Rough Running

marko96 · 11-08-2006, 11:57 AM

Hi, My 1997 Sportage has suddenly decided to run very rough it does clear above 2000rpm but is noticably down on power i have changed the spark plugs but this has made no differance whats next check the coils? if a coil breaks down does it affect both spark plugs that it supplies or can it just affect one? compression check after that? it does sound to be off one cylinder.

Damkia · 11-08-2006, 02:32 PM

Quote:

Originally Posted by marko96

Hi, My 1997 Sportage has suddenly decided to run very rough it does clear above 2000rpm but is noticably down on power i have changed the spark plugs but this has made no differance whats next check the coils? if a coil breaks down does it affect both spark plugs that it supplies or can it just affect one? compression check after that? it does sound to be off one cylinder.

For clarity, is yours a single overhead cam or double overhead cam?

What sort of plugs did you put in, and was it playing before or after you fitted them?

There have been instances (quite a few) where Bosch +4 plugs cause the engine to misfire. Not recommended for this engine. Go the original spec NGK's, there is nothing to be gained from anything else.

Do you have the "Check Engine Light" on, or flashing? Have you read the error codes (if any)? If you post them here we may be in a better position to help.

TroubleCodes.net- engine & OBD2 Trouble Codes and Technical info & Tool Store.

If a coil goes it will usually cause both plugs to misfire, unless it is something on the outside of the coil pack (ie cracked plastic one end)

If you decide to do the coils anyway, replace the leads as well, and then at least you know everything should work properly. (saves pulling it down a third time.)

marko96 · 11-09-2006, 07:53 AM

Hi thanks for the reply, the engine is the DOHC version it was running rough before the plugs went in (NGK plugs)I am just going out now to check the coils apparently there are two sets of windings in each pack so i think its possible that only one side could go down without affecting the other i will let you know how i get on, the engine light is not on.

skier · 11-18-2006, 09:57 AM

Hi Did you get the problem sorted as i have the same problem.

Ranger · 11-21-2006, 02:51 PM

I've had to replace both coils in my 2001 Sportage in the last few months. The boot or "link" (the part which connects to the plug directly under the coil) went bad on the coil. However, you can't buy just the link, you must buy the entire coil. You could see the small hole in the rubber boot. At first I thought it was only a bad plug. A new plug would last about a day before it started working bad again. Changing the coil fixed the problem right away.

marko96 · 12-02-2006, 08:35 AM

An update on this problem i have replaced the coil packs with known good ones i have checked the cam timing it was ok i have unplugged all the electrical connections but the problem still persists the engine light is not flashing which makes me suspect something mechanical, burnt out valve perhaps has anyone had this before if so what are the symptoms?

mgbgt1972 · 12-02-2006, 11:42 AM

If you suspect a burnt out valve you should do a comprsssion test. Esay to do, you just need to acess the spark plugs.

What about your timming belf, sliped a tooth?

marko96 · 12-03-2006, 06:49 AM

I have checked the cam timing and it is spot on, i removed the filler cap whilst it was running and there is noticable pulsating pressure out of the oil filler hole, i dont have a compression tester so i will take it to the garage tomorrow and let them do a test, i am already on the hunt for a second hand cylinder head, the good times just keep on rolling in!

skier · 12-06-2006, 11:41 AM

I still have the same problem with my Kia. No warning lights on.Runs ok above 2000 revs but can feel like it is runnning on 1 cylinder at times below 2000 revs.replaced spark plugs,checked compression (ok),high fuel consumption. have ordered new coils.
The air intake pipe from the back of the engine is loose and sometimes comes out.could this be causing a problem?
air filter not been replaced for 10k could this cause a problem?
Any suggestions would be much appreciated.

marko96 · 12-06-2006, 02:20 PM

I have just had the compression tests done and all is ok the mechanic then checked the spark which is ok then on to the injectors two of the injectors were very weak the other two were flooding out, he reccomends new or secondhand injectors, but surely its what controls the injectors thats at fault, can anyone enlighten me as to what that is?