85 gmc siera problems
 

i have an 85 gmc 1500 4x4 and it seems to run fine most of the time, but when the motor gets hot or i have been riding for a while it will cut off. it almost seems like it is running out of gas, but its not, the motor will turn over but will not crank back up. have to wait for motor to cool off and will crank back up. i have replaced the distributor, ignition module, put a msd blaster coil on it, fuel pump, rebuilt the carb, new battery, new starter, im still having the same problem i have been chasing for about 2 years. can someone please help me

Does the truck have a coolant temperature sensor? I know it was around that time when they started putting them in.

85 gmc
 

no it doesnt have a cooland temperature sensor on it.

Not to doubt your knowledge of your truck but are you sure? I see a part number listed for one. The way your truck is acting is exactly what a bad coolant temp sensor acts like. Trust me I got stranded over that little $12.00 bastard.

Duralast / Coolant Temperature Sensor For your 1985 GMC Truck C1500 1/2ton P/U 2WD 5.7L 4BL OHV 8cyl





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Welcome aboard, I'd look into the sensor myself. Sounds like you've already replaced the common stuff, time to think outside the box. Good luck.

Ok thanks I will see if I can find something I couldn't find it in my manual so I figured that it didn't have 1. Now looking at it I believe that it is the one sitting above the thermostats correct?

Yes that is where it would be. Hopefully that is your culprit!

1985 gmc acceleration
 

i dont know it the coolant temperature sensor did anything to help until i see if my truck does it again. the motor has to be running for a little while to running temperature and then iddle for about 5 mins and try to take off the truck starts to spit and sputter kind of like it is running out of fuel. but it is getting gas. then the truck shuts off. the motor will turn over but wont crank, you can smell gas when you open the butterfly gas pumps into the carb. has a weak spark. i just replaced the coil, and the distributor. it has to cool down to about 160degrees and then it will crank but wont get far before the motor heats back up to 190degrees and runs for about 10mins and stalls back out.

I am curious if it does it again...let us know.