90 240 Running rich

[AJS]

Running really rich and hot. O2 sensor is fine (had replaced a few months
ago and both new and old don't solve the issue). Fuel pressure is fine.
Injector noise has increased. Checked AFM connections and temp sender
connections.
No codes. What's next?



AJS

 

[User]

Running really rich and hot. O2 sensor is fine (had replaced a few months
ago and both new and old don't solve the issue). Fuel pressure is fine.
Injector noise has increased. Checked AFM connections and temp sender
connections.
No codes. What's next?



AJS

If the engine is running very hot the fuel injection goes full rich to
with full advance to protect the motor. Why is the motor running hot? No
coolant? Low coolant? Head gasket leaking? Restricted radiator? Bad fan
clutch?

Bob

 

[AJS]

If the engine is running very hot the fuel injection goes full rich to
with full advance to protect the motor.

It's seems to be running rich and THEN hot. So rich from idle on a cold
motor.

Why is the motor running hot?

Well that's the thing. Symptom or cause? Thermostat seems to be working
correctly but will be replaced anyway..

No coolant? Low coolant?

Coolant is fine. I flushed and replaced when these symptoms occurred just to
be certain.

Head gasket leaking? Restricted radiator? Bad fan
clutch?

Nope.



AJS

 

[AND Books]

:
:> If the engine is running very hot the fuel injection goes full rich to
:> with full advance to protect the motor.

: It's seems to be running rich and THEN hot. So rich from idle on a cold
: motor.


:>Why is the motor running hot?

: Well that's the thing. Symptom or cause? Thermostat seems to be working
: correctly but will be replaced anyway..


:> No coolant? Low coolant?

: Coolant is fine. I flushed and replaced when these symptoms occurred just to
: be certain.


:>Head gasket leaking? Restricted radiator? Bad fan
:> clutch?

: Nope.



: AJS


may be a ridiculous idea, but check the distributor cap. a crack may
misfire on one-of-four (always or intermitently)... causing overheating
an apparent rich-mix... it happened to me once... it was real puzzler
btw. it the catalytic converter also running hot? that's a hint...



--

 

[AJS]

may be a ridiculous idea, but check the distributor cap. a crack may
misfire on one-of-four (always or intermitently)... causing overheating
an apparent rich-mix... it happened to me once... it was real puzzler
btw. it the catalytic converter also running hot? that's a hint...

There is no doubt it's running rich the best I can get is 350Km's from a
tank VS getting 450 with hard driving.



AJS