JRICHKER I NEED YOUR HELP!

Just finished working on the car another 10 + hours. Good news! Car started. But it fought John and I the whole way.

To make a short story long, we made the correction for the PC ground at the "-" post on the battery. My battery is located in the trunk and the previous owner did some Mickey Mouse electrical work which made a fun few days for us. Like welding the Neg. battery cable to the frame rail so he could keep the stock location of the PC ground wire screwed into the driver's side inner fender well. Plus a lot more BS.

We fixed that, cleaned it up and still would not start. This is where we started throwing small items around my shop and swearing at one another. We straced the 10 g. black and green wire all the way back to the PC and found no breaks.

In the mist of our Pist Offness we had a brain fart. We looked down at the PC and noticed a relay that hides behind the pass. side kick panel with the computer. It's not the fuel pump relay so it must be something like an EEC relay, not sure.

So I had an extra plain ol' relay sitting around and plugged it in. Damn fuel pumps kicked on and started the Notch. WTF! John just about flipped his wig. All this time is was just one very important ground and a stupid relay. There was much rejoice and "oh yeah I'm the man".

I have pictues of all the crap we went through, if you want me to post the pics I will. I even took pics of the relays we swapped out and or replaced. Set the timing, fixed a couple of fuel leaks, set the fuel PSI at 40, bled the brakes, MSD 6 plus wires hooked up, got it to idle on it's own, aligned the front wheels, fixed the electric fan, etc.


What kind of problems are you having? Things I have learned: Make sure you have good grounds, have extra relays handy, learn how to use a mulitmeter, learn to love to check for resistance (ohms), and double check your fuses. Oh yeah, and always have someone with you that knows more about electrical wiring than you do.

John you earned your keep again, Sushi is on me. Yeah you can barrow my slicks.

Today, was a good day. Oops, Bullrun is almost on, gotta go!
 
yo! that is crazy! glad to hear you got it ironed out.

me, ahh just trying to convert a 93 4cyl using 91 engine, engine harness, and pcm...come to kinda find out that due to the years of relocating the fuel pump relays, i got no power to fuel pump and no cranking...hell i dont even have a fuel pump relay.
like you, i am getting very upset. not sure if i should just get a 93 5.0 harness, but then can i use my 91 pcm or do i have to get that too? need that harnes so i can get the pump relay and pretty much be a plug and play deal. dont mind maybe hardwiring in a fuel pump relay, but i fear that i will still be dealing with no cranking when i turn the key. not getting the starter relay to work either...just frustrated and sick of looking at wire diagrams.
so i guess i am in the market for a 93 5.0 engine harness...anybody got one?
i listed my need in the classifieds.

any ideas?
 
Hmmm. Sounds like your project is going to be more involved than mine. I do remember reading many moons ago a guy doing the same thing your trying to do and I think he commited suicide. He had to Frankenstein the harness but others who are smart with electrical wiring like my new Lord and Savior Jrichker might save you a brain hemorrhage.

This is just my 2 pennies cause I hate wiring, I still don't know how electricity gets to my house. Now to me, it would be worth while to have a complete wiring harness to work with. If you don't, and try to mix and match, now your working with two different types of wiring harnesses and that sounds like trouble. I would think you have to have a fuel pump relay. If you ever wanted to add or upgrade the power of the mustang and it involved more wiring, then what. More brain scratching?

I have been told over and over, "do it right the first time." I never listen but it sounds like the right thing to do. As for the PCM, I THINK they are interchangeable from year to year. A lot of guys want the A9L, better tunabilty blah blah blah. I am lucky to have one, my car is an 88, originaly a Speed Density mustang, so a lot has been done to her before I got my fingers on it.

Good luck with your searches. If I hear of a harness I will contact you.
 
Most of the computers are the same just the A9L's are better curves in them and the 93 cobras are better also and are set up to run 24# injecters. I do think the auto trans computers are diffrent,and you caint use a standard trans ECM with an auto.Your no cranking issue could be this little hoodi ki it's the single little wire that goes between the 2 big post wires. I dont know what it's call but if you have a starter relay with 2 of those little posts and you dont put that wire on the correct one it wont respond when you hit the key. Most stock starter relays are a 1 prong hook up so you caint go wrong. The little prong usually have threads on it . Zoom in on this pic to see it better. peace
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john:p
 
thanks for the pic. i checked out mine and its hooked up?
got a 92-93 5.0 engine harness coming this morning, so i cant wait to get it! but then again when it rains, it pours, so i hope nothing else comes up.

i will just be happy to get the right harness and the fuel pump operating properly, then i will focus on the starting problem...with a little luck, i may knock out 2 problems with this harness.
will post update after.
also, not running smog pump or a/c...what do you do with the little vac lines that run through the engine bay in back pass side? plug them up? i hard wired the pump and bypassed the starter relay to see if it WOULD start and it did but then quits right away? can keep it running by feathering throttle, but it wont idle or stay running. any ideas? could it be a combination of everything.
thanks