I have both pre and post turbo EGT Gauges. The pre-turbo gauge measure both the EGTs at both the front and rear exhaust manifold. Up til last night, I was getting nearly identical readings from the front and rear preturbo gauges. All of a sudden I was getting 200 degree C lower temps from the front gauge. No other symptoms occurred (engine temps normal, performance excellent, no smoke, no noise).

I tried to compile a list of possible problems and would appreciate any suggestions.

1. coolant leak in front chamber ---- Unlikely--no white smoke

2. exhaust manifold gasket leak (sucking air into mainfold) ---- Unlikely--No associated exhaust noise.

3. stuck open injector in front chamber--- unlikely--AFRs are consistent with precondition readings.

4. spark plug failure---unlikely---AFRs and performance are the same as before.

5. EGT sensor bad......will check

6. EGT gauge failure----will check.


TIA for any input.

Jeff

 

it's well known that the rear rotor gets fed more than the front rotor in the fd's, but i don't know why you would notice it "all of a sudden". if you've got an ems in there, just jack up the secondary injectors fuel trim.

 

Actually, it was sudden, previously there had been less than a 15 degree differential.

I have a PFC but I don't think that jacking up the secondaries won't affect the egt differential as it will simply deliver more fuel to the entire system. As far as I know there is no way to individually meter the injection pulses on the system.

 

you can't raise the rear-secondaries only? suck!

 

I would lean towards the EGT probe dying. That location is REALLY hard on EGT probes.

Dale

 

Easy to diagnose.. Just swap the probes.

 

Yup that's the plan for later today.
The plan to test the gauges are to swap the inputs.

 

I am glad to hear you say that....I sure hope so too!!!!