98 2.5L misfire at low RPMs

[metolent]

Hi all - I've been searching around, but haven't found an exact description of what I'm experiencing. I have a '98 2.5L that seems to be misfiring at low RPMs. It's happening more regularly (well, over the last two days). No CEL is coming on and it stops as soon as the RPMs increase. Moreover, it's a bit intermittent as it doesn't do it every time at low RPM, but it does seem to be getting worse. At higher RPMs, it's fine.

I changed the plugs and oil tubes about two years ago, but didn't change the coil-packs. Thoughts?

thanks,
matt

[blue62]

Originally Posted by metolent

Hi all - I've been searching around, but haven't found an exact description of what I'm experiencing. I have a '98 2.5L that seems to be misfiring at low RPMs. It's happening more regularly (well, over the last two days). No CEL is coming on and it stops as soon as the RPMs increase. Moreover, it's a bit intermittent as it doesn't do it every time at low RPM, but it does seem to be getting worse. At higher RPMs, it's fine.

I changed the plugs and oil tubes about two years ago, but didn't change the coil-packs. Thoughts?

thanks,
matt

How many miles on the car??

Do you have any test equipment??
like a......
Digital multi meter??? OBDII scanner???
Vacuum gauge???

Always start with the simplest things first.
Then work through the issue step by step in a logical progressive manner.
So pulling your plugs and checking there condition (color) would be the first step for this type of issue.

Color=condition of the plugs can help you determine if your having random missfires over all cylinders or just one bank or just one cylinder. that can be important information.

What is the condition of the porcelain on the plugs? Clean? dirty? oily?
Again that is important information. oil or dirt on the porcelain can cause issues..

Then the condition of the coil packs.
Then the wiring.
Let us know what you find.
Most issues are usually something simple.

Oh and very important if your not getting a "CEL" how do you know your getting missfires????

[pilot4fn]

Could be also that one of the wireing connection clip to the coilpack has worked it's way loose or maybe one plg has become a pit loose.

[metolent]

Yep, you were right. Pulled all the plugs and coil packs this weekend and while the plugs were fine (all looked good), several of the coil packs needed replacing. Replaced all plugs after checking all gaps before installation and replaced all coil packs and she's back to running like normal at low RPM. Thank you!

thanks,
matt