Heres the extra pcm, yes it came withthe car when i bought it with some other extra parts. Yeah ive installed it once before and the car didnt even like to start with it plugged it. It only worked with it unplugged.
will only start using starting fluid but will die shortly after
- Thread starter jtw357
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Heres the extra pcm, yes it came withthe car when i bought it with some other extra parts. Yeah ive installed it once before and the car didnt even like to start with it plugged it. It only worked with it unplugged.
luigisho
SHO Member
I haven't seen a ribbon style one in a long time. I would not bother with it at all. If you have an aftermarket MAF I would run a good stock one and a regular unchipped pcm. Even with an aftermarket MAF and no chip it should start and run. Maybe with air:fuel ratio off but still should run. You have wiring issues before this?
Well orginally 14’ it was wired for the battery to be in the back. Sometimes itwould start sometimes no power/nothing. No wiring changes until 17’ after it had already bogged down to a crank no start (may have been after i installed another fuel pump again) before that in 16’ it would start but run really bad/undriveable until crank no start that i previously mentioned. Now i have power all the time, it doesnt look the prettiest but i was getting power all the time now instead of sometimes. Symptoms before it gave in 15’ were backfiring, would cut off after downshifting, intermitttent cutting off in the middle of driving. So two weeks ago 17’ installed a crankshaft sensor and now ive gone from crank no start to start with starting fluid. I saw something unplugged the other day underneath the throttle body, it was a little ways down... i could be nothing but maybe it goes to somethin
luigisho
SHO Member
Yeah something is off. There's too much wiring stuff going on. Hopefully it's a faulty part but if it's wiring that's a nightmare.
Usually, if there is a chip installed in these pcms, they will not report codes properly. In that case, I would remove the chip to test. In fact, there are very few chips that actually help these cars, so it might be best to just remove the chip and leave it off anyway.
luigisho
SHO Member
Hopefully pcm will remedy this but if you get too deep in man hours-- now sometimes say dump it after too much work vs value but it's a nice looking car so I would save this one--
You can consider, if you get to the point of throwing your hands up that a replacement harness and power cables might be daunting but a more certain remedy. Just food for thought if it gets too funky. That check engine light should blink something. Something is shorted out somewhere-at the pcm or wiring or something.
You can consider, if you get to the point of throwing your hands up that a replacement harness and power cables might be daunting but a more certain remedy. Just food for thought if it gets too funky. That check engine light should blink something. Something is shorted out somewhere-at the pcm or wiring or something.
Thx for all the help. Im going to do two things to rule out some suspicion i have. One is the fuel pump, i used to hear it make a whining sound when engaged and the other day i went by the fuel tank to see if i heard it, and all i heard was a “ click”sound. In the past you could hear it whine while still sitting in the car. So im going to rent a tool from autozone and test the fuel pressure while cranking and then move to my other suspect the “injectors”.
I was getting a foul smell in the car while it was still running but performing poorly. Idk these could be the original injectors... i just hope i dont have to take too much off the intake to get down to them to test injection pulse.
Seems like the car wants to go, i hope i can figure this one out.
To respond to what you said, the original computer which is in there now, would report codes with key on engine on without a problem, besides returning a code # i dont remember saying rpms too low too test, when it was running poorly, besides another code which was egr related. Not sure why key off doesnt want to work idk...
Its raining today, tomm im back at it
Exactly i was trying to get it back going, this was in good condition when ingot it besides the dumb wiring the battery to the back, but im getting power... im hoping the harness is the last thing for real, in my other reply im going to rent a fuel pressure tester from autozone. I just dont hear the fuel pump prime like it used to and my next suspect test for pulse at the injectors... im just dreading pulling the fuel pump out again lol, but the gas is also bad in there by now anyway. It smelt like varnish the other day when we pulled a plug.
I was getting a foul smell towards the end of driveability, bad hesitation, backfiring, cutting off
Its raining today so im going to start again tomm.
I am seriously considering selling it even after revive it. I do really love sho their awesome. Thinking about rwd 8 cylinders but... i would still try to get it to the best shape i possibly can within reason budget wise.... poor sho i feel bad for it. This one has some goodies, coilover kit (lowered), magnaflow headers and exhaust, not just the mufflers. Polished alminum heads, interior in pretty good shape considering age, and the sunroof still works.
So hopefully i figure it out...
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luigisho
SHO Member
Ah, save it for the kid. They grow up fast. Sounds like you have multiple issues. You'll be chasing your butt on this one.
pjtoledo
'ol man in the SHO
have you pulled the connector off the CCRM/IRCM and performed a continuity test on pin 5 in the harness? its a pink with black stripe wire, and is the power line to the fuel pump. that wire goes to a splice S152, one leg goes to the PCM on pin 8 for a 3.2, pin 19 for a 3.0 for "fuel pump monitor" , the other leg to connectors C122, C100, C214 then the inertia switch, then to C309, then splice S427 the fuel pump then splice S319, then ground.
you should see the resistance of all the wiring and the pump in that circuit. not sure of the exact reading, I would check a known good motor and add 4-5 ohms. maybe 20 ohms total???
you can also jumper power to that pin 5 to force the pump to run, be sure to include a fuse in the jumper wire.
disclaimer: I'm using a 92 EVTM book, the fuel pump circuit for a 1991 may be a bit different because of the dropping resistor. I'll see if I can find my 1991 book.
I seem to vaguely recall that as the PCM monitors power to the pump if it detects an issue it will signal the CCRM to stop power to the pump. in that scenario you will not see power on pin 5 even if the key is on. its been a few years, so "buyer beware" on that.
you should see the resistance of all the wiring and the pump in that circuit. not sure of the exact reading, I would check a known good motor and add 4-5 ohms. maybe 20 ohms total???
you can also jumper power to that pin 5 to force the pump to run, be sure to include a fuse in the jumper wire.
disclaimer: I'm using a 92 EVTM book, the fuel pump circuit for a 1991 may be a bit different because of the dropping resistor. I'll see if I can find my 1991 book.
I seem to vaguely recall that as the PCM monitors power to the pump if it detects an issue it will signal the CCRM to stop power to the pump. in that scenario you will not see power on pin 5 even if the key is on. its been a few years, so "buyer beware" on that.
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Can i use the schrader valve to test fuel pressure or do i need to use a line from the fuel pressure regulator... just making sure.
luigisho
SHO Member
That's what the schrader valve is there for
Okay so im back, funds kept me from being able to do anything.... question... if i decided just replace the wiring harness? Would a harness from a 92’ work? I have a 1991 mtx.... or do u think its a better move to get a power probe and try to chase the problem down?? Thanks
sperold
Last to Know
Get an EVTM (Electrical and Vaccuum Troubleshooting Manual) for a 91 Taurus from E-bay, usually less than $20.00, and follow it to find any wiring issues.
Keep your original harness as there are always changes between the years.
Once you know the wiring and connector colours and locations, troubleshooting gets a lot easier.
Keep your original harness as there are always changes between the years.
Once you know the wiring and connector colours and locations, troubleshooting gets a lot easier.
Advice taken, i just ordered one off ebay should be here 2/9–2/16. Greatly appreciate the advice, thanks
ok have the book on hand.... do by any chance do you know what the voltage is supposed to be for the blk/pnk wire for the fuel pump.. is it 12v engage or should always be hot.... just wandering if you knew off hand...
FRDSHOGRL93X3
SHO Member
You ever figure this out?
GT94SHO
Member
I had a similar problem with my Gen II and found the answer on this forum. The low coolant level sensor in the coolant bottle was bad and it blew a fuse which also kills power for fuel pump.
Unplugged faulty low level sensor, replaced small 10A fuse, been running fine for years.
Could you have a similar problem? Go through every fuse in the fuse panel(s) look closely for one blown, that's a starting point.
Unplugged faulty low level sensor, replaced small 10A fuse, been running fine for years.
Could you have a similar problem? Go through every fuse in the fuse panel(s) look closely for one blown, that's a starting point.
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