Running rough after new spark plugs
 

I had new spark plugs put in my 01 v10 excursion and now it idles rough and when in cruising down the road it feels like its kicking. ( Meaning the cylinder is on its way down and then it fires) It dosnt seem to be missing and there is no codes coming up. I talked to the guy who installed the spark plugs and he said he gaped them. I pulled and tested each coil with a new one. Any suggestion would be great!!!

It didn't idle rough before the spark plugs and i used the stock replacements you would get from a dealer. Does great under a load pulling a 26 foot box trailer with 4000lbs in it. I can barley feel it when i have a load but i can tell its still doing it.

Cylinder is on the way down when it fires? .......never heard that one:-missingt

Meaning The spark is late and im getting a burst of power from a cylinder because the piston is not traveling the full distance. Thats what it feels like. I honestly don know.



I thought the timing was off but i took it to a shop and they said they you cant do timings on these trucks. Is that true?

That's true and this has nothing to do with timing. Whoever changed the plugs did something wrong or maybe a boot is bad. If they didn't change those you should start there. I believe it is missing if it is "kicking".

So i should probably switch out the spark plugs one at a time till i find the culprit.

Is it true you cant adjust the timing on them?

Maybe check the connection to your CPS. It could have come loose?

Sorry what does CPS stand for?

CPS=camshaft position sensor. It's on the front of the motor, driver's side. Follow the path of the serpentine belt between the alternator and PS pump...more closer to the alt. from the middle. There should be a black plug with a wire attached stuck in the aluminum block.

Most likely it's not it, but won't hurt to check connection. This sensor detects the position of the cam and tells the correct coil to fire. If this sensor is bad, the engine won't start. A loose connection could wreak havoc.

Good luck.

Gotcha, I will definitely check that out ty!!!

Timing is not your problem. Listen to your exhaust to hear if it is missing at idle then unplug your cops one a a time while someone is watching for fluctuations in the tach. The boots should have been changed unless it was done very recently.

Sorry, it's more near the bottom of the valve cover on the front driver's side as seen in the photo. Sorry AlaskanEx, had to grab one of your pics from the other post.
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[quote=jh818;10482352]Sorry, it's more near the bottom of the valve cover on the front driver's side as seen in the photo. Sorry AlaskanEx, had to grab one of your pics from the other post.
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You stole his picture! just kidding, actually that's a great shot and I always wondered what it looks like there. It looks like the sensor is between the belt tensioner and the idler pulley, is that it?

No, the other side where it looks like there should be another idler pulley, but it's not there.

Wrecker411, when doing spark plugs, the rubber boot (connects between the plug to the COP (coil over plug)) should be replace and the inside should be coated with dielectric grease. There is no spark plug wire, the boot acts as the insulator. If your mechanic did not replace them, and grease them, he should have.

Did your mechanic give you the old plugs numbered so you could see the condition?
How did you test the COP's?

When the boot is reused, small cracks in them will allow the charge from the COP to escape and ground to the engine block before the charge gets to the plug, thus causing a misfire. From what other report, it will not throw codes for quite a while and you will see other symptoms first (bucking, wierd shifting). Do the easy stuff like replacing the boots first.

Also, consider a computer reset. With the new plugs in, it could still be trying to run the truck like it had the old plugs. To reset the computer, disconnect the battery for 30 minutes. It will run on a standard cycle until it "learns" if it needs to compensate for any errors/motor issues. It takes a couple of duty cycles for it to re-learn with the new plugs once you reset the computer.

While replacing the boots, you can check the COP's at the same time.

PS: There is no timing adjustment on these, unilke older engines. The timing is advanced by the computer instead.

Sorry, I was thinking you said passenger side.