Check Engine light comes on on hard accelleration

[shovel]

Have you ruled out a fuel filter or fuel pump issue?

 

[maillemaker]

Have you ruled out a fuel filter or fuel pump issue?

I replaced the fuel filter and fuel pump about 3 months ago. Fuel pump was not holding prime.

 

[maillemaker]

Well, replaced the O2 sensors, no change. STill getting:
181 - Right side still lean, at richest adaptive limit, during part throttle
189 - Left side still lean, at richest adaptive limit, during part throttle

Time to break out the smoke can again.

 

[maillemaker]

Smoke can revealed a smoking EGR valve, so I figured the diaphragm was torn.

Replaced EGR valve and I'm still getting the same codes. 111 on KOEO and KOER but stored codes are still 181 and 189. Check engine comes on at moderate, lugging acceleration. Goes off when cruising.

 

[maillemaker]

I also ran the Cylinder Balance Test. Came up with a code 90 - all cylinders contributing. Thought maybe some bad injectors but looks like not.

Back to chasing vacuum leaks.

 

[shovel]

Have you ruled out degraded injector wiring insulation? They're all at about that age...

 

[maillemaker]

I have not, but since the Cylinder Balance Test came out OK I'm guessing all are firing OK. I also put my automotive stethoscope on every one I could reach and they are all ticking merrily along. I can reach them all on the passenger side and 2 on the driver's side. Can't reach the back 2 on the driver's side due to the upper intake manifold. Since I'm getting a lean code left and right, I'd have to have bad injectors left and right.

I pulled the MAF sensor tonight and bought some MAF cleaner and hosed it down. Cleared codes and went for a test drive. The CEL came on shortly after I left the house, but I could never get it to come on again. Hopefully the computer was just re-learning the cleaned-up MAF sensor.

We'll see what it does tomorrow heading into the office.

 

[maillemaker]

No CEL today on the drive into work. Maybe got lucky with a simple cleaning of the MAF.

 

[ttocs]

well that isn't new wiring, and I have seen worse but that isn't to say it looks great either. Short of measuring the resistance of the ground wire in the injector I am not really sure what to say and I am not sure what it should measure at to say if its good or bad. The only other way I can think of to test it is to swap out a new injector harness which will not be cheap/easy and you might still have the problem

Have we tried a simple noid light to see if it is getting a pulse, let alone how bright it lights up? You can borrow/rent them at vatozone and it only takes a second.

 

[maillemaker]

The injector picture is from someone else offering a suggestion. I assume my injectors are fine as I passed the Cylinder Balance Test with flying colors.

I'm still getting the CEL, but not as often.

I'm going to plug the intake ahead of the MAF for the next smoke test. I've been disconnecting the flex hose and putting a nitrile glove over the aluminum throttle body opening. Maybe the leak is upstream in the flex hose or something.

I pinched off the vacuum line running into the driver's fender for the cruise control. CEL still came on (and I had no cruise control, so my pinch-off worked), so I can rule out a vacuum leak on the cruise control circuit.

Steve