No spark on CYL 1 and 4

[dragrush]

Out of nowhere the engine started to misfire...later found Cylinder 1 and 4 have no spark but 2 and 3 do.

While driving the tach was acting a little goofy...seemed to read lower than what it really was. Driving on 2 cyl might of had something to do with it

While turning the key in the ignition, it doesn't always turn over (starter does not spin)....all I hear is a buzz in the dash, dont hear the CAS make any sounds

If I turn the key fast/repeatability it will start, but of course misfire. Not sure if the starting issue is related, cause it was doing that for about a week before the no spark issue

New plugs/wires gaped properly. good coils. everything is plugged in
Not throwing any codes

Im thinking power transistor or CAS
Any one know from these symptoms that can help me pinpoint the issue?

 

[housegsx]

My guess is power transistor. Mine used to do it when it was warm on a long highway cruise.

 

[BIGBLAZE79]

Mine has done the same and it was the power transistor. Out of the blue started running on 2 cyl.

 

[SlushBoXRacer]

yup power transistor for sure. . take it off and see connections have a white film on them, they are not repairable and are a little over 100 bucks at the autozone.

 

[slow4g6392tsi]

Where is this power transistor located? Sounds a lot like a problem I am having.

 

[ulitka]

Where is this power transistor located? Sounds a lot like a problem I am having.

On a 2G it is bolted to the runners of the intake manifold between coil packs and the throttle body, between fuel rail and the plenum of the intake manifold. The harness connector is about 2" wide with 7 wires.

 

[Calan]

Based on what you said, I think you have something going on electrically that may have fried the power transistor. I wouldn't be surprised if you replace it and fry the new one as well.

 

[dragrush]

Thanks for the replies everyone...I fixed the problem...it was a cracked wire in the harness to the coil pack.

One more question now.
There is a wire I accidentally broke off and cant fix thats on the coil pack...it goes to a little black box connected on one of the coils...anyone know what that part may be for? Or know what Im talking about Is it necessary, seems to run fine without it.