another miss fire

2006KJ · Nov 3, 2010

well.. got my mustang.. washed the engine bay.. then replaced all 8 coil packs with the yellow accell ones from summit. 4000 miles later i have a misfire. Dead coil pack on #3.. switched #3 to #5.. and the code followed to #5. Replaced that coil pack with a new one under warranty from summit. Drove the car about 15-20 miles and now have another mean misfire and a flashing check engine light... so what gives? another dead coil pack? Is my SCT tune killing coil packs prematurely? Any advice would be great.

wmburns · Nov 3, 2010

Moisture gets into the spark plug wells causing the spark to leak out. If continues it will damage the insulator boot. The misfire will continue even after the moisture is gone.

Autozone make an inexpensive set of replacement COP boots. Clean the spark plug wells to remove any grit at the bottom. Regrease with silcone di-electric grease. That's a good place to start.

Do you have under drive pulleys? Sometimes UD's can cause misfire due to unstable CKP signal. Another possible cause is incorrect torque of the front crank damper bolt.

2006KJ · Nov 3, 2010

wmburns said:
Moisture gets into the spark plug wells causing the spark to leak out. If continues it will damage the insulator boot. The misfire will continue even after the moisture is gone.

Autozone make an inexpensive set of replacement COP boots. Clean the spark plug wells to remove any grit at the bottom. Regrease with silcone di-electric grease. That's a good place to start.

Do you have under drive pulleys? Sometimes UD's can cause misfire due to unstable CKP signal. Another possible cause is incorrect torque of the front crank damper bolt.

Im sure the spark plug and boots are clean.. .. cleaned and replaced all those 4000 miles ago and dont drive the car in the rain or anything. Very good place to start your correct and i will double check. I do not have aftermarket underdrive pulleys (sadly). I'll also check the tq on the front crank damper bolt.. but havnt messed with that at all either.

wmburns · Nov 4, 2010

2006KJ said:
washed the engine bay..

So you don't think that washing the engine bay could be a source of moisture?

If you don't have UD pulleys and you haven't done any work to the crank shaft damper, then it's not necessary to check the bolt.

What cylinder is currently misfiring? Do you have the original Ford COP's? Consider putting new COP boots on the original Ford units and use those to trouble shoot with.

2006KJ · Nov 4, 2010

wmburns said:
So you don't think that washing the engine bay could be a source of moisture?

If you don't have UD pulleys and you haven't done any work to the crank shaft damper, then it's not necessary to check the bolt.

What cylinder is currently misfiring? Do you have the original Ford COP's? Consider putting new COP boots on the original Ford units and use those to trouble shoot with.

naa i pitched those.. and the engine bay hose down was 6 months and 4000 miles ago. I called summit.. they are going to warrenty my 8 accel coil packs and credit me for them.. i'll put that credit towards some MSD coil packs and hopefully will have no issues with them! Thanks for all your help.

trombonedemon · Nov 4, 2010

Before you go buying Accel's you might wanna confirm that that particular coil is not being blown by a shorted wire, otherwise your gonna waste cash.

another miss fire

2006KJ

New Member

wmburns

2006KJ

New Member

wmburns

2006KJ

New Member

trombonedemon

Well-Known Member

Similar threads

another miss fire

2006KJ

New Member

wmburns

2006KJ

New Member

wmburns

2006KJ

New Member

trombonedemon

Well-Known Member

Similar threads

Privacy & Transparency

Privacy & Transparency