I’m having a rough idle and it doesn't go away... When I first start the car it runs good for the first 5 seconds and then it starts running bad again, and it does not go away.

The first time it did it, it had a: 301, 302 codes. So I went ahead and swap the Coils in Cyl 1 and 2 with 3 and 4, also I replaced ALL of the spark plugs and started the car again. Check for codes and it only had a P0352 B coil.

So I did check over and over for loose connectors in the Coils and nothing. So far I've decided it could be the ECM, so I sent it to GOECM.COM in Texas, and they just called me back with a diagnosis... They checked all the Ignition Circuits and modules and it they’ve all checked Okay. So they don’t think is the ECM.

I've searched in Google for Jaguar Coil issues, everyone of the threads I find discuses how they replaced all the supposed "bad" coils, but the problem stays, and NOT one of these threads has a solid answer on “how they've solved their problem”. In other words nobody bothers to write back in their threads "How" they've finally got their cars fixed. Too bad they don’t do so, since it happens quite often, I've found at least 5 threads and in all 5 there are no concrete solutions.

So I've decided to start this thread and once I get the car running I'll post the solution, so if anyone ever has the same problem, they can just try my same solution.

 

*bump*

 

Details? See:

 

The car is a 2003 STR and it has "NO" vacuum leaks, and new spark plugs. I've swap the Coils and nothing seems to work yet. The tech told me it could be the processor of the ECM... But the only way to know is to buy install another ECM.

Anyways, if I had another one I will know by now if it was or not. I found a used one from the junkyard, but if it’s not good (chances are). I can only get credit back ($150) in something else. But I don’t really need something else...

JG

 

It's almost 100% not the PCM. Last thing to suspect.

Likely the coil. Sure you've tried the right kind and in the correct place?

Possibly wiring.

No offence but vac leaks can be almost impossible to find and are very easy to miss. What are fuel trims at idle & 2500rpm?

 

Update! The ECM has checked Fine and no ignition Modules were damaged or burned. So I went back and started to look for a vacuum leak; I tighted up everything I could, and I've even replaced the gasket to the TB and the EGR, but nothing changed. I really dont think is a vacuum leak because if it was it will only manifest during iddle. But the misfire is present at all rpm.

Thus, today I went back to the Autozone to pull the codes again: P0300, P0302, P0304, PO306, P0308, P1314, P1316 and P0193. So something is wrong with all of the driver's side cylinders, and it seems that has to do with gas?

As a side note, I've actually gone back and checked the connectors for each Coil, but I've got a signal at only one pin of each Coil connector. I really dont know if I was suppost to get all 4 pins to light up with the test light? But like I said only one pin of each connector did.

Well something is not right. I really dont know what it is, but I will love to find out. I've even thought of the Crank sensor, but I really dont know what the symptoms are for a bad crank sensor?

If anyone has a wild guess at what is wrong with my car, please shine in, and give me your point of view?

Thanks,
JG

 

Study the codes PDF (see FAQs or JTIS), as it explains and gives possible causes.

Old-fashioned lights are generally a bad idea on modern electronics unless you're trained to know when they can still be used. You could easily cause serious damage where none existed.

BTW, be careful never to over-tighten. (Not saying you've done that, just a heads up.)

With so many codes for the same bank you're looking for what's common to that bank's cylinders but not the other bank. You could have an air leak, but something such as fuel rail is maybe more likely - or wiring. The elec diagrams are in JTIS and Jaguar electrical reference

It's hard to see how it could be the TB as that would affect both banks. Ditto the MAF.

It could be worth studying fuel trims (LTFTs) on both banks and at idle & 2500rpm to make sure your they're OK.

That IP code may be the answer. (See the codes PDF I mentioned.)

 

UPDATE!!! (Sorry I didnt have a computer for the last two weeks...)
Okay, I finally got it fixed! It was a wire in the #2 Coil connector. For ever I thought this was okay. I've tried it in two different occasions to (gently) pull the wires loose away from the connector. But none of them ever came off, and for once and for all two weeks ago I was so ready to give up; thus I bought a Coil and went to replace it, so as I took the connector out the wire finally came out. I guess the silicone piece that goes around the wire to keep the water out of the plug was very very tight, to the point that the even though the wire was broken it will not come out loose... Well as I promised I was going to fix it and share it with everyone. I really dont like how so many people starts their threads on their car's trouble and never come back to share the fix!

BTW thank you JagV8 for being there for me, and YES it was electrical.

JG

 

A fix - great - gotta keep these cars running!!

 

Amen!

 

Thanks for the info. This may come in handy should I have another misfire problem someday.
And with these engines it could be sooner then later.

 

Good too hear that you got her fixed. I ann having the same problems and codes. Did you ever have a strong egg smell ? Thanks for all the info, this give me a new light that I will fix mine as well.
rp

 

Good too hear that you got her fixed. I am having the same problems and codes. Did you ever have a strong egg smell ? Thanks for all the info, this give me a new light that I will fix mine as well.
rp

 

Egg smell ought to be H2S except there's hardly any sulphur (sulfur) in fuel anymore. It likely means unburnt fuel and the code hints at that too. Do the fix done in this thread / maybe get an OBD tool and watch fuel trims as in all the threads where I say this

Oh - see below:

 

I had the same problem/codes as in this thread. Turns out was two little nicks in the red wire to the connector causing short when coming in contact with the exhaust manifold. I wrapped the wire and put some flexible tubing around it, secured the wire to the air cleaner out of the way, cleared the codes and the car now idles/runs perfectly with no more codes. A $0.00 fix and didnt have to waste a bunch of time and money on new coils and swapping the around. Seems the hot manifold probably melted some of the insulation on the wire and then later the wire would come into contact with the metal manifold and create a short throwing the P0352 code.

Easy fix and really appreciate the thread here as it saved me!

 

Hi updip_geo,

Welcome to the Jaguar Forums! It's great to have you with us.

Thank you for your successful repair report - any chance you could post a photo or two showing the wire you repaired? You may have to get your post count up before you can upload photos - a quick way to do that is to Like some of the posts in the forum that you have found helpful.

Also, please visit the New Member Area - Intro a MUST and post a required introduction so we can learn something about you and your Jaguar and give you a proper welcome.

Cheers,

Don