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CEG'er
I know this isn't our platform but I know there are a lot of people here that know the 3L duratecs and I need help.
The motor is in our 2001 escape, 150,xxx miles in decent shape, just used a little oil through the heads. We developed a miss a while back and cannot get it worked out. It's not throwing a code. When it first happened it clogged up the front pre-cat enough that it wouldn't pull itself. We pulled and gutted all the cats so the miss wouldn't wipe them out again. The miss seems to be on the front bank of the motor. I can unplug the coil on plug 4 and 6 and the motor doesn't change how it runs. If I unplug 5 it backfires in the exhaust pretty good. Pulled the valve cover and the cams looked ok as for timing. It starts hard like the timing is out on an old carbed car. It will often want to backfire and buck when it starts. We changed out the cam and crank position sensors and nothing. Decided to pull the heads and get them worked and get all new timing components also hoping there was something wrong with the valves. After a valve job and new guides nothing was found wrong in the heads. The cylinders looked fine still showing the cross hatching also. Re-assembled it and its still doing the same thing. I've done 3 duratecs now so I know the timing chains are right. We also picked up another "good" used computer and had it flashed and nothing changed. I'm at a loss with this thing. Someone said it could be in the pvc system, knock sensor, or that the coolant temp sensor could cause it to change the timing to make it run cooler??? I'm tired of trying things and I'm out of things to diagnose. Cannot tell if its missing on the back bank because of the manifold being in the way and the rear cat was fine when we pulled it so I'm assuming its not. All help or advise is greatly appreciated.
The motor is in our 2001 escape, 150,xxx miles in decent shape, just used a little oil through the heads. We developed a miss a while back and cannot get it worked out. It's not throwing a code. When it first happened it clogged up the front pre-cat enough that it wouldn't pull itself. We pulled and gutted all the cats so the miss wouldn't wipe them out again. The miss seems to be on the front bank of the motor. I can unplug the coil on plug 4 and 6 and the motor doesn't change how it runs. If I unplug 5 it backfires in the exhaust pretty good. Pulled the valve cover and the cams looked ok as for timing. It starts hard like the timing is out on an old carbed car. It will often want to backfire and buck when it starts. We changed out the cam and crank position sensors and nothing. Decided to pull the heads and get them worked and get all new timing components also hoping there was something wrong with the valves. After a valve job and new guides nothing was found wrong in the heads. The cylinders looked fine still showing the cross hatching also. Re-assembled it and its still doing the same thing. I've done 3 duratecs now so I know the timing chains are right. We also picked up another "good" used computer and had it flashed and nothing changed. I'm at a loss with this thing. Someone said it could be in the pvc system, knock sensor, or that the coolant temp sensor could cause it to change the timing to make it run cooler??? I'm tired of trying things and I'm out of things to diagnose. Cannot tell if its missing on the back bank because of the manifold being in the way and the rear cat was fine when we pulled it so I'm assuming its not. All help or advise is greatly appreciated.