I have an issue. After installing a new motor I found the negative PCM wire attached to the starter. OOPS!!! Yes it we tried to start it about ten times before stopping to check. When I changed it back over to the block the motor started. It runs real rich at idle, haven't driven it on the street yet. I had PCMforless tune it and was wondering if there is anyway to check the PCM before sending it back off to Ohio? With that being said, does any know of a good tuner? I didn't get the love from Keith I thought I should have and I haven't called him about this yet!

Thanks,
Barry

 

Not sure what can happen when batt voltage is applied to the PCM ground buss. If the car starts and no SES indicators then PCM is basically 'working' . A data log or scanner would be need to analyze why it appears rich to you. Sounds like you had some other work going on that required that ground lead to be disconnected and re-connected. Anything we should be aware of ? Most tuners will do free retunes, if the initial tune needs tweaking. But they need data logs to work from. Not sure why you are saying send the PCM back to Ohio. Is it returnable or exchangeable ?

 

There is more than one negative power wire to the PCM (4 actually), going to two different locations. Only one of which is normally near the starter. If that one had 12v applied (I doubt that) it would have blown a fuse, a link, or that wire right away.

 

Barry, I was assuming the black/wht ground wire was incorrectly attached to the purple wire (starter solinoid). Is that correct

Gary, The blk/wht goes to PCM pins A2/C32 the purple wire is feed by TDR/ignition switch/and fusible link E. Purple goes +12 when key is in start position. Since car starts fusible link is OK. Could short have melted the wires to PCM as they are only 16 or 18 Ga, or something on the PCB. Or are the grounds separate in the PCM. If the A2/C32 pins (block terminal ground) are bussed together in the PCM to the A18/D1 pins tan wires (front of left head terminal ground) then that would be a batt to chassis dead short. Something would have to open up.. W/O a log we are guessing if and why it's rich..

 

The PCM internal grounds are all tied together on one bus. The extra wires are for redundancy and to keep the wire size reasonably small for the type of connectors used.

 

Thanks for the help guys! I had the car running with open headers and Keith from PCMforless told me to put it back together and try running it again. I didn't realize that would mess with the O2 sensors. I hope to get it back on tonight or tomorrow and take the car for it's first ride.

Thanks again!
Barry

 

Ok, took it for a ride and it ran like crap! First starting out it seemed to run ok then after about a half block I stopped at a stop sign and it died. It did restart but popped and chugged all the way back to the house. No ses light. Would a cat tuner tell me if the PCM was fried?