After tune up my 1998 xj8 Rough low idel stalls

 

Welcome to the forum Rdojr,

I've moved your question from General Tech Help to X308 forum. Members here with the same model will be able to help.

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Graham

 

What was done for the tune up?

 

Just replaced plugs.

 

You might be missing some sparks then. I would check for good electrical contact in the ignition coils and that everything is plugged in correctly. Make sure the correct spark plugs were put in with the correct gap.

 

Plugs came pre gap. I was very careful with them even double checked the driver side. Reason for tune up number 1 plug drive side fouled out due to oil.

 

Check to see if there is gas at the exhaust or if it smells like too much gas. If there isn't any spark, then the fuel will not get burnt and will be expelled out the exhaust valve and into the exhaust system.There are several ways to check if you're getting spark. One way is taking it out and checking if it fires, but I don't have much experience there. What were the symptoms before the tune-up?

 

I think it should be driven more. Parents only take it out about one a month or even longer. Before tune up was running great About two weeks ago less then a mile from home started to run like hell they got it home. Next day I stared it and it I knew it was a bad plug so when I checked first plug it was full of oil. Tryed to check for spark the old fashioned way buy taking it out and starting car for a second to check for spark did not see any "but not to sure about how well that went I'm not at all formiluar with the coil packs". But could see needed new plugs.

 

The plug was oiled (the electrode end in the bore) or the plug recess in the cylinder head was full of oil?

If it's oiled, there's a problem with the cylinder bore/piston rings allowing oil 'blow by'.

Oil in the recess is a regular issue usually caused by failed camshaft cover rubber gasket or 'O' rings. Less often it is the result of a cracker cover. This does cause misfiring when the oil reached the coil pack.

Graham

 

Just the top of plug was with oil below where the pack plugs into plug. I cleaned all oil out before I replaced plug. Only the first one was really bad. The next 3 on same side not even close to first. Seemed the further from the first the better they got passanger side no oil on any.

 

Car no longer runs like it's missing a plug just the low rough idel now. Could the coil pack be misfiring? I did not mix them during tune up?

 

You will need a code reader to determine which cylinder or cylinders are misfiring. Without that, it's guesswork.

I've deleted a number of your posts on this same topic from other forums. Do NOT multiple post the same question. This is the correct place for technical questions about your model.

Graham

 

Ok, and Thank you. I will try a code reader tomorrow. Is there a chance driving with a fouled plug could throw off timeing?

 

No, but you could damage the catalyst.

 

The big risk with a misfire is unburned fuel getting through to the catalytic convertors which can rapidly destroy them.

Graham

 

Hope today we can troubleshoot my parents car. I really hope to get the easy do it your self suggestions dune before I get into anything to technical. So please help me figure out This rough low idel on 98/xj8 Thanks.
Richard

 

Have you checked for codes yet? It's hard to troubleshoot without information. Local auto supply stores will read codes for free.

 

Just Tryed to get codes pocketscaner says no link. So I'm on my way to try and rent a better one

 

Just Tryed to get codes pocketscaner says no link. So I'm on my way to try and rent a better one

 

Just to be clear for you:

- If there is oil on top of the sparkplug, it is most likely caused by leaking sparkplug seals, allowing oil dripping in the hole.
Fairly common problem on our cars, and can be solved by replacing the various seals after lifting the covers.
Seen various cars soaked in oil, but not seen major problems caused by that.

- If the oil however is on the sparkplug nose, that's an other story ...

If you say a fouled plug, I should suspect a faulty ignition coil, which should show up as a code.
Just move the faulty coil over to an other cylinder, and see if the fault follows for confirmation.