor is located? I have seen conversations about it and there appears to be two sensors on front of intake manifold, one with one green wire and the other with two wires. Do you know which one I should unplug?
Thanks

 

[TTA_PACE_CAR]

Can you tell me where the temp sensor is located? I have seen conversations about it and there appears to be two sensors on front of intake manifold, one with one green wire and the other with two wires. Do you know which one I should unplug?
Thanks

This is from an 87 Buick GN, same engine.