91 Explorer stalling
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91 Explorer stalling
Recently purchased a 1991 Explorer 4WD 4.0 engine. It is now stalling after running for awhile, after it warms up. The vehicle starts fine, but won't shift out of first gear. When I put into gear it drops in first gear or reverse with a jerk. So far I have checked for vacuum leaks - none. changed gasoline filter, MAS airflow sensor, TPS sensor, temp sensor, vehicle does not drop gasoline pressure when it stalls. The only code I can get is a DTC 37 - insufficent RPM decrease during Integrated vehicle speed control test.
Not sure where to go now. thought I would ask here for suggestions. Some suggestions that I have gotten so far are to check the coil pack, ignition sensor, or the CPU. Any other suggestions?? Has anyone else had this type of a problem?
Thanks for any help anyone can give on this matter.
Not sure where to go now. thought I would ask here for suggestions. Some suggestions that I have gotten so far are to check the coil pack, ignition sensor, or the CPU. Any other suggestions?? Has anyone else had this type of a problem?
Thanks for any help anyone can give on this matter.
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I didn't see anywhere where you checked the fuel pump. I've never had this issue with my '91 EX, but it came up quite often with a Ranger I had (same engine and all).
As for the transmission problem, check the shift pins. These are cheap (approx. $50), but you still have to drop the transmission to get to them. If this is the problem, inspect (and possibly replace) your clutch plate while you're in there.
Just my two cents. Hope it helps.
As for the transmission problem, check the shift pins. These are cheap (approx. $50), but you still have to drop the transmission to get to them. If this is the problem, inspect (and possibly replace) your clutch plate while you're in there.
Just my two cents. Hope it helps.
Hotshot
Joined: Oct 2002
Posts: 18,488
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From: The Big, Oregon
I went in circles for a while with a similar problem years back, it turned out someone had adjusted the throttle stop. I had to reset it with a feeler gauge, I want to say it was a .008" feeler gauge between the throttle plate and bore, then it was all fine. People sometimes try to "fix" a stuck or defective idle air controller by adjusting the throttle, which then makes this problem.
The throttle position sensor also has to be set, I don't have the procedure in front of me right now but you have to adjust to get the proper voltage at the signal return wire on the sensor.
Will the transmission go into second if manually shifted there?
The throttle position sensor also has to be set, I don't have the procedure in front of me right now but you have to adjust to get the proper voltage at the signal return wire on the sensor.
Will the transmission go into second if manually shifted there?
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Yes, i did check the fuel pump and it was working and keeping fuel pressure. And No i did not try shifting manually. will check out the rest of your suggestions in a few days and let you know how it went. thanks for the help!
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replaced Idle Air Controller. Yes, I can shift manually. It will not shift from 1st to 2nd in OD, but if I manually shift from 1st to 2nd and then put it in OD then it will shift up and down until I shift down into 1st, then it will not shift back up into 2nd.
bought OBD I tester (because no one in town can do it). codes are:
57-NPS (neutral pressure switch) open circut failure - or- circut failed in neutral position - or - octane adjust service pin installed.
66-MAF sensor - or- VAF (vane air flow sensor) voltage signal too low -or- TOT (transmission oil temp sensor) signal voltage is too low.
77- operator error during dynamic response portion of engine run self-test.
When it starts cold it will idle between 1000 - 800. it will surge up and down, but does not die. It does not run rough. I am rechecking for a vacuum leak.
- Scouter2010.
bought OBD I tester (because no one in town can do it). codes are:
57-NPS (neutral pressure switch) open circut failure - or- circut failed in neutral position - or - octane adjust service pin installed.
66-MAF sensor - or- VAF (vane air flow sensor) voltage signal too low -or- TOT (transmission oil temp sensor) signal voltage is too low.
77- operator error during dynamic response portion of engine run self-test.
When it starts cold it will idle between 1000 - 800. it will surge up and down, but does not die. It does not run rough. I am rechecking for a vacuum leak.
- Scouter2010.
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