99 GMC how to reset PCM?
05-05-2007, 01:54 PM
I have a 99 gmc and it started stalling intermittently about a month ago. It has since had a FP and filter installed..no fix, Then plugs,wires,crank sensor,dist pickup,ignition module,coil and a used PCM. Now wouldnt even start anymore, So while pulling my hair out I decide to reinstall the OEM PCM and it fired up! It was running rough but no less..running. Thought regulator problem..installed new fuel regulator. No change. Thought bad injector, so I bought an assembly on line..fuel poured out of metering block??? Put old back in now wont start again?? I have spent a lot of time and money on this and I feel it will be something small and stupid but If someone could help me I would greatly appreciate it. Just in case..FP is 58-63 psi, power going to coil and module, signal coming from crank sensor. Put another new module on..no difference. I would like to try to reset the PCM and see what that does. Thanks for any help you can give me.
05-05-2007, 02:47 PM
Do you have spark at the plugs, will it run on carb ccleaner sprayed into the intake, you need 65 psi to start this engine btw.
05-05-2007, 06:49 PM
Fuel Pressure good (right at 65 w/starting) , no spark at plugs. Got voltage at Module and coil, also pulse from crank sensor. But still no spark?:banghead:
05-06-2007, 08:40 AM
Lots of problems with coil wires on that engine put a known good one on . I assume the dist is turning?
05-07-2007, 03:10 AM
Dist. is turning, will p/u coil wire today and try it.
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