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Real bad idle

2480 Views 30 Replies 6 Participants Last post by  colorado zq8
I just changed sparks plugs and camshaft actuator silioniod and my truck will barely idle.had a cel before that was constant on and now it flashes.Took out for a short drive and it is way down on power.
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What kind of spark plugs? Did you gap the new spark plugs? Is the idle worse now than before?
Did you drop any of the new spark plugs?

Get the code read and let us know what it is.
If you purchased Iridium plugs and gapped them you may have damaged the Iridium. Or a coil pack is not properly seated.

If you can't track down what the exact cause is, put the old plugs back in and start over.
Flashing CEL means a misfire. Pull the codes so I can point you where to start looking.
The spark plugs are ac delco iridiums,,I didn't gap them.I read some where they are already set at proper gap.I will take the coil packs off again tomorrow to make sure they are seated correctly.I put the dialectic grease on the end of the coil pack.Is that where it is suppose to go or did I need to remove the rubber piece.
Oh good. Good move not to gap them.
You have a good plug, product type should not be the culprit (unless you got a bad one).

I think the #1 coil is the most challenging to have reseated properly. Maybe start there first.

I've never removed a coil on this type of system so I'm not sure how to answer the dielectric grease question.

Good luck.
Thanks 08canyon.
How much dielectric grease and exactly where did you put it?

I wouldn't use dielectric grease except a super-light film, just barely enough to feel it on the tip of your finger, applied as a film to the inside of the opening in the coil-pack.

Dielectric means it doesn't conduct electricity.
You only want a tiny smidge to prevent the rubber part of the end of the coil-pack from sticking to the end of the plug.
You do not want it all over the plug's metal end.

Same thing with anti-sieze grease on the plug threads.. barely any at all, almost none.
Thanks Rick crew,I put it on the end of rubber,that might be my problem.I put more than just a light film.I will pull all coil packs and remove it and pull sparks plug to clean them off.I appreciate the help.
What would be good for cleaning the dialectic grease from the spark plug.I was thinking of useing rubbing alcohol.
I'm sure alcohol will be fine.
Probably just wiping it off with a clean shop rag would be good.

You may have other problems causing the rough idle, but an excess of dielectric grease is not good.
Thanks rick
Happy if I can help.
May be as others posted, you just didn't get the coil seated right.
Or possibly the coil-pack or one of the coil connectors was damaged?

I hope you find it without too much trouble.
Post the results here so others can learn from your situation.
I will post my results.Thanks
I just got through cleaning the spark plugs and the copper electrodes and the truck is idling a lot better.I still have the same problem I started with.The truck will idle at 500 rpm then surge to 700 rpm.A constant up and down.
Alittle more info,the idle would surge before but it was at lower rpm.It would drop down to 300 rpm and throw a cel.Just wondering if it could be o2 sensors
You may need to perform a crankshaft sensor relearn after you installed this new exhaust camshaft actuator solenoid or at least disconnect the battery and short the terminals together to rest the pcm adaptions.
Have you tried to sea foam your truck? Quite simple to do, needs 2 people to do it properly and it fixed my idle when it was fluctuating like yours is.
Thanks guys
Freeballin I disconnected the battery with the ground and hot together.
Ststefan,I have sea foamed it before with no results,I might try again.Thanks
My guess is you still need to perform a crank sensor variation re-learn procedure with a GM Tech-2 because your low idle speed and flashing check engine light is a very common problem after replacing a defective solenoid.
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