ok, so here's the deal...everything on the harness checks out...

replaced the PTU (power transistor unit), still no spark...

checked the CAS (crank angle sensor) and it's still in very good working condition...but no spark still...

we are scratching our heads guys...and have no idea why it's not sparking...in the mean time we have checked everything else, and everything else seems to be in perfect working order...but obviously we cant check everything until it starts...

please, has anybody else run into electrical spark related problems this annoying? i need help...but most of all, I NEED MY CAR BACK ON THE ROAD!!!

 

Maybe double check all groundz, and try swapping out a known good ecu?

 

scratch that. try swaping a stock good ecu.

 

Is the ecu kicking out any fault codes?

 

check all fuses and relays...make sure that the ignition fuses and relays are working. Ohm out the coil packs, make sure they didnt just a die on you. Are u gettin any power to the coil pack plugs on the harness? You sould read 12V on one wire, 0 v on another (ground) and the last shoud flash really FAST. The last wire is your pulase wire comin from the relay. Check all of those things, is there any other symptoms the car is showin?

 

ok after 2 and a half weeks of playing with wires, checking voltage everywhere, playing with the old NA ptu, the stock TT ptu, and the new one i ordered...tonight we finally got her to startyb switching around some of the splicing we did with the new ptu i ordered...runs real rough though, and we smell a lot of gas, so we know there's at least one cylinder not firing...

tomorrow we compression test and while the plugs are out check which cylinder (s) are not firing...if its just a single cylinder not firing, we can assume it's just a wiring problem with the clip to the plug or something...if it's a pair of cylinders, it may be a small wiring problem with the ptu or the wiring that goes to that spark plug...either way, it's not going to take as long as it took us to get the damn thing to start...

tomorrow: find out which ones are not firing
saturday: fix them...and maybe drive her home!!!

it's nice to make some progress after weeks of trying to figure the same damn thing out...i was starting the lose faith believe it or not...but this definitely made me feel a lot better and gave me a lot of new found faith and motivation...

will keep you all informed as more updated occur...and thanks for all the advice along the way guys...

 

Sounds like timing to me..I'd say get a stock wiring harness, ecu and switch it out. Gurantee to work...quick fix..Solves your wiring problems.

 

21 days and no update........are you ok i hope you got her running!

Good luck maybe one day i ll get to a swap!

 

so got the new harness in this week, worked on it for the few hours we could today, and all i have to say is


F ALL THE HATERS THAT SAY A HARNESS CAN'T BE CHANGED WITHOUT A TRANNY/ENGINE PULL!

but, it was not easy at all...

we stood around for a bit trying to figure out how to do it, couldnt think of a plan, so just made it up as we went, one step at a time....

first, we couldnt find the air saw for the hacksaw blades, so ended up using a pair of pliers and the blade to by hand, while kneeling on the engine, cut through the old harness, just by one of the clips inbetween the engine and the firewall that hold the harness in place, that took a good hour....then ripped out the half of the harness that goes to the engine

next, we couldnt get the rest of the old harness to pull through the firewall, and realized it was because more clips were holding it to the firewall, so i got up there with a kroll bar, and a rubber mallet, lined it up, and hit the harness so that it broke free of the clip, then we were able to, with some effort, rip the remaining half of the old harness through the firewall...

now, we werent sure if we'd be able to feed the new harness through the hole, and didnt want to take the chance of screwing up a $350 part...so we practiced once with the old harness, taking the blue clip that attaches to the ecu, tieing a long spare thin wire to the end of that clip, feeding the wire through the hole, and then pulling the clip in a bit to get it started....i, from the engine bay, angled the clip best i could, then gently tapped it with a screwdriver and that mallet again, and we got it to go through relatively easy....

after one practice run, we decide it's the moment of truth, we do the same thing, only a lot slower and more gentle with the new harness, and it works...smiles all around, we did it without having to do any major work at all...

we then realized that routing the new harness the same as the stock one simply wasnt happening, no way are we gonna be able to route it along the firewall again, so we're just gonna route it along the top of the bay, which is good i guess, less heat exposure being further away from the exhaust...but we do have an extra foot or so of harness just chillin now that we have to fasten and secure away somewhere, that shouldnt be hard at all though after what we just did...


side note: i also recently got that new style PTU to the ignitor chip, which got the car to start (even though only on 3 cylinders...)....but now we realized that the new harness is the same year version as my car, a 1990...so the ptu clip is for the older style ptu, not the newer one that i have to use...so i'm hoping we can splice things around and make it work, but my old harness ptu connector isnt in the best of shape, and i want new...but we have heard there is like a ptu conversion plug thingie, i cant think of the word for it...adapter, thats the word...its an adapter to be able to use a new ptu with an old style harness...if i can i'll just get that, plug it into the new harness where the old style ptu would go, and it has a new style plug on it for the new style ptu...if such an adapter doesnt exist, then we have to do a hack job because i definitely want to use the newer style ptu...they're a lot less likely to just crap out on me than the older style ptu's from all i've read....

 

Please see 2nd quote in signature.......


Lower the cross member far enough so you can run the wires where they were meant to be run. You don't want your engine comartment to look like sh*t; which it will, and don't try to convince yourself that it won't, because you'll be wrong.

 

dont get me wrong, i will most likely do it right soon...but i dont see this being bad at all for the harness any time soon....or any time at all...i dont need the bay to look pretty right away, i've been frustrated and struggling with this car since the beginning of april, i just want to DRIVE IT...probably will enjoy it as is the last few good months of weather we get here in Buffalo, and in mid november when it starts to get sh!tty i'll put it away, and while its away re-route the harness, and have a little more fun making it a better car for the next season...

 

Actually, it could be bad. Once the harness gets really nice and hot, it'll set that way; which will make it extremely difficult to get it run the route that you want it to later.

Just take the extra time, remove the upper plenum and run it the right way. Don't start to half-a$$ it now just because you're anxious to drive it.