blk87Turbo2

iTrader: (23)

This is in my build thread, but I felt it warranted it's own thread.

The car had a weird stumble/hesitation in 3rd-5th gears at higher rpms (3500ish on up) under load and in boost...which is new since I did all the stuff in my build thread (link in my sig). I think it might be related.

I drove the car to a friends house so we could do a little driving and to take some pictures. When I got there I shut the car down (using the "WOT rev, shut off at 3k rpm" trick to prevent flooding) and walked up to his door. He met me at the door and we walked back out to the cars. I got in and went to turn the car on and got nothing...except the headlights popped up. They didn't turn on, they just popped up. No lights (except dome and door lights), no gauges, no radio, no tail lights, no head lights, no reverse lights, no BAC coming on...NOTHING.

So I checked all of the fuses (both engine compartment and cabin), they're all good. I checked all the grounds (top of engine under IC, underneath the coils on the shock tower, and main battery ground at the bottom of the shock tower), they were all good too. So I pulled back the carpet, pulled the ECU plate and checked the ground near the ECU, it was good. I also checked the battery terminals and they were clean and nice and tight. The only thing I didn't try was jumping it off another car, because we didn't have cables. It's on the "To Try" list for tomorrow.

Now my car is sitting at my friend's house tonight while I try and research what is going on with my car so I can fix it tomorrow. It's a good thing I'm on leave or I'd be pissed about not having my car working.

Any ideas?

Thanks in advance.

blk87Turbo2

iTrader: (23)

Forgot to mention, the hazards work as well.

satch

iTrader: (1)

And does this car have the starter cut relay or not?

blk87Turbo2

iTrader: (23)

The head lights popped up when I turned the key on, and went back down when I turned the key off. As far as I know it has all the factory relays (all four on the radiator support and the horn relay inside). All the fuses are definitely good.

satch

iTrader: (1)

The starter cut relay is located next to the main relay and is found in cars which have the factory alarm option. Does this sound like your setup?

blk87Turbo2

iTrader: (23)

I dont think the car has a factory alarm. It doesn't have a security light or anything like that. I wouldn't think an alarm would kill everything though. When I turn the head lights on, they pop up but that's it, the lights don't actually come on.

blk87Turbo2

iTrader: (23)

Car definitely doesn't have an alarm. I am only getting .4v at the ignition switch and nothing at the single connector next to the cabin fuse box.

blk87Turbo2

iTrader: (23)

More info and correction to the last post.

When the ign switch is off I get 12v at the switches B+ terminal. When I put the switch into ign1 the voltage on B drops to 1v. When I put into ign2 it drops to .06v. When the headlight switch is plugged in I can hear a relay inside click on and off when I turn the key on and off.

When I bypass the ign switch by jumping the B terminal across to any of the others nothing new happens, which tells me it's not the switch.

blk87Turbo2

iTrader: (23)

Made some more head way.

When I run a direct wire from the battery's positive terminal to the ignition switchs 'B' terminal everything works as it should. I measured resistance between the battery and the B terminal on the switch and I get 20ohms, which is really high, about 10x higher than I would expect. I get the same resistance at the ign sw plug when I unplug it, so definitely not the switch. I bridged over the main fuse with 10g wire and that didn't change anything. So what is causing all the resistance and ultimately keeping the sw from working properly?

blk87Turbo2

iTrader: (23)

One stupid, old, corroded butt connector (the old type where two screws go into each end of the wires). I'll post a pic of it and the final trouble shooting steps when I get home.

So happy. Maybe this will help the stumbling hesitation too...we shall see.

blk87Turbo2

iTrader: (23)

Here is the little guy that was causing the problem:


So the troubleshooting went like this:

Checked voltage at the ignition switch. Noticed a huge draw down in power when the ignition switch state was changed.

Measured resistance between the 'B' lead at the ignition switch harness and the battery positive terminal it came out to 20ohms...much higher than the 1-2ohms that it should be.

So I moved it to the next logical stepaway from the positive battery terminal, the front connector on the MAIN fuse. 20ohms, no change.

So I moved to the rear connector on the MAIN fuse. 20ohms, no change.

Followed the wire down from there and found this little connector, measured resistance from one side and it was 20ohms. Measured resistance from the other side and it was 2ohms...BINGO.

Cut the wires on both sides. Had to trim back a little on one side due to corrosion. Inserted jumper wire to replace the connector and checked operation of the ignition switch, everything is now working.

Soon as I can get the car back to my house I plan to solder and heat shrink the jumper wire in there and call it good. The kick in the pants is that I've noticed the sorry state of this connector before, but procrastinated replacing it since the car was running fine. That'll teach me, lol.

Hope this is helpful to someone else in the future.

Osirus9

iTrader: (10)

Very good advice. Glad to hear you figured it out, I have some electrical issues as well and they're just a bitch to troubleshoot.

blk87Turbo2

iTrader: (23)

For the sake of completeness...This did not fix my high rpm hesitation. Going to try grounding the boost sensor, but that's a whole 'nother can of worms.

Osirus9

iTrader: (10)

unfortunately for your hesitation, I was experiencing the same thing and grounding the boost sensor didnt do anything.

I never really solved this issue completely, but I could minimize it by adjusting the TPS ever so gently. Seriously, I was barely brushing the adjuster with a screwdriver and it would make my hesitation go away for a while, and then it would slowly come back. Just something to consider.

lots of trial and error... get the TPS in spec. test drive... hesitation. adjust the TPS a tiny bit. test drive... less hesitation. adjust the TPS again...

Also, the TPS was "in spec" throughout this whole process, so there is a difference between getting it "in spec" and getting it actually working properly.

blk87Turbo2

iTrader: (23)

I'll deal more with the hesitation in my build thread...and after I get my RTEKed ECU back, so I can data log.