jordadms07

Okay so let me start this thread off with I do not like working with electronics at all. They seem to be the death of me. So the problem/story goes a little like this:

The car is a 95 SC300 auto to 5 speed swap, na 2j, running on 95 GS300 ecu. When I first got the car I noticed it was kind of sluggish(even more so than an NA 2J already is) and it seemed to sound a little odd at idle. So first things first see if its missing. Well sure enough first injector clip I pull for cylinder 1 the prongs in the injector are bent over and it is not plugged up(jackpot right?) just straighten them out and plug it in. So I try that and no difference really in running and it starts to white smoke a little so then of course I think the injector is stuck open so I cut the car off and i still hear fuel flowing. Go out and unplug that injector and it stops. So then the idea of maybe it's an ecu issue pops up. Pull the ecu swap it for a core on another ecu identical to it that was just professionally rebuilt. Drove 3 hours each way to do that. Get back put it in plug the injector back up and guess what still filling with fuel after I cut it off. Back to the drawing board took it to a friend that is good at wiring and is a Toyota Master Tech he check continuity etc, etc, on the no.1 wire find that I have 12v on both the ignition wire and the ground pulse wire. So then the idea that the wire has a broken spot in it so for test purposes he pinned in a jumper wire at the ecu and unpinned the yellow wire that runs to injector 1 and then ran it to a jumper harness that we made. Plug all of that up check for power and all seems well no more 12v on both sides. Great we should be in business plug it back up and still sound like it is down on 1 cylinder but no more constant fuel or running insanely rich. Well I decided then to tear into it check the plugs and the injector on that cylinder. Pull the spark plug and it wasn't brand new but not bad at all test it for spark and there was good solid spark. Pull the fuel rail and injectors and here I thought I had surely found the last piece of the puzzle it had california emissions injectors all but cylinder 1 had a rough looking federal emissions one. Ordered all brand new injectors. Last night I installed all 6 new injectors, 6 new NGK double platinum plugs gapped at .44, checked compression on no.1 while it wasn't the best given the gauge wasn't the highest quality either it showed about 150psi, not the best but should still fire fine. Put it all back together and fire it up just waiting to finally meet my cylinder 1 buddy I've been missing for a while and nope still the same old thing from last time. Not dumping fuel but no fire out of cylinder 1. I literally can't think of anymore pieces to the puzzle I'm ready to light this car on fire and let it burn. If anybody has an idea I am fully open to hear it because I'm fresh out of them.

t2d2

iTrader: (8)

I'd love to read along, but that paragraph is overwhelming.

ems

iTrader: (1)

I think the solution is to always drive the car at wot so it can properly use all that fuel that is dumping into the cylinder!!!!

Yeah.. that's the ticket!

Hopefully your toy tech can sort it out, good luck.

estomax

iTrader: (2)

the injectors here are 'sinking' type, that means there is always 12v (from the batttery) going to the injector, and then the ECU grounds it to turn it on. If the injector is always on it sounds like somehow it is getting grounded (shorted wire or ECU output) and the injector is on.

your wall of text is confusing, is the problem that the injector is always on still? that is what it sounds like.

Marko

jordadms07

Sorry for the long paragraph. Originally the problem was that the ground wire was hitting a 12v positive and I was getting 12v on both wires to injector 1. I replaced that wire and fixed that issue. Then realized that it still didnt run right so I put all new injectors in it. Fire it up and that cylinder is still not right. So my question is what is left to replace? ECU is rebuilt, injectors are new, plugs and wires are new, and the ground pulse wire is new. So there is nothing left untouched that I can think of.

LoveSCs

iTrader: (2)

Is there any way that you could have fried both of those ECU's before fixing the shorting wire issue?

grumpi300

iTrader: (1)

i took the time to read. ok so if all the spark plugs are firing, and it has good compression, < doesn't mean valves can be adjusted right also, good time to check, and you have new injectors all across, then maybe, just maybe that number 1 injector or spark plug is bad. swap them over to another cylinder and switch that cylinder to number 1. i'd go furthest from firing order so you know its not just carrying over to the next cylinder to be fired. < idk if this makes sense to you or not. just switch to number 6 cylinder since firing order is 1-5-3-6-2-4.
if that still doesn't fix the problem, another suggestion would be to re-time the distributor. maybe just maybe its not timed or installed right? need a timing light and jumper wire to do it correctly.
if that still doesn't work, double, triple quadruple check that you have the right pin on the ecu for the ground on that injector. also make sure its on the proper side of the injector.
lastly, I cant see this being a possibility but I've seen/heard of this happening on bent fuel rails.
since fuel enters the back of the rail and moves its way forward, maybe the outlet on number 1 injector could be clogged. since its a straight rail, I don't see this happening but doesn't hurt to check. just take off the rail and put brake cleaner/ fuel through it and make sure its coming out of all cylinder outlets.
sorry for the book but i'm really trying to help here.
also make sure that the o ring for the injectors aren't plugging up the fuel flow into the engine.

estomax

iTrader: (2)

is the ground now floating on injector 1 when you unplug the connector and ohm the wire to ground? if it is grounded still then it is still turning on the injector at all times because the other wire has 12v and that completes the circuit.

jordadms07

thanks for the replies, I put a noid light on number 1 and am getting no ground pulse wire appears fine and is for sure in the correct pin on the ecu no question. Second is it possible that when that wire was shorted and getting 12v when it is supposed to be a ground could it have fried that ground pulse in the ecu. Because this ecu though new when i first had it in the car it was getting 12v sent to that ground for some time. Thats about the only thing i have left. I even checked from the wire itself not the connector straight to a 12v off the battery and the noid light gave me no signal of a ground pulse. And the fuel flow to that injector is fine and it sprays fine if hooked up to a direct power source. So no injector problem. Has to be ecu I guess. I'll send it back to have it repaired.

estomax

iTrader: (2)

the noid light appears to work correctly on the other injectors though right? just as a sanity check..

it is a good chance you could have fried the ECU with a shorted 12v connection, because the injector coil adds some load which limits current flow. as far as whether it is repairable i couldn't tell you. make sure you tell whoever you are sending it to that you suspect that to be the problem.

jordadms07

Yep noid light worked fine on the others. So here we go again I ordered yet another ECU out of a 94 SC300 M/T and put it in last night. So the car runs on 6 cylinders now but it is so insanely rich it tries to kill itself barely will idle(sometimes won't) and then smokes like a freight train from raw fuel. So all I can think is yet again another bad ecu. Since the previous one ran fine on all the cylinders but 1. Now all cylinders and just runs insanely rich. Got so fed up with it I bought myself an 07 6mt IS250 for a daily.

grumpi300

iTrader: (1)

running insanely rich sounds just like the capacitors are bad. thats something that you should have rebuilt and not worried about having to replace it unless the motherboard is toast. just sent that one down to driftmotion or anybody that repairs ecu's of your choosing.