CEL Code Help

[84bluebronco2]

94 Explorer XLT, 4.0, M5OD, BW1354M

Got around to pulling my codes today. Truck runs, but choppy under hard throttle (3k area and higher), and smells incredibly rich.

KOEO:

337 - EGR position sensor above max voltage

Continuous Memory:

181 - Adaptive fuel limit reached part throttle right side
186 - Injector pulse width longer than expected
211 - Profile ignition pickup circuit fault
332 - EGR valve not opening detected
337 - EGR position sensor above max voltage
528 - Clutch pedal position circuit failure

KOER:

337 - EGR position sensor above max voltage


By process of elimination I can tell I have EGR issues, but I'm a little lost on the PIP code, injector pulse width, and adaptive fuel limit codes. Any insight would be great.

Thanks everyone!

 

[SenorNoob]

Code 211: "Two or more successive erratic Profile Ignition Pickup (PIP) pulses occurred, resulting in a possible engine miss or stall." - OldFuelInjection.com

That's a little more descriptive than your source.^
Also: http://www.explorerforum.com/...
Probably means that the engine is missing because of the rich running.

Adaptive fuel limit code means that the computer has set the injectors to (in this case) maximum duty cycle (more or less open all the time) and the problem still exists.

That's why it's running the way it is. Question is: Why did the computer do that? Maybe it's all because of the EGR being messed up?

Hopefully someone who understands the EGR logic better can help you more.

 

[84bluebronco2]

Guess that means it's time to do some PIP research and see how when and where it comes into play. The truck will stutter and stall on the first start 75% of the time, but start fine right after. Probably pinched something putting the heads back on... thanks SenorNoob


Can't rep from my phone... but a sincere +1 to you sir.

 

[SenorNoob]

Your welcome.

I just had another thought on this one: That code 181 would make me think that the o2 sensor is reporting a lean condition. If it is and the trucks running rich - I'd look at the wires to that right side o2 sensor first. If it got pinched under the head on that side then the signal from it would be grounded (to the block) and would definitely be reading low voltage (IE:0). Which is a lean condition.

From the routing it wouldn't be hard for those wires to get caught under a head.

Edit: Another thought. Since you have a code for only one side and a 94 has two o2 sensors: The EGR and the PIP should affect both of them. If my understanding of that is right PIP comes from one of the engine position sensors (Camshaft Position or Crankshaft Position). But it seems like basically it's saying that the engine is running rough enough cause an uneven rate of rotation at one of those sensors.

 

[PetesPonies]

Yes, on engines with distributors, then PIP is generated at the stator in the distributor. But on engines that are distributorless, it is at the crank sensor. That being said, just because you have a PIP code doesn't mean the crank sensor is bad. Sometime in the past a PIP signal could have been missed because the engine stopped for some other reason . . . possibly. You should clear your codes and run it to generate more recent codes. Your computer thinks the engine is lean and is richening it up past where the computer thinks it should have to do. But with no O2 codes, it probably ( no promise ) isn't your O2 causing it. I would lean towards a vacuum leak possibly. But clear them first, then check for leaks. Spray some carb cleaners all around your intake manifold and such.

 

[RonD]

The EGR system is only used when engine is under load, so accelerating, going uphill, pulling a load, ect....
It is there for lowering emission but it also cools the cylinders preventing pinging/knocking.

The computer is setup for the exhaust gas coming in under load and adjusts the fuel/air mix accordingly, if there is no exhaust gas coming in then the mix will be wrong.

Yes, first stop on your repair should be to get the EGR system working.

EGR Valve can be cleaned and tested, just put a vacuum line on it and suck on the line, valve should open easily and then close(all the way) when vacuum is released.
EGR tube/pipe can often get plugged with carbon, make sure it is clean, also check the intake manifold port for the EGR valve make sure is is clean.
The '94 4.0l should use an EGR solenoid, it is a small black plastic unit that will have 2 vacuum lines(one from the EGR valve) and an electrical connector.
The computer activates this solenoid to open the EGR valve, make sure there are no leaks in the lines or the plastic case.
You can test the electrical part by giving it 12volts/ground, it should click when it opens and if you are applying a vacuum to one port vacuum should pass to the other port.

EGR position sensor, not sure what the '94 used, but read here:
http://oldfuelinjection.com/index.php?p=35


Profile Ignition Pickup (PIP), have a read here:
http://oldfuelinjection.com/?p=25

I think the others are correct that this code was set by mis-fires and is not a "cause" but an "effect" issue.
And yes the DIS(no-distributor) system uses the CKP(crank position) sensor to get the PIP, if the CKP sensor fails engine will not start, the computer doesn't know the crank is turning, so no spark or fuel, if no CKP pulse