Edit- If you don't feel like reading 5 posts of me narrating myself, jump to the bottom.

I was getting in my car to go to work. i recently finished a paint job. it drove home yesterday without any unusual problems. just the normal miss from an exhaust leak. anyways. it started up and idled just fine. as soon as i put my parking brake handle down, the headlights came on as usual and the engine shut off. fuel pump primes up okay. fuses all checked good tested properly with a test light. codes are p0106 B2 o2 sensor, p0300 random miss, and p0332 knock sensor. as far as i know, none of these codes would cause a no start. things that i've fixed lately: new maf sensor, 1 year old map sensor. car hasn't moved in almost a year so it's practically new. cooling fans were on a switch. returned to factory. The thing about the cooling fans is that while i was still working on the paint job (car had been sitting for a while) if i turned the switch on it would instantly blow the gauge fuse. that is why i put them back to factory. i don't belive it's fuel related because it ran for a bit before it died. i may be wrong but if it was the pump wouldn't it have either stumbled, or not started at all. I have an "autotap" diagnostic system for my pc. i'm not sure if i can datalog with it though. where should i start? i have limited tools. i wish this would've happened at work where my car has been for almost a year and since i have $30,000 worth of Snap-on stuff there.

 

playing around with my auto tap scanner i found out that i'm not getting any tach signal to my pcm. I would crank and it would read 0. guess it's time to start figuring out how to check the opti. i'm still open to suggestions though.

 

per shoebox's website. at the icm i have 11V on A and D to ground. don't have anyone around to crank engine, don't have t-pins to stick in terminals . going to opti jumper harness, i have 5.1V on A and B, good voltage on c, .674 Mega ohms on D. it appears if i'm reading everything right that i have a ground issue to the opti. does ground come from the pcm? which grounds should i look at first??

 

you guys are all going to hate me for having to read this. i found a friend and had them crank it. i saw no change on terminal b or c to the icm. i'm wondering and hoping though that my meter just doesn't update fast enough to see the change and it's catching it in the middle. so i either have a bad ground, bad opti, or both. right? it just doesn't seem right though. why would it just die that quick. usually when my opti's would go out it would take a week of crappy running before it would quit.

 

Depends what fails in the Opti. If the low res part of the optical sensor craps out, the crank will rotate 2 times and the PCM then shuts off the fuel system. If the rotor falls off, the effects will be immediate also.

But in the case of the cam position sensor, you should have codes for the optical cam position sensor signals. P0372 for high res signal and P1371 for low res signal.

 

no such codes. just the three listed. i also don't think a dirty ground would have caused an immediete problem, but i'm not sure on that.

 

Okay. basically. car won't start. i believe i lost ignition. i have no tach signal. i have too much resistance on the low reference wire at the opti connector to ground. i'm just wondering where the pcm gets it's ground so i can make sure it's clean. my measurement from battery ground to pin D of the opti connector was .674 Mega ohms. i'm pretty sure that's a bit higher that 0-2 ohms. i'll do a continuity check to the pcm when i get home from work and post results. as a side note. is there anything special to pulling the pcm out to unplug the connectors?

 

The PCM wiring diagrams on Shoebox's website show where the PCM gets its 12V and ground from:

http://shbox.com/1/4th_gen_tech2.html#1995_pcm_wiring

Do you have 12V between pins C and D? IF you've got 12V, you've got a ground.

 

silly me, i should have thought to try that. i'll check when i get home. thanks Fred