NAFC

86 non turbo, crashed it with a motor that has only seen 3k miles after a rebuild. worked just fine after the crash too. since the shell was absolutely done, i went ahead and swapped it into an 88 shell with a 6 point cage, 30mm wide body, with the heater n blower units n all that bs removed, including egr removal FAR before the crash ever happened.



things were running great and i even drove the car back from the crash scene without over heating or anything.



the front harness, rear harness, intrument panel harness were all in my new shell from the start. i've swapped my 13B with the emmisions harness, all the relays and coils too.



now i've come to notice i have no power to my fuel pump and no power to my coil igniters. take note, my fuel pump fires right up when i rig it to a battery.



i did a continuity check beginning at the fuel pump where the wire comes from the rear harness. the light LIT UP, indicating there's power going to it.



further on up, the relay under the dash to the side of the steering column also clicks whenever i jump the terminal connecter (the spot that is SUPPOSED to turn on your fuel pump), but it doesn't turn on the fuel pump. i've also open the door on the AFM and it clicks in the same fashion without engaging my fuel pump. i should also mention the top middle part of the connector lights up my continuity tester, verifying there's power comin out of there.



the main relay also clicks with the turn of the key.



i've checked my coil ingiters and they're both within ohm spec.



it seems as though everyone else who's had my problem solved it by changing a fuse or connecting a ground, or even swapping out relay's and crank angle sensors entirely. SADLY, none of this has fixed either of my problem.



its a headache, i dont see any reason for my fuel pump not to operate even when cranking when there's obviously power going to it >.<



perhaps im overlooking something? it's not my first swap or rebuild, i've done stupid things like forgetting to plug in the AFM or the TPS.



some say its the ecu, but that's the one thing i dont know how to check. even that would help :]

NAFC

can i even run an 86 ecu and emmissions harness with the 88's front harness?



i managed to chop up the salvaged harness from my wreck, and i found a wire comin from my main relay that splits up and goes to both coil igniters and the ecu. another set of wires goes to a black 2-prong female connector, and based on the wiring diagram im assuming it's power steering switch (but that doesn't sound right..).



is it a good (electrically safe) idea to just try wiring the one that leads to my coils directly to a power source? sorta the same idea when i checked my fuel pump.

CrimsonPride

If you remove the 2 wire connector going to the leading ignition/coil assy, there is not B+ at the B/Y colored wire with the ignition in the run position, right? If this is the case, I would run down this entire circuit first, checking everything and see what that reveals. It is relatively simple and does not involve the ECU.

CrimsonPride

If there is B+ at the above wire, your ECU probably isn't grounding the other igniter wire to produce spark and isn't grounding the control current to the relay the energizes the fuel pump either. In this case, I would check all of the inputs to the ECU with a voltmeter. You could just have a wiring connector that isn't connected on one of the ECU inputs.

NAFC

i figured it couldn't have been my ecu, its nice to hear hahaha i got really paranoid when i read about that electro-static discharge.



i ended up goin through it and i still think my main relay's at fault. i've swapped two others in and tested them outside the car. if im testing the relays correctly, all of them are bad. sounds to me like im definately doin something bad if theyre ALL failing, especially if one worked just before this swap.



if i stick a wire from my positive terminal into the b/y female connector on the harness, the test light at the coil connector turns on. when i remove the wire and plug the relay back in, it clicks, but doesn't power the coils.



if i wire the relay to the battery and test for current in any of the male prongs, i get nothing. but all 3 click. the light doesn't turn on and an ohmeter reads nothing.



since i got three of em anyway, i took apart one and read up on how relays work. from what i figure, it's nothing more than an electromagnetic switch. i took that same light to see what prongs are gettin power and the only ones that light up are the b/y ones. i can include photos :/

CrimsonPride

When testing relay out of the car are you wiring battery+ to one of the control terminals and battery- to the other, and checking for continuity (ohms) on pairs of the other relay terminals that the relay is supposed to connect together. When the control terminals are energized, it just shorts other pairs of terminals together. You won't get current out of any of the other termials unless you put current into the other member of the pair. Also, the pairs of terminals that are connected together are not always across from each other. They could be side by side, diagonal, etc.

NAFC

well, that helps a lot. if that's the case, then all my relays are good. im going crazy so i continued tracing wires. i found that a blue wire from the circuit opening relay powers the pump. if i wire it from the plug between the front and rear harness, it turns on. i can also wire my coils in the same way.



now another problem arose, now i can't start my car using the key, the only way it cranks is if i power it directly from the circuit opening connector. odd?



anyway, despite the fact that my coils are getting power now, they dont fire. i hooked up a timing light and even disconnected a wire to see if it arcs. nada.



guess imonna go back to the office (garage)

NAFC

CAS checks out, coils check out, all my grounds and connections are good as far as i know, any suggestions as to why im still not getting spark?

CrimsonPride

In some of the foregoing I believe I understood that: you had removed the main relay and jumped in B+ to the wire that goes to the igniter and that you got B+ to the leading igniter that way. Correct? But with the relay in and everything connected you don't. If so, check here again at this connector with the relay removed. There should be 2 wires here that have B+ all the time. It comes straight from the battery, through the main fuse box near the battery to this relay. When the relay engages it should connect one of these wires to the one going to the leading igniter. If not check connections to and from this fuse box.



If you don't have a full wiring diagram, you can get one here:



Index of /main/factory_service_manual/1986_1988