Hot restart issue

[tpa5]

After driving the truck and parking it hot if I try to restart it after 10-15 minutes the idle is bad. If I put it in gear and drive it it smooths out but usually about a mile later it wants to die. If I let it cool it runs fine again. It has 203k and I have tried the fuel filter and coil. Been reading about the intake manifold gasket leaks. Not sure if that could be it. What parts are really susceptible to heat soaking? The IAC measured 10.6 ohms, my book say 6-10 ohms, is that close enough? How hard is it to change the fuel pump?

 

[RonD]

Do you see any blue smoke from the exhaust when restarting hot, hot oil is thinner so it can leak pass valve seals easier.

There are 2 sensors that detect engine heat and set fuel mixture, one is an engine coolant temp sensor, the other an intake air temp sensor, either of these could be acting up and telling the engine control module engine is cold at restart and so it runs rich which causes missing at restart.
How are cold starts and cold running?

 

[tpa5]

Runs fine when cold. Didn't see any smoke but will look. Can these temp sensors be easily checked with an ohm meter? What kind of readings should I expect?

 

[tpa5]

I didn't see any smoke. I measured 2 temp sensors. One in the air snorkel and one in lower intake. They seemed good. Air snorkel was 18k then rose some when I put it in front of a fan. The one in the intake was 3.29k with the motor hot. Speaking of hot the motor seemed very hot. The dash gauge was in its normal spot. I don't really trust the dash gauges but that's all I have. I cleaned the MAF with crc spray. Waiting with the battery disconnect now.

 

[tpa5]

Finally found an autozone with a loaner fuel pressure gauge. Ran and got it while the truck is cooling down. With engine not running and after cycling key three times it was only 31 psi. Then when I started it dropped to 28. Dropped three pounds so maybe regulator is ok. Pressure and drop seem to both be on the low side from what I have read. This was with engine cold. In the morning after I drive to work I am going to test again. Any thoughts at this point?

 

[tpa5]

Was able to measure fuel pressure while truck was acting up. Same pressure reading as before. What else could it be? PCM? Can I use an Explorer same year, engine, tranny and 2 WD like mine?

 

[tpa5]

Well an explorer computer will work in a ranger, I just tried it. Now I have to wait and see if it fixes the hot soak issue.

 

[tpa5]

The PCM did not fix it. I could also tell a bit of difference in shifting so I put the original back. Any ideas?