91 Explorer stalling/shutting off
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91 Explorer stalling/shutting off
My 91 Explorer has recently started stalling and shutting off when I let off the gas pedal. It is also missing and pinging a little. I have recently changed the fuel filter, fuel relay, and I cleaned the IAC which had lots of carbon build up. I have also ran fuel injector cleaner through the system as well. My last tune up was about 5 months ago, but I checked my spark plugs and they didnt have a lot of build up on them so I didnt expect them to be the cause of the stalling/shutting off though they may be causing the miss. What's driving me bananas is that some days it'll run fine with no stalls and some days it stalls and shuts off at every stop. I noticed that the fuel pump seems to run for a very long time after the vehilcle is turned off. (sometimes up to 20 minutes) My engine light has never came on and on the days that it runs, it seems to run rather well. I was about to take it somewhere to have it diagnosed, but I wanted to know if anyone could provide any suggestions. Paleeeeeeeeze help me!! Thanks!
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From: Cincinnati
Could be many things
I had some of those problems because of a sticking fuel pressure regulator. Easy to replace and about $80. You could monitor the fuel pump current by removing the fuse. That would tell you if it was something in the fuel system, wiring, relay, regulator, or motor. Some have reported problems with relay ($10). Mostly you will have to guess and replace a lot of parts. Until it fails, all measurments will be normal. It took over a year to solve my problem.
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Thanks for your speedy response OHW!! Question: How exactly do I monitor the fuel pump current after removing the fuse and how can I tell if its the wiring, regulator, or motor? Had you replaced your fuel pump before you realized it was the fuel regulator?
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From: Cincinnati
Look at the end of this thread for details.
https://www.ford-trucks.com/forums/s...9&goto=newpost
My problem started when I put in a new pump. It tales a lot of effort to actually prove what is happening. Knowing it is the fuel system is a major step. I monitored the current which went down and the voltage at the pump which went up. I tried two pumps, so it wasn't that.
https://www.ford-trucks.com/forums/s...9&goto=newpost
My problem started when I put in a new pump. It tales a lot of effort to actually prove what is happening. Knowing it is the fuel system is a major step. I monitored the current which went down and the voltage at the pump which went up. I tried two pumps, so it wasn't that.
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You mentioned monitoring the current by removing the fuse. When I remove the fuse and try to start, I get nothing at all. Also, with the fuse in, the pump is not shutting itself off. It appears to be humming all day long and over night whether the truck is on or off.
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Ok, I just looked at your last reply a little closer and the answer is "no" I didnt place a current meter in place of the fuse. What should the meter read when I do this? Why is the pump never turning off? What could be causing it to continuosly hum even with the truck turned off? Thanks in advance OHW!
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Elder User
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From: Cincinnati
Fuel pump relay
is connected to power all the time. If the contacts stick, the pump will continue to run. This sticking is because the contacts weld from heating. Heating is caused by excessive currents or resistance in the contacts. For $10 you can get another relay or switch this one with another non critcal one (not ECM or headlight). At the time you pull the relay, make sure the socket contacts are properly seated. As to current read the referenced post.
The darn relay!!
