diagnostic help needed
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Freshman User
Joined: Dec 2006
Posts: 37
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I just wanted to update on my suspected fuel pump stalling/cool down/re-starting issue. Since I last posted on this, I have stalled twice more with the engine warm, and as before, the immediate restart attempts failed (symbolic of 0 fuel getting to the engine).
And in like all the previous cases -- after anywhere from 10-30 minutes it starts back up.
However, on the last stall, yesterday, I decided to hook up my test fuel GAUGE as I finally had the time to do this. And as suspected, there was NO FUEL PRESSURE, none, in the key on, or in the crank mode.
After waiting 20 minutes it started right up again. So I checked the gauge to see what the operating pressure was and it had a reading between 30-35 psi. (seems low)
I guess I will have the fuel pump replaced after all, as I think I have pretty much exhausted this diagnosis.
Thanks to everyone on this forum that responded. good luck to all.
mh
And in like all the previous cases -- after anywhere from 10-30 minutes it starts back up.
However, on the last stall, yesterday, I decided to hook up my test fuel GAUGE as I finally had the time to do this. And as suspected, there was NO FUEL PRESSURE, none, in the key on, or in the crank mode.
After waiting 20 minutes it started right up again. So I checked the gauge to see what the operating pressure was and it had a reading between 30-35 psi. (seems low)
I guess I will have the fuel pump replaced after all, as I think I have pretty much exhausted this diagnosis.
Thanks to everyone on this forum that responded. good luck to all.
mh
Lead Driver
Joined: Sep 2006
Posts: 7,907
Likes: 143
There are three major possibilities for faults.
The relay that closes power thru to the pump has burnt contacts.
The pump opens it's intenal cut-out and resets sometime later.
The crash sensor is faulty or wiring.
FYI, key on only starts a 1 or 2 second timer in the PCM to alow the pump to pre charge the fuel rails.
After that, cranking signal from the crank sensor restarts the pump thru the same PCM control.
Now you have enough info the look at the parts of the circuit for failure before taking very much apart needlessly.
Good luck.
The relay that closes power thru to the pump has burnt contacts.
The pump opens it's intenal cut-out and resets sometime later.
The crash sensor is faulty or wiring.
FYI, key on only starts a 1 or 2 second timer in the PCM to alow the pump to pre charge the fuel rails.
After that, cranking signal from the crank sensor restarts the pump thru the same PCM control.
Now you have enough info the look at the parts of the circuit for failure before taking very much apart needlessly.
Good luck.
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Freshman User
Joined: Dec 2006
Posts: 37
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Thanks Bluegrass,
I ruled out the relay and the crash sensor would be a long shot given the thermal dynamic involved with the stall and start-up, therfore pretty confident it's the fuel pump -- something the fuel test gauge had seemed to confirm as well.
If it turns out to be something else, Ill be sure to come back and include it here.
regards
I ruled out the relay and the crash sensor would be a long shot given the thermal dynamic involved with the stall and start-up, therfore pretty confident it's the fuel pump -- something the fuel test gauge had seemed to confirm as well.
If it turns out to be something else, Ill be sure to come back and include it here.
regards
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