Okay, yep checked the coolant level and it is fine. Doesn't overheat at all or seem to, the gauge runs dead center. I have a code reader and it hasn't thrown a single code at all. I agree the tps is ruled out as it drives and runs fine. I just went out and started it and it was cold. Started right up and held the 750 rpm mark dead on. A short drive with the temp gauge hitting normal and it starts but then the rpm dips to just above 500. If I drive a long drive and it get hot (normal hot for a long drive) then the problem is aggrevated and that's when it dies. I think tomorrow since i have the MAF cleaner I will clean the MAF can't hurt. Considering it seems to be a start/idle issue of some sort I can't think of anything else but the IACV or the MAF. I don't know what else could effect it like that unless it is something in a computer somewhere. Could it be an O2 sensor of some kind? I wouldn't think so since it runs once it is started. I guess I could just drive it places and let it sit till it's cold and then go home lol.

 

I don't think an O2 sensor. They throw codes quickly and it would just run rich or lean, not die. I'm glad you aren't getting any codes because the only other thing I could think of was a clogged catalytic converter but you would have had other signs or would hear it popping or see it glowing red.

I really can't imagine anything other than the IACV and I just throw in the MAF because they have voodoo. Be sure to clean the MAF when it is stone cold (before you have turned the key at all in the morning). I think you've homed in on the culprits.

Where in the world are you anyway? Best diagnoses would be borrowing someone else's MAF and IACV for experimentation.

 

If that doesn't do it we will have to think outside of the box. Like maybe a vac line that collapses when it get hot or something equally exotic and hard to figure out.

 

I am in Western NC. I think I am just going to bite the bullet and purchase a new IACV and get a MAF while I am at it. It is 13 years old it can't hurt to replace them lol. Probably take a few days shipping so when I get them and get them installed I will come back and post and let you know what happens. Till then cold vehicles are good things lmao. Thanks Charlie.

 

My local mech happened to be in his shop today. I went down and talked to him and he said run it till it gets nice and hot and bring it in and he will put it on his big computer and see. he said his computer will show exaactly what the MAF and the IACV are doing. Can't hurt to wait a day to order the parts. He is a good mech and I trust his judgement.

 

I like that. I hated the idea of you buying parts solely on my analysis. Please post what you find out.

 

My mech sat in it and watched the rpm's and said yep I should order an IACV. Ordered should be here wed or thurs. I ordered a MAF as well just to cover another base. Will keep you posted

 

Well so much for good intentions lol. Installed an OEM IACV and no change at all. I have a MAF sensor coming but I don't think that will do anything as well. Since it drives fine when running I don't think it's the TPS. It's just so damned odd that it is definately heat related. Same symptoms as before. ECU maybe? Hell Im at a total loss here.

Could it be the CPS? I have read that when they fail sometimes they fail when hot and are fine when they cool off.

 

I'm not sure, but if it's heat related, it kind of sounds like an intake gasket leak. You could try having someone start it up and keep it running for you while you pour some water around the edges of the lower intake manifold. That's how I used to find leaks like that before I got a smoke machine.
Also, you can have a fairly big vacuum leak on startup and not get any trouble codes. This is because the fuel system is in open loop. So the computer isn't running the fuel trims and watching the O2 sensors until it goes into closed loop.

 

This problem is kind of opposite of a CPS. Usually those will work fine until the engine heats up, then it will die. I suppose it's not impossible, no problem is on a Rover. But it really doesn't sound likely.