This is getting old...
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This is getting old...
I have a 1986 bii 2.9L v6 4x4 and it keeps stalling on me (its an auto) like when i come to stop it will drop very low like 400 or so on the rpms and go back up to like 1200 or keep going down and stall i have replaced the TPS MAP AICV but it will still do it it used to surge but sense i got the new TPS it doesnt but it only has this problem when the truck is hooked up to the map sensor but it runs real smooth and clean but when i un hook the map it runs real ruff but it wont die at all but it smokes its weird any ideas comments anything i am open to all ive been trying to trouble shoot this for the last month or so ive replaced the plugs wires distributor a whole tune up and replaced what ive heard that will cause it so any ideas i would love to hear thank you.
More Turbo
Joined: Mar 2006
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That surging and stalling sounds like the TFI module on the side of the distributor. It
is not a monitored module as far as having fail codes. Many times when one fails the
surging happens when the engine gets to operating temperature. There is a test for
it in the read first section of this thread. These bugs are maddening, but once you
get them chased down, these are pretty good engines.
is not a monitored module as far as having fail codes. Many times when one fails the
surging happens when the engine gets to operating temperature. There is a test for
it in the read first section of this thread. These bugs are maddening, but once you
get them chased down, these are pretty good engines.
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I went to Orielly's and i asked for the TFI module but they couldnt find it or tell me what it was so if someone could post a picture of it and the full name what it does etc that would be great thanks.
More Turbo
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Post Fiend
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> it will drop very low like 400 or so on the rpms and go back up to like 1200
This sounds like a dirty IAC to me. Details about cleaning it are in the Ranger forum. The IAC flicks on and off many times a minute to adjust idle. A defective one will have have a wide range of RPMs to the point of stalling.
A bad TFI on the other hand, will not have the idle bump up to 1200 rpms all by itself. It will just drop the RPMs and die, it will not increase beyond idle RPMs.
Disconnecting the MAP sensor will kill the vehicle, probably because loss of vacuum usually means WOT to the computer. I haven't thought too much about why though, just a guess.
This sounds like a dirty IAC to me. Details about cleaning it are in the Ranger forum. The IAC flicks on and off many times a minute to adjust idle. A defective one will have have a wide range of RPMs to the point of stalling.
A bad TFI on the other hand, will not have the idle bump up to 1200 rpms all by itself. It will just drop the RPMs and die, it will not increase beyond idle RPMs.
Disconnecting the MAP sensor will kill the vehicle, probably because loss of vacuum usually means WOT to the computer. I haven't thought too much about why though, just a guess.
More Turbo
Joined: Mar 2006
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When the TFI is failing, it can go through a period when it will lose output to the coil.
The engine will begin to die, then the TFI functions again. Then the idle corrects. It
can rev up over 1k. I have had 2 TFI modules show this symptom, and with an
automatic transmission, it can be a nightmare in heavy traffic.
The engine will begin to die, then the TFI functions again. Then the idle corrects. It
can rev up over 1k. I have had 2 TFI modules show this symptom, and with an
automatic transmission, it can be a nightmare in heavy traffic.
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