CarRacer has knock issue

[steve]

posting for CarRacer

Hey fellas,

I have a 91 Galant VR4 with a running issue.

It has a 1G 7 bolt and it hasn't run much in the last year. I've slowly been working on it and I'm almost done, but need a little help.

I've recently upgraded to 750cc injectors, 3G MAS, and Keydiver chip with proper compensation for said parts. I also installed an Aeromotove FPR as well.

I just got the ECU hooked up after installing the chip and fired it up. Car idles like a champ rock solid at 950rpm. No stumbles, burbles, or misses. When I touch the gas the knock counter boost gauge pegs and the car dies.

I called a buddy in CO, and he helped me narrow it down to the MAF(I think). I can unplug the MAF and it won't idle but it revs fine. No misses.

I recently bought a different adapter harness to replace one I had that might have been suspect with no change.

I don't have a logger, as my palm batteries died and I can't upload anything to it as I just bought a house and everything I own is in cardboard boxes. I'd love to fix the Galant and start to daily it, so I can sell my VW and put that cash into my house. I just need a kind soul to help me with this small issue.

If someone could help me, I'd happily provide gas money and dinner on me. The car is in Prior Lake. It's at a fully appointed, heated shop. As I'm currently using my iPhone and this site is very slow, contacting me through email is faster. I'll still check here, although not as often. CarRacer AT Gmail DOT COM is my address.

Many thanks for reading and hopefully you guys can drop some knowledge bombs and get me pointed in the right direction.

 

[toybreaker]

I would visually inspect the knock sensor.

When they get overheated, the potting compound melts out.

This may make it overly sensitive. /ubbthreads/images/graemlins/dunno.gif

 

ya those knock sensors are crappy when the 'goo' melts out of them. +1 on replacing the knock sensor. I have the same setup as him and i run 20psi with 0 knock all day. It might be some crappy gas but my guess is on the sensor.

 

[Rausch]

Home skillet will report back when he gets a logger/gets his functioning again. We are thinking he still has some wiring issues/maybe a bad MAS....

He gonna check the KS in the interim though. /ubbthreads/images/graemlins/smile.gif

 

[CarRacer]

Got the logger hooked up and had VRausch4 on the phone.

O2 sensor might be wired incorrectly. I was seeing zero volts at idle and it spiked to 4 volts when I applied gas. So I might have crossed the heating wire and sender wire. Whoops.

The ECU "clicked" rapidly when it did it's knock shitfit, so that might be an issue. It read 243 counts of knock, 4v o2, and 1600kHz Karmann when it does it's thing. So possible ECU issues, but it might be caused by suspect o2 and MAS wiring.

I'm going to try and get the car inside and get a tester on the o2 wires. I'm going to also trace the MAS wires and double check that.

I'll report back with results.

 

Those are awfully wacky readings. Make sure he hasn't popped the sensors ground inside the ECU by miswiring something. Pin #24 of the ECU is the sensors ground, and should read almost 0 ohms to ground, pins 101/106 of the ECU. If you miswire the O2 or MAS it pops open a trace, and none of your sensors are then grounded and the voltages are way off.

 

[CarRacer]

FIXED!

With the help of two wonderous people on the board my car is fixed.

It turned out that the MAS wiring I "fixed" with solder and seal connectors was the problem. Evidently I had gotten a little over zealous with the torch when melting the solder and burnt the insulation away. When I used convoluted tubing to cover the wires, it pushed the exposed bits together, causing a short. After soldering in the pigtail that Toybreaker sent me, it ran fine. My heatgun is at my house, so I couldn't finalize the install, but the car runs.

Thanks again to VRausch4 and Toybreaker for the long distance assist in getting another Galant back into the fray. :clap:

 

[Rausch]

No more threatening to cut the blue wire(s) now, huh? /ubbthreads/images/graemlins/rofl.gif


You get an O2 sensor yet?

 

[cOmpressor]

Quoting steveVR4:
1G 7 bolt



^ Glad your problem is fixed but what's this about?