1996 Ranger 4.0 p1152 and p1132

[mlevenha]

My dad has this Ranger and I'm trying to help him out with it. We've fixed several issues but nothing we replaced or fixed has changed that it's running extremely rich.

Intake air temp and coolant temp sensors are reading correctly. We replaced the camshaft sensor because it had broken apart internally. He replaced the thermostat because it wasn't getting up to temp, and now it is.

The MAF sensor is reading correct. At 1k rpm it's reading 8 g/s and it's reading 17 g/s at 2k rpm. Both front O2 sensors are reading basically 0.9V because it's running so rich. He replaced them as well and the issue remains.

Something is preventing it from entering closed loop. When I pull up live data it always just says OL-fault. The codes that have always persisted are p1152 and p1132 which are basically saying both banks oxygen sensors are stuck rich. It's not a stuck open injector because the rail holds pressure after shutting off the engine. Whatever the problem is, it affects both banks.

I checked for fuel in the FPR vacuum line and it was dry. Dad put new spark plugs and wires in it. We are both so tired of working on this piece of junk, we've fixed so many issues with it and this still persists.

What am I missing?

 

[mlevenha]

No possible ideas?

 

[SenorNoob]

Any chance someone has changed injectors before and put in larger than stock?
How's the wiring around the injectors, O2 sensors, and PCM look?

That's all I can come up with for now.

 

[mlevenha]

Any chance someone has changed injectors before and put in larger than stock?
How's the wiring around the injectors, O2 sensors, and PCM look?

That's all I can come up with for now.

Hey, thanks for the reply. We looked at the injectors when the intake was off for getting at the cam position sensor, they looked old/original. I haven't seen anything to indicate wiring problems. Good readings from all the sensors in question leads me to believe the wiring is intact. I'm currently considering the possibility that the oil got diluted with gas from running rich, so once we fixed whatever caused the initial problem, it continued to run rich from the fuel in the oil. Going to check that shortly.

 

[SenorNoob]

There shouldn't be that much oil getting into the cylinders. I suppose it it were diluted enough. And maybe has a weak PCV valve.

 

[mlevenha]

There shouldn't be that much oil getting into the cylinders. I suppose it it were diluted enough. And maybe has a weak PCV valve.

I checked it, the oil is super diluted and runny, it smells strongly of gas. Showing quite a bit above the full mark. Hopefully an oil change will solve it this time.

 

[mlevenha]

Oil change didn't help, last ditch effort was a PCM from a junkyard. That solved it. Still seems to have a vacuum leak somewhere because the fuel trims are at around 10% at idle and close to 0% with throttle, but that's minor. Having trouble communicating with the ABS module on Forscan. The light comes on the dash for an ABS error but can't scan it.