Missfire @ 4000 rpm in 2nd gear

[kinselma]

When driving at full throttle in second gear @ 4000 rpm check engine light comes on and I get a misfire. I let off and misfire lasts for about 30 seconds and then back to normal.
I just recently upgraded to granatelli coil packs. I have changed the plugs and still the same problem. Its putting out codes: P0352 P0353 P0354 P0355 P0357 P0358, Ignition coil B primary system fault. It does not do it under normal conditions only at full throttle.
Any Ideas???

[Richy04]

It Sounds like the Granatellis maybe arcing or one may not be seated properly.. etc.. Check the spark plug wells for oil or other contaminants.

Try removing them and checking them visually for cracks, wetness or contamination etc.. Even if they are new, sometimes defective items make their way into the box so look for defects as well.

They claim they are high voltage replacments and if they live up to that claim there is more of a chance for them to arc if liquids, cracks or any metal is in close proximity of the secondary circuit. When it comes to electricity, its not always a straight run from the source to the destination..

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In re-reading your post, I see you changed the plugs, it sounds as if one coil is arcing when at 60+ percent or more duty cycle, suspect a defect in one of the coils and look for arcing on the outside of the coil itself there may be a corona residue if its been doing it long enough.. The reason its not firing for 30 or so seconds after, is the affected plug is wet when you back off and it wont fire again until the plug dries up..

I would get it to miss again then check the exhaust mainfold runners with an infrared thermometer, chances are the missing cylinder will be slightly cooler than the others then begin looking at the coil for signs of arcing. Dont remove any plugs from a hot aluminum head but if you shut the motor down and wait til it cools, you may be able to see some wetness or unspent fuel on the plug in question.

Borrow one of those thermometers if you can and you will see a difference on at least one runner when its been missing for 15 seconds or more, that probably your best bet..

[Stranger in the Black Sedan]

Do you still have your stock coil packs to swap back on? I know the name Granatelli from my TPI GM stuff -- they make a replacement "adjustable" mass air filter that has been plagued with horrible feedback from people who have used it. I would be afraid to ever buy something electrical from them after their infamous TPI MAF, but that's just me. Hopefully you can work it out.

[Local Boy]

Here's an idea that helped me find where my ignition was arcing on my '76 Blown Bronco. This will have to done in a DARK setting (night time/no lights on). With the engine running and the coil covers removed...simply spray (spray bottle) water (light mist) over the coils and plug wires. The water (mist) will allow you to see where the arcing is located. Looks like small lighting bolts (blueish in color). You might need to rev the motor if there is no arcing while idling. Hope this helps... it worked for me...ALOHA