Truck starts cold. Won't when warmed up??

[Mazdakidd]

On my 94 b4000 I can start it up fine when it is cold. But as soon as it warms up it will turn over but not start. I have to leave it sit for about 45 minutes before it will start again. I have changed my plugs, wires, and fuel filter. I also had autozone test my ICM. And it passed. Could it be my fuel pump / strainer? How can I check? I don't know what else to check. Help???

 

[disciplerocks]

Coolant temp sensor. The 2 wire one, not the single wire.

Or it could be the ECU. Mine was the ECU, but the coolant sensor is more likely.

 

[infantry grunt]

this happend to a friend of mine once,turned out their was a wire that was touching the manifold.when the engine was cold it ran fine,when it warmed up,the coating on the wire would melt grounding the ignition,when it cooled off the wire coating hardened and kept it from grounding till he cranked it back up again.just a thought,you might want to check all wires around anything that gets hot and zip tie and replace if needed.hope this helps

 

[Mazdakidd]

Coolant temp sensor. The 2 wire one, not the single wire.

Or it could be the ECU. Mine was the ECU, but the coolant sensor is more likely.

Where do I find the sensor at? Do you know? I'll defiantly check that out for sure!

 

[disciplerocks]

Should be right in front by the thermostat. Assuming you also have a 4.0.

 

[Mazdakidd]

Yeah I do have the 4.0 they are a pretty cheap! But I also just remembered that my engine gets really hot then cools way down so it goes to like 3/4 of the way up the gauge them drops when I hit the gas to about 1/4. Maybe that could be the issue????

 

[docsimon]

giving reply

hello dangerranger83,
I thought you are right.