MUCH help needed, many different problems inside.

[raven2345]

So back in December I swapped from auto to 5spd. Well I got a little anxious and left a clamp loose on the coupler holding my MAF. MAF fell out of the coupler, through the clutch fan and belts, pulled my wiring harness a good 8 inches or so down, sheared a few different wires and shorted out the ignition circuit on my ECU.

Fast forward now to having a new ECU and soldered the sheared wires back together. My tach doesn't work, and the car responds horribly to applied throttle when in neutral. When under load, the throttle basically does nothing for me. The car doesn't accelerate for anything. I have an Apex'i SAFC Neo wired up, and the tach on that also reads 0rpm, always. With the MAF unplugged however, the car will run fairly decent up to the 2500 limit, with an intermittent misfire. The throttle action is also kind of weird - sometimes, it's like the car accelerates when I let off the pedal. Anyways, I've come to the conclusion that something along the CAS circuit is screwed up, which is why the car runs better without the MAF (limp mode, ignoring most sensors, like CAS that I assume has a horrible signal or none at all, or another burnt out ECU).

Replaced parts:
TPS -new
Dizzy -used
ECU -used

I'm sure I'm missing some more information here, so please ask away.

Any help or ideas are welcome.


Power transistor and coil wiring


MAF wires soldered back together


General harness picture


Idle air stuff and plug cut, all wires are 100% blocked off with liquid electrical tape

[LoserCard]

Well first things first:

1. Check the continuity of all wires involved.
2. It sounds like your MAF is damaged so test it or get a new one.
3. It may be possible that some wires are ripped/crossed in the harness and may be shorting out your ECU, so before doing anything check the harness for damage.

P.S. I have that same vacuum T in the third picture, lol!

[alms24sebring]

wow thats a hell of an issue. I would say that ^ is mostly right. You may have likely shorted a wire so check all fuses first then check coninuity, followed by any check engine codes. Those should give you hints as to whats going on. Ive run across the 'unplugged MAF sensor running better' before but dont remember what happens in that case.. sorry

[raven2345]

Well first things first:

1. Check the continuity of all wires involved.
2. It sounds like your MAF is damaged so test it or get a new one.
3. It may be possible that some wires are ripped/crossed in the harness and may be shorting out your ECU, so before doing anything check the harness for damage.

P.S. I have that same vacuum T in the third picture, lol!

I guess continuity I should check.. Hahah, it honestly never really popped into my head since I just work with the ones that were visible by eye. I have put my MAF on another 240 that DOES run well, and it made no difference to it. I guess replacing my harness is the next easiest, surefire way to make sure it's not a harness issue...

Are you by chance, running that tee to a boost gauge, even though you're N/A? Lol, I used it to check for vacuum leaks, and haven't disconnected it yet.

wow thats a hell of an issue. I would say that ^ is mostly right. You may have likely shorted a wire so check all fuses first then check coninuity, followed by any check engine codes. Those should give you hints as to whats going on. Ive run across the 'unplugged MAF sensor running better' before but dont remember what happens in that case.. sorry

'Tis, a hell of an issue. I know my fuses are good, and I amazingly have no engine codes, except for the MAF, when it's unplugged.

Thanks for the help guys.

[raven2345]

Joy.

Turns out the ECU I bought and have been driving with for the last few months, is apparently out of an 89 SOHC. I have a 91 DOHC. Does a single cam ECU, seriously, fit the dual harness? And run, at that? Now, to find the correct ECU, and probably redo my timing, I'd imagine.

[LoserCard]

Hahaha! I find it funny that your car can somewhat run with the sohc ecu.

[raven2345]

^^^I found it funny how when I pressed "View your posts," the first thing I see was the 'loser' in you're username. I definitely never considered the possibility of an SOHC ECU even plugging into the dual harness, but I'll never forget about it. Anyways, now I have to redo my cam timing to "set" it right with the correct ECU.

[LoserCard]

^^^Not sure if that was a joke or insult, but anyways... Yeah, last time I had a weird problem I couldn't diagnose, my ECU was the last thing on my list. It sucks that I changed everything else before testing it. Good luck with your car!

[raven2345]

^The loser being me. Lol i think how I ran it so long on the wrong ECU, might have burnt a few things up in the motor because my cam and ignition timing are set right, and it backfires through the intake. Should be fun..