Had Bryan at PCMforless fix a problem for me a few weeks ago. Put the PCM in and couldn't get the car to start. He thought maybe it was a bad flash and told me to send it back. Got it back the second time and still the same problem. Car turns over fine but will not start. Bryan then sends me another PCM but still no dice. I have no choice to have it towed to a garage. The guy pulls codes that flag the ignition module, but everything checks out OK. He cleans some grounds, and finally gets the car to start, although it still cranks about 10-15 seconds before it will even catch. It only starts every 3rd try. And to top it off, my tach is inop. It's flagging the MAF, but everything's fine.

The strange thing is that the car ran fine (other than a high idle) before the PCM exchange. Having put 2 different PCMs in it makes me think that's not the problem. Any suggestions? Thanks.

Justin

 

something would lead me to believe there may be crap in the pcm connectors. i would pull the pcm, and look for any trash, dirt, grease, rust, water, bugs, etc.

 

That's strange..but I agree with Hotwire...check for dirty connections.

 

I did that about 10 times. Checked for any bent pins, debris, etc. Double checked all the wires from the ports too.

Any other ideas?

 

well, if it worked before you pulled the pcm, and it doesn't work after, tried a different pcm, it has to be in the harness somewhere. have you checked continuity, checked to see the pcm is getting the vats signal, checked powers and ground going to the pcm w/ a volt meter to see it's getting full voltage / low resistance on grounds? checked your key to make sure it's clean, checked fuel pressure, checked for spark??

It's pretty hard to diagnose something over the internet, get out under the hood man, it's about the only thing you can do. odd stuff like this, is only fixed one way.

*edit*

also noticed you had a 6btm. my buddies gave out on him, check that to make sure it's still firing. start eliminating possibilities.

 

Thanks for the input Hotwire.

Brought it to a garage and checked all the voltages, etc. No ignition and no pulse to injectors. Mechanic thinks it's the crank position sensor - there's no output coming from it. PCM wiring checks out OK. One of the plugs to the Opti (new in Dec) was corroded as well, but cleaning had no impact.

Does the crank position sensor sound right to anyone?
Thanks.

 

could possibly be that, have heard of them going out at wierd times.

Have your mechanic put the scanner on it and watch it as you crank the car, should tell you right away if something is wrong with it. Have you gotten any codes for the crank sensor?

Have you recently messed w/ the timing cover or anything in the vacinity? lol, checked to make sure it was plugged in and wasn't shorted or cut somewhere?

Is your maf hooked up? Intake tightly sealed to the throttle body? Any vacuum leaks?

 

When he turned it over there was no signal from the crank sensor.
Checked the opti/coil/MSD and everything is hooked up. MAF is hooked up and didn't raise any codes.
I checked all the ducting to/from the intercooler ( I had a problem with that a few months ago). I'm not sure if he got any codes from the crank sensor or not.

I definitely agree that there has to be one thing that will fix the problem. The thing that still baffles me is the fact that it all happened after I swapped PCMs. Seems like an odd coincidence.

THanks again for the feedback.

Justin

 

Well, some sensors are electronically sensitive, you could have popped it w/ static electricity or something like that.

good luck man, let us know what you find.

 

Well they finally figured it out. It was the damn Opti again. The thing that gets me the most is that I replaced it in Dec. Not really sure why it went this time.

Do these things typically burn out that quickly? Next time I'll do the Autozone thing and get the lifetime warranty, replace it myself and save $450.

Also had to put in a new cap and rotor - those ran $270. Are those things supposed to be that expensive? Last cap and rotor I bought for my 68 Camaro ran me $50 for an MSD set.

I'm officially on the "I hate the Optispark" bandwagon. When does the group meet and what are my annual dues?