What's up fellow org members. I need some opinions on a slight miss I'm getting when my car is hot. Seems to happen more often now that summer is here and the temps are up. Here's whats happening.

At a stop, engine idling A/C usually on I can feel a complete misfire of what feels like one cylinder. It sort of feels like a hickup. This is happening every so often, not all the time. My gas mileage is great, no codes from the ECU either. I've got 81000 miles on the clock, all the maintenance is up to date, NGK plugs ect.

My first thought is a coil pack is going which I've already had happen. But I get no ignition error codes. Last time a coil pack went I immediately got a CEL along with the code pointing to the cylinder at fault. The other option would be a plug thats not good. The ECU cannot detect a spart plug thats gone bad. But again as I've mentioned my gas mileage is great, power seems good too even with the A/C on.

Think I should just wait and see if eventually the car throws a CEL? This has been happening for about a month now. I'd hate to be on a trip somewhere and have a coil pack or plug fail on me.

Realizing the 99's are notorious for their coil packs, I'm leaning twards replacing the remaining 5.

Any advice would be appreciated.

 

Unplug the #1 coil pak connector and see if the idle changes. No change = bad pak. Change = not the coil pak. Do the same for the injector connector if you can get at it.

 

i've got the same exact problem.... my thought is coil packs... mine haven't thrown a CEL but when I tested them, 1 came up with a pretty low ohm reading, so I think that one's going out.

 

Exact same problem here, 95 SE w/ 123k. After I noticed it I put in all new NGK copper plugs, and didn't notice it again for a few weeks. But then it came back, so I'm not totally convinced it was a plug. I think it may be either an intermittent problem with a coil that wouldn't set off the CEL, or an injector... any other ideas?

 

I'd say coil pack, my wife's car ran like that for about 3 months before it finally triggered a code. Replaced the defective coil pack and car ran well again for about a month, then the same thing started to happen. Make a long story short, ended up replacing the remaining 5 coil packs. With your car being a 99, its most likely a coil.