O.K. I am crying UNCLE!.
I thought I was a smart cookie and could figure this out myself. I am what I would consider a pretty good mechanic but this one has got me stumped.
Here is the story.
Purchased an 87 notchie with a 2.5L and a 5 speed about a month ago. P.O. said it was low compression on #1 cylinder. He had replaced the engine a few years ago for the same thing. He was driving around with the new engine installed and heard a pop and low and behold no power. The “new” engine is a used engine form do not know where. It is a DIS engine and appears to be correct for this application. I even got the old engine in the deal. Looks like he swapped them out completely. The manifolds, sensors and ignition system are still on the old engine.
Here is the problem. It starts and idles very smooth when cold and starts to idle rougher as it warms up. Not bad but does rock around a bit. When you try to drive it there is no get up and go. It is very sluggish. The car will go 70 MPH plus but you won’t be getting there very fast.
Here is what I have done. Changed out plugs and wires. P.O. had some kind of wiz bang super duper wires and those 4 electrode plugs. I installed regular plugs and stock replacement wires. The old plugs looked pretty good though. The end plugs #1 and #4 looked very good I would say almost on the lean side. The two center plugs #2 and #3 looked a little less than stellar but acceptable maybe a little rich.
Checked fuel pressure and it looks good 10 PSI. Even changed the filter.
Compression is between 160 and 170 on all cylinders.
Good steady vacuum at idle and at 2000 RPM with no drop from idle.
Went to exhaust shop and they were certain a plugged CAT was the problem. Had it replaced and then they decided I may have another problem. Yeah, the new CAT didn’t fix the problem.
No codes in the computer.
Throttle opens all the way with the gas peddle.
Swapped out the MAP sensor with another one I had. Don’t know if it is good or bad but made no difference.
Brakes are not dragging.
When it idles the exhaust smells rich.
I plug in my scan tool and can see the O2 sensor switching between lean and rich with engine running at 2000 RPM.
The Injector does not seem to be leaking.
Alright folks, I need help.
[This message has been edited by RCW (edited 05-05-2008).]