livinnstix

Hey guys,

Have the car listed in the title. chasing a fueling issue, I found the relay under the seat and the inertia switch in the trunk. I tracked down a wiring diagram and this is what Ive come up with at the relay under the seat. (used a multimeter and these are the readings)

Red/Black - 12V - turns relay on and off

Tan/Light Green - 12V - should ground relay? (attempted to force a ground and made the dash go crazy)

Yellow - 12V - power wire

Pink/Black - dead - fuel pump
(fuse has power in and out)

If someone can tell me which wire is supposed to be the ground.

I jumped the yellow wire to the pink/black wire and makes the fuel pump turn on but still no fuel to the injectors (throttle body injection).

First post and Ive tried doing searches and can't find what I need so I was hoping someone could help me out and point me in the right direction. The wiring diagram I have doesn't show much just components and there wires but doesn't show where the power comes and goes.

Today I chased my fueling issue to the injectors at the CFI. I rented a noid test set and no lights at all. Broke out the multimeter and I have 12V to all 4 wires at the injectors (white/orange, Red, Red, White/Green). I disconnected the injectors and checked them with positive and negative test leads and they clicked. I took the distributor module off and had that checked and it was good. At this point Im looking really hard at the ECC.

I can get the car to run on starter fluid/gas in a cup but the injectors are not firing.

Issue: Injectors not firing, fuel pump not kicking on without jumper wire.

Any help would be greatly appreciated. Thanks in advance.

mjr46

there is a fuel pressure test port on the TB , YOU SHOULD HOOK A GAUGE TO IT. ecm supplies ground to the relay, it should supply ground to relay when key is pulsed on and in the crank mode, if it doesn't see car cranking after 2 sec then ground to relay is removed, the ecm uses PIP to determine if car is cranking, PIP is generated by the stator in the dizzy and cleaned up by the tfi module, so if a prob exists with tfi the ecm may not know car is cranking therfore not supply ground to relay, use a test light and hook the clamp to B+ AND back probe the ground at the relay, it should light then go off when key is switched on, if it does all is well there then trace back to relay or pump, just because you can manually turn pump on, does not mean it has the ability to generate volume, if the pump rotors/vanes are damaged, this is why I use a FP gauge.

mjr46

when ign switched on 12v should exixt on r/bk wire = if it does = eec relay good
T/LG should briefly supply ground for 2 sec to relay and in crank use a test light as I stated hooked to b+ AS i STATED , if it lights and goes out or stays lite while cranking = ecm side good, yellow wire is power supply to pump before relay contact, should have 12v and once car ign is switched on and or in crank mode if all other wires check out above then relay should close contacts and B+ is bridged over the contacts from the yellow to pk/bk, if a click is heard and power does not flow across contact = bad relay, run said tests and report back, and don't force the ground on the ecm by supplying a ground wire shoved in the connector, you'd have to cut the wire to remove ecm safely from the loop

http://www.google.com/imgres?imgurl=...QEwAA&dur=4873

mattdel

no injector pulse combined with no FP power would lead me immediately to a PCM failure... With that said, PCMs rarely ever fail, so a thorough testing will be required. Listen to the man above me, he is wise.

livinnstix

Thanks for the reply, Ive been pulling my hair out all weekend. Im gonna look into what you've said this evening after work and go from there. I never did get a chance to check fuel pressure.

Ill post my results.

livinnstix

Can I check the PIP or TFI?
"use a test light and hook the clamp to B+ AND back probe the ground at the relay" Which relay are you referring to?

I can't check fuel pressure until I figure out the ground issue you because the pump doesn't turn on unless I put in a jumper wire.
Where is the EEC relay? I took the computer out but don't see it. Do I need to take the dash out?

When I unplugged the computer one of the pins came out in the plug. See attached photos.

<a href="http://s830.photobucket.com/albums/zz229/livinnstix/?action=view&amp;current=EEClabel-1.jpg" target="_blank"><img src="http://i830.photobucket.com/albums/zz229/livinnstix/EEClabel-1.jpg" border="0" alt="Photobucket"></a>

<a href="http://s830.photobucket.com/albums/zz229/livinnstix/?action=view&amp;current=burntcomputer-1.jpg" target="_blank"><img src="http://i830.photobucket.com/albums/zz229/livinnstix/burntcomputer-1.jpg" border="0" alt="Photobucket"></a>

<a href="http://s830.photobucket.com/albums/zz229/livinnstix/?action=view&amp;current=brokenpin.jpg" target="_blank"><img src="http://i830.photobucket.com/albums/zz229/livinnstix/brokenpin.jpg" border="0" alt="Photobucket"></a>

livinnstix

mattdel

Hey good find. Looks like that board got wet. I just happen to have a computer out of an 86 laying around. Its in the garage right now, and its pouring rain, so I'll check the numbers on it tomorrow. Probably not the same though, EFI VS TBI

livinnstix

Wonder what the differences would be? Id be intrested in buyen it from you if it would work for me. Where would I get a new EEC? I assume just run to local auto parts store? Unless anyone knows of a better alternative.

mjr46

86 and up ecms will not work!! inj are fired in sequence = 8, you have 2 only