I have a 1997 XJ6 VDP that I bought a few weeks ago. At the moment, it is sitting in my driveway because when I start it, it runs rough and throws codes P0302, and P1313.

I know I need to swap coils to determine whether the problem follows the suspect coil on cylinder #2. I plan to do that as soon as we have a warm enough day, as I am in New England.

I am looking for recommendations on whether or not there are suitable aftermarket coils available. If so, where should I purchase them?

I've seen some posts here that say you should change all the coils at the same time. Is this really necessary?

How are the cylinders numbered?

Also, the Code P1313 says that the Misfire is bad enough that it could damage the cat. converter. Is it safe to drive the car, at low speeds, a distance of 4-5 miles to get it to a local shop?

Also looking for tips on what to do, or not do, while changing spark plugs and coils, as well as how to thoroughly clean the throttle body, and MAF.


Any help is greatly appreciated.

Thanks
Leo

 

Aftermarket coils can be good. We bring ours in from the UK and have had very good luck with them.

http://www.motorcarsltd.com/LHE1510AB.html


I personally don't think you need to replace all the coils at once. You will probably find that you will get the opportunity to do the others in short measure, but you can space them out as the problem occurs.

Nothing really fancy on changing the plugs and coils. I would pull the plugs prior to ordering parts and check for signs of oil leakage on the plugs. This would be a good time to pull the valve cover and replace the gasket and spark plug boss seals if you have leaks. This may also be what caused the misfire.

I'll leave throttle body cleaning tips for someone else. I would check into the gasket for it.

 

Thanks once again for the helpful advice Ken.

Do you think driving it a short distance will cause more damage?

 

No, you won't do any damage on a short run. You are recieving that message because the one cylinder is allowing raw fuel into the exhaust system. Prolonged running could have a very negative effect on the car. Running to the shop should be no big deal. Do not idle for a long time before you leave and don't stop to run errands on the way! I think you would be just fine.

 

Thanks again, man.

That is a big relief. It's way too cold to work outdoors.

Merry Christmas

 

Can anyone tell me if my coils are bad?

I have a 95 xj6 sometimes it runs perfectly smooth, then it will start running rough and misifiring, then go back to perfectly smooth. Does a coil cause a constant misfire or can it be OK then bad, then OK again?

Is there an easy way me or a mechanic can verify which coil, is bad? also if its not the coils what else could cause it to run perfecrt, then rough, then perfect a few seconds later? Bad ECU?

 

Yes, coil problems can come 'n' go.

If the misfire is bad enough it'll show as a specific trouble code as mentioned aboive....so you can at least isolate a specific cylinder and then swap coils to see of the misfire follows the suspect coil.

A coil can be easily tested but, of course, it has to be tested WHEN the car is misbehaving or nothing will show up.

RTLL

 

How can you test a coil?

 

Easiest way is to check the resistance with an ohm meter. If you want to get "old school" about it you can pull the coil, attach a known good plug to it, and ground the plug out as you crank the car and check for spark that way, however, if the coil issue comes and goes (common to have problems once the coil heats up) you would need to pull it rather quickly before it cools back down or you won't be able to replicate the issue. This is why I vote for the ohm method...much quicker to pull the harness and check the resistance quickly than pull the actual coil out

 

An easy way to check the coils is to loosen the bolts that fixes them to the valve cover and when the engine is running lift them up a bit. And you will here the spark going from the coil to the plug.

If the coil is begining to get bad you will here the spark is a bit softer or it wont spark as you lift the coil higher up.

No need to replace al the coils just the faulty ones. The coils fail on these cars but not so extremely often and it would be kinda stupid to change them all.. Maybe every coil exept from the faulty one has been cahnged before.. This is an extremely easy job to do you ned an 8mm socket and an t30 torx.

And as someone else said check for oil in the sparkplug wells.

Pardon my bad English...