Computer lost & found.
Thread Starter
Drifting
Joined: Aug 2000
Posts: 1,251
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Computer lost & found.
My 84 was running fine then the check engine light came on & it started idling fast.
When I got to my destination I checked for the code.After grounding the connector under dash I didnt get the 12 code.No connection to the computer.
The check engine light was steady on , no flashing.
So on the way home at a stop light the engine suddenly went from 1100 rpm to 600.I thought it was gonna die but actually it went back to its normal self & the check engine light went out.
So I got home & rechecked for codes & the computer gave me the 12 & no codes.
So I guess I lost connection to the computer for a while.
Never happened before,havent been working on anything latley.
Any one want to guess what happened?
Thanks in advance.
When I got to my destination I checked for the code.After grounding the connector under dash I didnt get the 12 code.No connection to the computer.
The check engine light was steady on , no flashing.
So on the way home at a stop light the engine suddenly went from 1100 rpm to 600.I thought it was gonna die but actually it went back to its normal self & the check engine light went out.
So I got home & rechecked for codes & the computer gave me the 12 & no codes.
So I guess I lost connection to the computer for a while.
Never happened before,havent been working on anything latley.
Any one want to guess what happened?
Thanks in advance.
Melting Slicks
Joined: Aug 2001
Posts: 2,516
Likes: 0
From: Lockport NY
Re: Computer lost & found. (nobodyunknown)
My first guess would be a bad ground somewhere. Sounds like it went from closed loop to open loop and back again...(or is it open loop to closed loop and back again?)...
Do you have a spare ECM? That's the 870 ECM, correct?
Do you have a spare ECM? That's the 870 ECM, correct?
Thread Starter
Drifting
Joined: Aug 2000
Posts: 1,251
Likes: 0
Re: Computer lost & found. (Rich B.)
I can only guess that its the original computer.
I've never seen it.
It may never happen again,then again it could start happening a bunch.
If I need a computer dont I want one called a 7447?
Would it need splicing or is it plug & play?
I think its from a 90 pickup But need some refreshing on the subject.
I'll check for loose connections soon.
I cant imagine a ground suddenly comming loose as its been tight for 189,000.
I've never seen it.
It may never happen again,then again it could start happening a bunch.
If I need a computer dont I want one called a 7447?
Would it need splicing or is it plug & play?
I think its from a 90 pickup But need some refreshing on the subject.
I'll check for loose connections soon.
I cant imagine a ground suddenly comming loose as its been tight for 189,000.
Melting Slicks
Joined: Aug 2001
Posts: 2,516
Likes: 0
From: Lockport NY
Re: Computer lost & found. (nobodyunknown)
I'm not sure, but I think an '84 uses an 870 ECM...
But the ground connections will corrode, get dirty, come loose, etc. over time...
Cleaning them and making sure they get good ground will eliminate a lot of bugaboos...(They also break occasionally)...
The ECM is, uh, "plug & play", like Microsoft can only wish their O/S's were...Just unplug the old one & plug the new one in (with the correct Memory Calibration Pak)...
If your ECM is from a 90 pickup, then someone has done a very complicated conversion, which I am in no way, shape, or form qualified to speak thereof... :crazy:
But the ground connections will corrode, get dirty, come loose, etc. over time...
Cleaning them and making sure they get good ground will eliminate a lot of bugaboos...(They also break occasionally)...
The ECM is, uh, "plug & play", like Microsoft can only wish their O/S's were...Just unplug the old one & plug the new one in (with the correct Memory Calibration Pak)...
If your ECM is from a 90 pickup, then someone has done a very complicated conversion, which I am in no way, shape, or form qualified to speak thereof... :crazy:
