PCM/ECU problem or wiring...
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PCM/ECU problem or wiring...
Back to my hesitation (95 Sport, 4.0L).
I changed the trans fluid and gasket for the pan (another thread).
Noticed when I first turned the key I didn't hear the (new) fuel pump prime the lines.
Then it worked.
One time I could hear the relay (also new) buzzing/clicking...like it was trying to make contact, but not getting enough power to keep it turned on.
Would that likely be be a PCM issue or wiring?
It is intermittent, and has a hesitation.
AFARR
Edited to add...(had to run the kids to the bus stop and was in a rush). Basically, I'm still trying to pin down the hesitation/stutter. Almost like a momentary stall in the engine. Happens when hot, almost always on maintaining speed (light foot on the throttle...doesn't seem to happen on acceleration or deceleration). The Coil, Wires, Plugs, Dist. Cap and Rotor were all replaced. Fuel pump, filter, Fuel Pressure Regulator were replaced...reads 34psi (proper for my year) at the scrader valve. Throttle position sensor and Crank position sensor were replaced. All this didn't correct the hesitation.
The not-priming pump (and clicking relay) are something I just noticed....but may have been going on all along (I happened to be trying to start the cherokee in the garage where it was very quiet, had the seatbelt buckled (no buzz), and the hood open).
The first time I noticed it, I tried cranking the engine....cranked for a while but wouldn't start. Then I pulled the key out...put it back and and got the hum from the fuel pump. Did that twice and it fired right up.
Was able to duplicate the same problem later that day...no hum from the fuel pump. Then after leaving the key in on 'run' for a while (not even cranking the engine), pulling it out and trying it again, got the hum from the fuel pump twice...and it fired right up after that.
Thanks!
AFARR
I changed the trans fluid and gasket for the pan (another thread).
Noticed when I first turned the key I didn't hear the (new) fuel pump prime the lines.
Then it worked.
One time I could hear the relay (also new) buzzing/clicking...like it was trying to make contact, but not getting enough power to keep it turned on.
Would that likely be be a PCM issue or wiring?
It is intermittent, and has a hesitation.
AFARR
Edited to add...(had to run the kids to the bus stop and was in a rush). Basically, I'm still trying to pin down the hesitation/stutter. Almost like a momentary stall in the engine. Happens when hot, almost always on maintaining speed (light foot on the throttle...doesn't seem to happen on acceleration or deceleration). The Coil, Wires, Plugs, Dist. Cap and Rotor were all replaced. Fuel pump, filter, Fuel Pressure Regulator were replaced...reads 34psi (proper for my year) at the scrader valve. Throttle position sensor and Crank position sensor were replaced. All this didn't correct the hesitation.
The not-priming pump (and clicking relay) are something I just noticed....but may have been going on all along (I happened to be trying to start the cherokee in the garage where it was very quiet, had the seatbelt buckled (no buzz), and the hood open).
The first time I noticed it, I tried cranking the engine....cranked for a while but wouldn't start. Then I pulled the key out...put it back and and got the hum from the fuel pump. Did that twice and it fired right up.
Was able to duplicate the same problem later that day...no hum from the fuel pump. Then after leaving the key in on 'run' for a while (not even cranking the engine), pulling it out and trying it again, got the hum from the fuel pump twice...and it fired right up after that.
Thanks!
AFARR
Last edited by AFARR; 09-19-2011 at 07:02 AM. Reason: More Info...
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