North American Turbocoupe Organization



car is a PITA.. 87 tc
turbo_crazy Offline
Senior Member
#1
ok, so.. i decided since i'm not going anywhere until at least next week with the car, i'd clean up under the hood and throughout the rest of the car, as well as get a jump start on some of the things i have planned for the car.. so i decided to finally get rid of my A/C and factory fan wiring.. i decided to just pull them straight from the connector at the relay box, pulling the pins out with them.. no other wires were cut, pulled on, etc..

now, the issue (yes, i need a tissue).. when i turn the key on, the relay box starts humming loudly and my fuel pump runs continuously.. the car won't start without putting the pedal to the floor, hardly starts and stalls if you let the rpm's drop below 1500.. and all the while, the tach acts really strangely, randomly pulsation up and down almost 500rpm's, while you can hear the motor running steady at the same rpm, zero fluxuation

any clues? i'm getting ready to check out some wiring diagrams to find and check the ground(s) for the box itself
87 TC: 5spd, started B234F head swap (overall setup changing), Quarterhorse, T3/T4 63 a/r, 3" exhaust, walbro 255, tubular front clip, 5 lug swap, 17x8 front/17x9 rear cobra r's, wilwood 4 piston calipers (rear only, for now), lightened 471lbs so far
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turbo_crazy Offline
Senior Member
#2
If any circuit is less than 5 ohms, there is a short to ground and that needs to be repaired. If all circuits read over 5 ohms, then it is possible your EEC is faulty. EEC failures are rare, but can happen due to electrical spikes that result from improper jump starting or unhooking the battery while the engine is running.

..uh oh..
87 TC: 5spd, started B234F head swap (overall setup changing), Quarterhorse, T3/T4 63 a/r, 3" exhaust, walbro 255, tubular front clip, 5 lug swap, 17x8 front/17x9 rear cobra r's, wilwood 4 piston calipers (rear only, for now), lightened 471lbs so far
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turbo_crazy Offline
Senior Member
#3
well.. did the tps connector ohm test with the vam and bps unplugged.. bps plugged in is around 6.3ohms.. vam plugged in.. .89ohms.. got the car to idle by turning the idle screw in (idling around 1200rpms). kind of choppy, but still revs right up like it's supposed to and sounds like it's supposed to.. plug the vam in and it dies as soon as i hit the TB linkage, to bring the rpm's up.. still doesn't explain why my relay box is humming, but my fuel pump is no longer running continuously, so i assume i'm on the right path.. i hope..
87 TC: 5spd, started B234F head swap (overall setup changing), Quarterhorse, T3/T4 63 a/r, 3" exhaust, walbro 255, tubular front clip, 5 lug swap, 17x8 front/17x9 rear cobra r's, wilwood 4 piston calipers (rear only, for now), lightened 471lbs so far
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Jeff K Offline
Administrator
#4
Did you carefully study the circuit diagrams for the systems you removed before altering the electrical system? Many electrical subsystems interact with one another, and altering one subsystem will impact others. I say put it all back like it was and see if in now runs OK.

How familiar are you with reading circuit diagrams, and electrical troubleshooting with a test light and DMM?
Jeff Korn

88 Turbo Coupe: Intake and exhaust mods, T3 turbo at 24 psi, forced air IC, water injection, BPV, Ranger cam, subframes, etc., etc.
86 Tbird 5.0 (original owner): intake, exhaust, valvetrain mods, 100 HP N2O, ignition, gears, suspension, etc., etc.
05 Taurus SEL Duratec daily driver
04 Taurus Duratec (wifes car)
02 Pontiac Grand Prix GT
95 Taurus GL Vulcan winter beater
67 Honda 450 Super Sport - completely customized
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turbo_crazy Offline
Senior Member
#5
i get pissy with diagrams, but i can read and understand them.. What makes no sense is the fact that the wires i pulled haven't been connected to anything for 2 years and nothing was cut when removing the wires/pins.. Only thing i cut was a ground wire that went from 1 of my fan plugs, that was grounded to the apron, which wasn't a factory ground and was deemed useless.. It just ran straight to the driver side fan plug and that was it
87 TC: 5spd, started B234F head swap (overall setup changing), Quarterhorse, T3/T4 63 a/r, 3" exhaust, walbro 255, tubular front clip, 5 lug swap, 17x8 front/17x9 rear cobra r's, wilwood 4 piston calipers (rear only, for now), lightened 471lbs so far
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turbo_crazy Offline
Senior Member
#6
and i couldn't find any pin-specific diagrams, so i only touched wires that went directly to dead-end plugs
87 TC: 5spd, started B234F head swap (overall setup changing), Quarterhorse, T3/T4 63 a/r, 3" exhaust, walbro 255, tubular front clip, 5 lug swap, 17x8 front/17x9 rear cobra r's, wilwood 4 piston calipers (rear only, for now), lightened 471lbs so far
Reply

turbo_crazy Offline
Senior Member
#7
does anyone have a relay control module pin diagram? thinking maybe i may have pulled something by accident and didn't realize it.. pump is running constant again
87 TC: 5spd, started B234F head swap (overall setup changing), Quarterhorse, T3/T4 63 a/r, 3" exhaust, walbro 255, tubular front clip, 5 lug swap, 17x8 front/17x9 rear cobra r's, wilwood 4 piston calipers (rear only, for now), lightened 471lbs so far
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Jeff K Offline
Administrator
#8
I don't have a IRCM diagram in electronic form, but pump running all the time with key on is often a sign of a fried PCM, or the pump control circuit from the PCM to the IRCM is shorted to ground. PCM grounds this circuit to run the pump. Will the PCM output codes? If it won't output codes, this is another sign of a fried PCM.
Jeff Korn

88 Turbo Coupe: Intake and exhaust mods, T3 turbo at 24 psi, forced air IC, water injection, BPV, Ranger cam, subframes, etc., etc.
86 Tbird 5.0 (original owner): intake, exhaust, valvetrain mods, 100 HP N2O, ignition, gears, suspension, etc., etc.
05 Taurus SEL Duratec daily driver
04 Taurus Duratec (wifes car)
02 Pontiac Grand Prix GT
95 Taurus GL Vulcan winter beater
67 Honda 450 Super Sport - completely customized
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turbo_crazy Offline
Senior Member
#9
negative on pulling codes.. so it's likely my ecu is fried? cute.. even more of a reason to go standalone..
87 TC: 5spd, started B234F head swap (overall setup changing), Quarterhorse, T3/T4 63 a/r, 3" exhaust, walbro 255, tubular front clip, 5 lug swap, 17x8 front/17x9 rear cobra r's, wilwood 4 piston calipers (rear only, for now), lightened 471lbs so far
Reply

Jeff K Offline
Administrator
#10
It is possible the PCM is fried. Another sign of fried PCM is cooling fans always running.

Is the orange O2 ground wire grounded at the turbo inlet? If that ground is not connected, PCM won't output codes.
Jeff Korn

88 Turbo Coupe: Intake and exhaust mods, T3 turbo at 24 psi, forced air IC, water injection, BPV, Ranger cam, subframes, etc., etc.
86 Tbird 5.0 (original owner): intake, exhaust, valvetrain mods, 100 HP N2O, ignition, gears, suspension, etc., etc.
05 Taurus SEL Duratec daily driver
04 Taurus Duratec (wifes car)
02 Pontiac Grand Prix GT
95 Taurus GL Vulcan winter beater
67 Honda 450 Super Sport - completely customized
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