95TS 3.8L Misfire REVERSE ONLY

[Jeffrv]

Update here..problem solved I think! 12V power wire to MAF sensor was broken internally, causing intermittent. Wire broken just where wire exits 30 pin connector, on engine side of harness. Squeezing wire bundle there caused engine to run really rough, wire replaced, running good now

[500hpgtx]

Really glad you found the fix Jeffry!

My grand prix is a year 2000. OBDII obviously. In the past, when I was doing modifications to the engine, I ran into problems with high idling, possible vacuum leaks, etc. An easy troubleshoot tip I used was to unplug the MAF and drive the car. The PCM switches to stored parameters and the car can be driven, albeit with low performance. I also keep a spare LS1 MAF.
I do not remember if I tried it with the Series 1 engine and OBD1.5. I know that I have replaced the MAF in the past on our van.

What a relief to get that solved right?....cheers KEV

[LMP]

So simple after the fact.....check this out

http://www.automotiveforums.com/vbul...d.php?t=389188 ....jump to last post by canaris

http://www.automotiveforums.com/vbul...d.php?t=635459 ...(ahh..reference to same story above)

[500hpgtx]

It is amazing to me how well these 3.8L engines run when nothing is wrong.
I have left the rear large 40 pin connector floating in an upright position because of possible several wires broken at the connector. The engine idles and runs so smooth that you almost think it is not running.
A Pontiac trans mechanic friend told me that they switched to a new wiring some time ago that is much more "limp" than the old days because of these problems.....reminds me of when I used to convince hospital labs to trade in their old stat blood analyzers for the newer CPU controlled instruments. The old instruments had some real nightmare broken wire issues due to flexing from sliding in and out an antiquated printer..old nightmares..cheers KEV