OK here is my problem. My 93 SC400 will not start after reaching running temp. When the car is cold it starts right up and runs great. However if I stop the car (like to get gas) it will start rev then immediately die. No matter what I do, like trying to rev it to keep it going it dies. If I let the car sit and cool maybe 45 minutes it will crank right up and idle. I did replace the TPS about 2 months ago because of idle issues that seem to fix the problem. I also cleaned the IAC valve.

Any ideas?

 

Fuel filter, fuel pump, or fuel pump ECU. could be any of those 3.

 

That can be a lot of things... maybe a bad coolant temperature sensor ? That sensor tells the ECU if engine is hot or cold. On hot-start , the ecu readjusts ignition timing and activates fuel pressure vsv which controls FPR.

 

Coolant temp sensor. It does seem like something is shutting off the injectors. / fuel supply. When hot the car cranks and initially revs to about 1200 rpm then it's like the fuel gets shutoff.

Fuel Pump, Fuel Filter, Fuel. ECU. Why would these not work when the car is hot.

Also if I crank the car cold it will drive great literally forever it is only the restart that fails

 

I am with you on the fuel pump,filter and fuel. It seems to me if they were an issue it would happen cold and hot. I would also agree that something is shutting off the injectors. I think you are on the right trail with the coolant temp sensor

 

So basically The car will run fine as long as its cold. But if it's hot then it turns off?

If so I think it's the coolant sensor. It's an easy change.

 

I believe it's a coil issue. I would check for spark once it gets hot

 

Actually it will run fine when it is hot just can't crank it hot

 

Something is allowing the injectors to work for a few seconds then shut off OR something is shutting off the ignition source after a few seconds.....can't imagine what would do that either. Now that I think about it no matter what the coolant temp sensor said it would not shut off the injectors would it??

 

I agree with Ihiryu then. Check the spark

 

Does the check engine light come on during this time? Like when it's hot, and you turn the key to the ON position does the light come on for a few seconds then shuts off?

 

Nope, no CEL and no codes.
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I did replace the coolant temp sensor but that didn't fix it

Car runs fine while it's hot. It just will not restart while it is hot (running temp). It seems that if it was a coil issue it would miss or shut down while it is running

 

any update on your progress?

 

Similar problem for me fixed by bypassing fuel ECU and using the remote antenna as a turn on for the fuel pump.

 

hows your thermostat?