Well lets just say this hesitation is driving me nuts. I have an 02 3.0 with approx 120k and I recently had a serious problem with a p0306 code and serious misfire issue. Thanks to this forum I was able to figure out that my imt o rings were bad, I heard the valves sucking in air. Now I have fixed the o rings and ran a bottle of chevron fuel system cleaner and I am still getting a slight hesitation. It's not nearly as horrible and I have driven the car about 300 miles or so and have not gotten a new code, its just enough to annoy me. I have checked the elbow at the rear of the intake manifold near the firewall and its looks fine. I have noticed that the plastic hose the comes from the "t" near the throttle body that goes into the passenger side valve cover was loose and had missing teeth that helps it stay tight into the valve cover. I have ordered this part however I do not know if this is enough to cause the hesitation. Am I missing anything else that might cause this? Any help would be appreciated, thanks in advance.

 

Ok, looks like I might have solved the problem. I forgot to mention earlier that I switched the coil from cylinder 6 to #5 b/c I was getting the #6 misfire. I figured that if I got the code p0305 then I would know that it was the COP. Well today I got the code p0305 so I figure that the COP must be the culprit, im going to try that out and see what happens.

 

Sounds very likely and well worth a shot. If you look in the FAQ I think it gives the cheaper Ford part # and you'll be able to get that type of COP quite cheaply online if you wish.

 

When I repaired my vacuum leak I replaced all the coil packs on that side and I will give you the reason why. When my son had the car one of the coil packs failed that were under the intake manifold, he had that one replaced and he replaced all the plugs. I since then I acquired the car and a vacuum leak at the same time. I identified the leak under the fuel rail using CRC TB cleaner. When I hit the spot the car began shacking to the point of nearly stalling. In the process of making repairs to the vacuum system I elected to replace the coil packs on the one side and new plugs on both sides. I had it apart and it was the right time. From what I understand the coil packs for these cars have a high failure rate and felt the time was right. I did get the coil packs from NAPA and they work just fine. I will provide a link to my repairs http://www.gusglikas.com/AutoRepair2...VacuumLeak.htm I hope this helps!

 

Thanks guys for the responses I am going to do the side under the intake manifold soon and upon doing so I will change out all of the coil packs and plugs and anything else that will need changing bc I know that taking off the intake manifold is a pain in the butt, I dont like to do double work. Thanks for the link on the ford COP's that will work with the Jag, that will definately save me some money. Much thanks to this site for helping solve the problem the car seems to be running fine as of today. Keeping my fingers crossed.

 

Gus your write up on the removal of the intake manifold to change the plugs on the passenger side is exactly what I have been looking for a million thank yous. Btw what gaskets will be needed for the removal?

 

I hope it helps! As for the parts necessary you will need the gasket set for the intake and the fuel rail and the elbow. I got the gaskets from Jaguar but not sure if you can get them from Ford. I did get the elbow from Ford. I got the coil packs and plugs from NAPA. I would suggest pushing for a discount; I did it with Jag, Ford & NAPA and got it. You will never know until you ask.

 

I have recently purchased an 8/2001 S type 4 Litre.
It has 88000 klms. I have all records of service since purchase, and the following are supported It has had new spark plugs new coil packs fitted in last 6 months all other servicing is all up to date oil is Castrol full Synthetic since 15kklms
Does not have any Timing chain issues now or in the past.Have done about 800ks since I picked it up 2 days ago.
I have a missfire under load between 1700rpm under light load, if I give it max throttle it will accelerate normally , the engine light will come on for about 1 min then goes out.
The car runs smoothly at all other times. Will cruise at 140-150 absolutely no trouble.
I notice there is a slow running correction tube that needs unblocking, which has not shown up on any service record, is this a possible cause?????
Any sensible suggestions appreciated.

 

Should have read between 1700 and 2000RPM.

 

Is the check engine light flashing? That is a very bad sign, warning of catalytic converter overheat and likely internal damage.

Whether on steady or flashing, there should be a diagnostic fault code set. Do you have a code reader or scanner? If not, some parts stores will read the codes for free. Get the actual 5 digit code (P0301, for example), not just the definition they give you.

And what is a "correction tube", and how do you know it needs unblocking?

 

The Correction tube is the subject of a Jaguar Service notice.
I dont have access to decoder at present but called the guys who have serviced it from day one. The light flashes for about 15 seconds then goes out and for the remainder of the day virtually does not come on again. I had a theory it may be because the car has not been given a long drive for about 5 years . If I accelerate hard over 2000rpm it will not come on. It is only on extremely light throttle.
I will get it onto a decoder when I get home.
The description I gave the Service guys, did not think it was critical!

 

treat yourself to an Elm 327. These are a very cheap obdII interface tool. The last one I bought cost 14 Euros. I personally use the WiFi version as it can be conne

 

Well it will have sooner or later and will write off the engine. Changing the relevant parts is optional if you don't mind risking that occurring.

 

A further installment on my issue.
I have arrived home some further 550klms, no more issues, I read the owners manual which tells me I can run it on 95 Unleaded with ethanol at 10% which I did . Then got to desperation stage with no 95 Unleaded available so had to put 15 litres of 91 Octane to get me to a 95 octane station. Rather than just fill up with 95 octane decided to fill up with straight 98 octane no ethanol! 100ks down the road hesitation has gone no more lights flashing totally smooth , can push the accelerator to the floor no hesitation just goes. I have kept putting 20 litres of 98 Octane in it, to ensure I was going to get through all the unleaded ethanol mix. The only thing I did notice was from time to time a very faint smell ,which I think may have been the Catalytic converter burning of the ethanol. I intend to buy myself a decoder ,I have to buy one online as I am not in a major city. This info may help others ??????????????????????????????
No signs of destroyed engines, in fact I think it is running smoother and more sprightly than when I picked it up! Just my sixpeneth.

 

I fully intend to pull the front off the motor and replace all the timing chains slippers and tensioners.etc.
Dont suppose anyone has done a kit to change to double row chains ?

 

Yes there are timing kits available just google it. You will have the choice.
Have you downloaded a copy of the JTIS (jaguar technical information system) it is available from the forum. this will tell you how to strip the engine and replace the timing chains and tensioners. From what I understand it is not the chains that were the problem it was the plastic tensioners.

The elm327 will read all of the engine codes and only costs about 14 € from amazon. I would personally buy a WIFI version as you can use it on a laptop and smart phone

 

I know that single row chains are readily available, as I mentioned I was wondering if someone had manufactured a conversion kit to all double row chains.
I have watched and downloaded the technical details, looks pretty straight forward, but sometimes what you see is not what you get.?
Thanks for your interest and suggestions.

 

not sure if there would be enough space to fit a duplex chain but this firm may be able to help you.
THE JAGUAR AJ-V8 ENGINE / AJ6 Engineering

 

Not sure why the question is being asked. The chains are not the problem.

 

I had misfiring issues and did diagnosis after diagnosis (months worth) until, by chance, I swapped out batteries b/c of amplifier drain. Problem solved!