Won't start when warm, runs high/rich

[disciplerocks]

Just like it says. Once I drive her for a bit and shut it off, it won't start for about 45-60 minutes. Its also idling high and running pig rich. This is all after my 4.0 swap. I already searched and the only answer I can find is replacing the coolant temp sensor. I already did that and it did nothing.

 

[Duane867]

Iac ?

 

[disciplerocks]

I thought about that, but when the one went out on my Focus, it idled high for a minute, then dropped off. And it always started so I didn't think it was that.

 

[adsm08]

Check the MAF. What year is your donor, I'll get you a test for it.

 

[disciplerocks]

It was a 94. It ran fine before hand. I find it weird that a sensor would quit working while the motor was out.

 

[disciplerocks]

Oh it was an Explorer too. Not sure if anything was different between the Ranger an Ex of the same year.

 

[adsm08]

It was a 94. It ran fine before hand. I find it weird that a sensor would quit working while the motor was out.

Are you kidding? MAF sensors, especially old ones, are very sensitive to vibrations. I broke the MAF on my sister's old car by putting an air filter in because the hot wire was that burnt up. Think light bulb filament.


There are differences between the Ranger and Explorer body harnesses, but they usually make it not run at all rather than just run poorly.




And of course I can't find the freaking component test for it.

 

[disciplerocks]

I got some electronics cleaner around here somewhere. I'll give that a shot.

 

[adsm08]

I'm not thinking it's dirty, I'm thinking it's broken. Problem is, I can't find the test that tells you which pins should have what resistances.

 

[disciplerocks]

Ah ok. Well no hurry on that then. My meter is at work. I'll have to bring it home tomorrow.

Too bad the one on the Focus isn't the same. Injector sizes are pretty close, but it has the built in IAT so the plugs wont match.

 

[adsm08]

Yeah. Go ahead and try cleaning it if you want to. Worst case scenario is that it's broken and clean. Best case, you might actually fix it.

 

[disciplerocks]

K, anything else you can think of that it might be that I can check. IAT or TPS maybe? I think I have a spare IAT.

 

[adsm08]

IAT might do that, but the MAF is more likely to cause a no start.

That thing doesn't have a seperate MAP/BARO sensor does it?

 

[disciplerocks]

That thing doesn't have a seperate MAP/BARO sensor does it?

I tried cleaning the MAF. Started it back up and actually listened. It idles high at first like normal, kicks down like it is supposed to, then about 30 seconds later it kicks back up to a high idle. Didn't let it run long enough to try a warm start.

 

[disciplerocks]

Drove it to work today. Tried restarting after I got here and it wont. If I can get out of work on time on of these days I'll pick up a couple spare MAFs from the u pull. Any chance it could be the computer? I have a 93 Ex computer here too. Not sure if the pinouts are the same from 93-94.