FoxGT

If your eec relay isn't clicking on when the key is turned to the on position then the problem is definitely not the computer, if the relay isn't coming on then the computer won't have power. That does make the problem easy to figure out though, now you know that the problem is either that the relay doesn't have power going to it or has a bad ground. Follow the ground & power wire for the relay itself. Either it's not grounded or the 12v key on power source isn't connected. Follow the wires on the relay & you'll find out what's wrong.

If you're swapping to a v8 dash harness, make SURE you get the same year harness & make sure the plugs are the same. Also you're going to have to rewire the body harness unless you get that too.

I personally would never attempt the full v8 wiring harness swap ever again unless I had a single donor car to get all the wires from.

It doesn't matter if the 4 cylinder & v8 harness are the same year, they're still pinned different (at least all of them have been that i've swapped on)

Whether or not you choose to go carb or not is your decision, but I can honestly tell you that the reason it's not working is going to be no more than 4 wires. And I can 100% guarantee they're going to be at the plugs. It could even be as little as one wire keeping it from going.

You figure it out in 3 stages.
1st get the eec relay to turn on (which means following the wires coming out of it)

2nd getting the fuel pump relay to kick on (following wires from it) (the fuel pump relay won't come on unless the eec relay comes on. The eec controls fuel pump relay ground (tan/light green wire))

3rd getting the car to crank.

sushi214

yes, I tried doing what you did with only replaceing the engine harness and that was no good. You had a lot more luck then I though, nothing on mine was working lights horn heater etc. Tried switching pins and tracing wires for weeks and like I said finally just bought all new harness out of a junk car, engine harness, dash harness and even tail light harness. put those in and that did it. still trying to tweak the tuning aspects of it and have a few minor wiring issues like hazards for some reason and the heater blower but other then that it's good. I had a 93 4 cyl and an 89 v8 bought all 91 wiring. I strongly recommend buying a whole wire set from one car if possible then you know they all go together. I found mine pretty cheap through the internet at some junkyard and had them ship it to me. The little extra money and time to install the harnesses especiallythe dash harness is nothing compared to the hours spent tracing wires and not getting anywhere.

GaryBisiniere

thanks for all the help guys im going to trace those wires for the relay tonight or tommrow sounds like all i should have to do is trace the power and ground wire and im pretty sure that there just not ligning up at the plugs

sushi214

Good luck, hope you get it. I know the frustration you are going through. I even payed some "wiring expert" 2G and it still wasn't right. Thats when I ripped them all out and put new ones in.

GaryBisiniere

figured out one of the wires came out of the eec relay. now all the eec clicks, fuel pump relay, and sensors in engine bay sound like they are turning on. but the orange/blue wire that goes into relay isnt getting power so the fuel pump dosent turn on.

GaryBisiniere

by the way i have a summit efi pump with a relay that is run off the fuel pump ignition power wire...

GaryBisiniere

ok so the red/black wire on the fuel pump relay does not have power but all the other wires do, so i need a new relay, but for now i jumped the wires. my new question is my fuel pump isnt turning on but i have power at it... i took it off and connected it to the batter and it worked fine. suggestions?

FoxGT

No good
I do most of the wiring on peoples cars just for the $ it cost for supplies & gas $. I do it mostly for the experience though. So I don't mind wiring people's cars for free.
There are four wires on your fuel pump relay. There should be two thick ones & two thin ones. One of the thick wires has a constant 12v to it (even with the key out). The other thick wire goes to the inertia switch (makes the fuel pump shutoff if you're in a wreck), then from the inertia switch to the fuel pump....
The two thin wires are what triggers the relay to close the circuit between the two thick wires (causing the fuel pump to turn on). One thin wire should have 12v (with key in on position). The other goes to the eec where it controls the fuel pump relay ground (so the pump doesn't stay on constantly when key is in the on position, it makes it shut off when the car isn't running). I made a picture that might be able to help you out.



You can diagnose the problem here. Check the constant 12v wire, make sure it has power. If not then it could be due to it being pinned wrong on a plug. If that's good...

Check the small power wire (12v key on wire) with the key in the on position. If it doesn't have power, trace the wire, if it's bad it'll more than likey be due to being pinned wrong on a plug. If it's good....

Check the relay ground. You can do this just by using a small gauge wire, touching one end to a bolt on the body (preferably one that doesn't have paint on it) then pushing the other end into the back side of the relay (this is called back probing). If the relay clicks then more than likely the eec isn't grounding it. This is more than likely going to be the problem.

After those if still nothing, check the thick wire going to the fuel pump to see if it has power (with key in on position). If it does, but the fuel pump isnt coming on, check to see if it still has power after the inertia switch (small black box in the hatch by the trunk release, but a little to the left (drivers side). If that doesn't have power then the relay either needs reset or replaced (or you could just jump it). If it still has power then the fuel pump connector is bad or the fuel pump - wire has a bad ground.


Let us know the results of this...

GaryBisiniere

update! got it to work. ended up being a loose terminal on the positive side of the pump.... prob be the last time i ever buy anything made by summit to save a buck haha
but i would really like to thank everyone who followed the thread and gave as much help as they could
thank you

FoxGT

Good to hear. Let us know if you have any more problems