Hard to start when warm

[lneidlinger]

I've had this problem for a while now. It's starting to bug me though. Basically, if the truck has been sitting for 8-10 hours, enough to sufficiently cool off the engine, it will start in 1-2 cranks no problem. Once it gets warm and you shut it off and restart it within 5 minutes, it fires right up.

But...let it sit for 10mins to about 8 hours, and it will sit there and crank 10 or 12 times before it finally starts, it typically shoots a bit of black smoke out the exhaust, and when it finally does start it idles down around 550rpm for a couple of seconds then comes up to about 750rpm. I know the coolant temp sensor for the gauge went bad and I had to replace that (that made me think I had a cracked head) so could it be the coolant temp sensor that feeds the computer has also failed? I believe the IAC valve is going bad, as on the really cold days in the winter it would make the infamous foghorn sound until the engine got up to temp.

 

[bhawk]

We battled a no start condition (when warm, sometimes when hot) on our 94 ranger 4.0. Eventually I changed the engine coolant temp sensor (the one that feeds the computer, not the guage) and that fixed the problem. For the price, about 20 bucks, I would buy the best quality sensor you can find and try it. Don't buy the all plastic one, get the brass one. If that sensor does not send the right signals to the computer, it fouls up your starting. The new plastic sensor apparently lasted only 2 years for us. Replaced with an old brass one off a wrecked truck, and it worked fine.

 

[larz0001]

ive got a 95 4.0 thats doing the same thing, i just got off the phone ordering a new temp sensor and gonna install it tomorrow , will let everyone know if the problem is fixed

 

[larz0001]

well i wont be getting anything done today its pissing down rain like crazy, damn working outside sukks

 

[larz0001]

well the weather is finally better here today, i swapped out the temp sensor and holly crap the truck starts every time now. i took it for a short drive and even the throttel response seems better idk mabee its just me being excited about being able to drive my truck again, lol i hope this will help anyone else having this trouble