95 3.0L running rich after overhaul

[renegade295]

I have a specific issue that I havent been able to find in past post.

I had a bad injector on the right back of my 95 villager. Figured if I was going that deep I would go ahead and rework the heads and replaces gaskets and timming belt. Everything went well until final re-assembly. Started right up but would not accelerate, seemed to checked out perfect. Then I noticed that in my haste I reversed the plugs for the TP and MAF. After switching back it would not idle but reved perfect. Assumming I damaged the MAF or TP I replaced both.

The T/P was used but the MAF is new. Doesnt set the light but after taking for a 5 mile drive it set the MAF code again. But no light and no other codes.

Still will not idle and blows black smoke on acceleration. ( running very rich ) If I unplug the MAF it idles perfect but obvioulsy stalls on acceleration. I also verified there is no vacum leak.

Also during the 5 mile drive the van shifted very late and very harsh, wich is why I am wondering if the junk yard T/P sensor is bad.

Could the T/P be bad and not set a code? Could I have damaged the ECM?

Or did I miss something else along the way?

Any help would be greatly appreciated.

[tempfixit]

I would double check the TPS. What did you set your timing at? I believe it should be 17 degrees.

[renegade295]

Problem solved.

I was leaning toward the T/P, but wasnt positive. So I found the post giving directions on downloading the nissan service manual. I downloaded on my laptop and then went out and start checking voltage and resistance on everything.

The only abnormal thing I found was low input voltage on the hard stop T/P. So, on a hunch I called around and found a used ECM. $30.00 After installing the ECM the van is running perfect.

I obviously damaged the original ECM by reversing the T/P and MAF plugs. Which makes sense after I went through the test procedure for both components. the T/P has a 5volt input, while the MAF has a 12 volt input. And the MAF's 12 volt input is in the same plug pin as the T/P's return signal position. So sending 12 volt back to the ECM in place of a 5 volt max return signal probably isnt a wise choice.

Any, problem solved and van is running great now.