96 DOHC missing mid range HELP!

[Fieroking]

96 DOHC in Fiero 97 ECM no cat, iridium plugs, 8mm low resistance wires. Engine idles great but when driving or just idling rev the engine it stumbles and misses in the 3k rpm area. I have changed everything and checked the cam timing

Any Ideas Please!!!!
Joe Sokol

[Sloick]

96 DOHC in Fiero 97 ECM no cat, iridium plugs, 8mm low resistance wires. Engine idles great but when driving or just idling rev the engine it stumbles and misses in the 3k rpm area. I have changed everything and checked the cam timing

Any Ideas Please!!!!
Joe Sokol

is there a code? sounds like maf to me, but idle would suck.

[Fieroking]

Stumble mid range

No codes looking at the system with HP Tuners MAF is working. More info I have tried several other ICM's and the engine won't start even with a brand new ICM! Wiring, ICM, Ignition Modules, Ignition Wires???

Any Help I'am Stumped
Joe Sokol

[OldSkoolGP]

Last time I had that problem it was the coils. Do you have a spare set of those you could try?

[Fieroking]

96 DOHC missing mid range HELP!

This problem has me totally baffeled I have tried 3 other ICM's (won't run on any of them). I have 3 other sets of coils, I have not had it run on any of them. The one set that runs is the one that will not run over 5K and starts missing at just over 3K. I am going to start running through them again.

Any other ideas???
Thanks Joe Sokol

[Fieroking]

Found the problem! A search on the Fiero Forum lead me to the twisted pair running from the Crank Position Sensor to the ICm were reversed. As soon as Ireversed them the engine came alive. HOORAY now back to the dyno.

Thanks for the help
Joe Sokol

[HayesPerformance]

Something that is very good to do as well is to "shield" the crank position wires better then they do.
It just increases the accuracy of the signal and the fact that on the 3.4 dohc's the alternator and the charge wire is that close to the crank sensor wires.

Watch on your scanner before and then after at the crank signal and related readings and watch the difference.

Its just a small thing I thought I'd mention seeing that your already there.......

[pocket-rocket]

Keep the twists in it too. Or, better yet twist it some more. Twists is what helps network cable resist noise.

[ratrodder]

you have resource for makeing a new crank sensor harness, (plugs or new metal connectors) , one of the lose ends I have on my car diagnosing it, would like to make a new one for mine