Frustrated and can't find a solution :confused:

[dem18]

I have a 96 Kia Sephia LS 1.8L... I don't have an engine light on. Changed the ISC Sensor, MAF sensor, Plugs, Wires, Cap, Distributor and Air filter. Also cleaned removed the throttle body and cleaned it.

Don't know why sometimes when the car is idle the RPM starts to spike down below the 500 rpms that it usually sits at. Almost as if a wire was making false contact and causing the car to missfire.

Any help is greatly appreciated.

Thanks.

[jcwit]

Did you gap the plugs at .028/.032? To large a gap will cause a misfire.

[dem18]

I gap them at .028 the first time and the misfire happened after about three weeks. But it only happened once or twice then go away then a couple days later happen again. Then I figured I would buy new plugs and replace and that helped for a while but then it began again once in a while. Now the car is doing something different, it acts like it is going to shut off dropping from 600 to almost 0. Then it slowly climbs back to 600 and it does not do it for a while. Wierd. I don't have an engine light on so I cannot figure out what to try next.

[ron1004]

Originally Posted by dem18

I gap them at .028 the first time and the misfire happened after about three weeks. But it only happened once or twice then go away then a couple days later happen again. Then I figured I would buy new plugs and replace and that helped for a while but then it began again once in a while. Now the car is doing something different, it acts like it is going to shut off dropping from 600 to almost 0. Then it slowly climbs back to 600 and it does not do it for a while. Wierd. I don't have an engine light on so I cannot figure out what to try next.

The Idle Speed Control valve wont cause a misfire, but can cause erratic idle - if it is the ISC you could try taking it off and cleaning it with carb cleaner.

[dem18]

I have done that. I think that I found the problem. On the Kia Tech site I found out that some 96 Kia Sephias produced from Oct. 13, 1995 vin numbers (KNAFA125XT5241493)thru April 26, 1996 vin numbers (KNAFA125XT5260145) where the check engine light illuminates and one or more engine misfire Diagnostic Trouble Codes (DTC) (P0300, P0301, P0302, P0303 or P0304) is stored in the OBD-II system diagnostic memory... Anyways here is the link if anybody might be having this problem.

http://www.kiatechinfo.com/TechInfo/...cu_no=22&page=

Basically two wires were incorrectly connected and they have to be swapped to correct the missfire.

Hope this helps someone!!!

[Lsixer]

Should toss in a new fuel filter when doing all that.