Listers,


subject is my wife's 2004 s type 4.2.


Goes into RP mode immediately or soon after first drive of the day, engine runs rough.. This occurs whether or not car has been on maintenance charger (on board 1.5A, doesn't seem to happen when off the 2A charger). Code not always thrown but the times it has been, it P0305 or P0307. Second start of day, engine runs smooth, RP warning goes away.


Action taken so far:
Can of injector cleaner run thru system.
contemplating purchase of injectors for cyl 5 and 7.


looking for wisdom.


Brian Smith

 

Don't throw money at it.
Go to jagrepair.com and download a copy of the workshop manual or get a copy of the JTIS from the stickies and fault find it as the codes are saying you have a misfire and that may not be faulty injector it can be a coil or even the spark plugs.

So start by checking the spark plugs. Then swap coils around to see if the fault moves as well to another cylinder. Then you will have a better idea.

 

Quite likely bad coils so focus on them first. Swap/etc. If you buy any do not buy crappy cheap ones!

 

Update:

was able to get it to duplicate for me, car set following pending codes:
P0205
P0300
P1316

Reading my powertrain DTC guide, I'd say I have a #5 injector or coil going bad. Since it's intermittent, I would predict it most likey an electrical vs mechanical.

Thoughts?

 

Swap coil five with another one from the engine and see if the fault moves to that cylinder. This will show you if the coil is not working.

 

I agree - most likely the coil.

 

Coils most likely or spark plugs. A few weeks ago I had the RP problem due to some heavy rains / storm actually / and a bit of moisture around the coils.

 

Ok, this morning I drove the car, immediately went into RP, no CEL.
Drove to store, went I came out, upon restart, PR mode CEL illuminated, P0305 code
drove home, left car running, used long screwdriver as stethoscope:
Injector 7: ticking
Injector 5: no ticking
Injector 3: ticking
Injector 1: ticking
verified #5: definitely not ticking
shut off engine, restart engine; no RP, CEL lit
rechecked injectors, #5 now ticking

OK, so, replace injector #5?

Brian Smith

 

No. It may have shut it down due to a bad coil.

I suggest to take the advice given already. The PCM is trying to save the cat conv but so far you are not helping it do so. If the coil is the cause you do not want to replace a costly injector and continue doing damage thus maybe also need a cat.

 

Talk about leading a horse to water!

Brian, many posters made mention of switching #5 coil with a different functioning cylinder. Heed their advise.

 

+1 on this excellent advice from JagV8. Here's what a Jaguar training manual has to say about misfires:

"If a persistent misfire occurs, the PCM will identify the cylinder and switch off the fuel injector."

Your silent fuel injector may very well be a perfectly normal response by the PCM. Given the chance to spend your time and money, I'd simply swap the suspect coil to another location and see if the fault follows, as previously suggested.

 

Ya'll seem to be giving me such a hard time about swapping the coils around. My point is this, If I'm going to dismantle the car to swap the coils, and that's the issue, I want the replacement in hand. Being in rural Mississippi, I can't just flip down to my FLAPS and expect them to have a coil sitting on the shelf. So, I've already ordered the replacement, and, if that's not the issue, it can sit on the parts shelf JIC. Figure one is going to fail sooner or later, better to have the replacement on hand. I would rather dismantle and reassemble once. Just my preference. But I do appreciate your help and advice.


Thanks,


Brian

 

Hi Brian,

dont take it personally. We are only trying to help you save a few pennies from personal experience. These cars can be a very efficient bank account reducing catalyst.


I thought you have a 4.2 car and not a 3.0 v6 because with them you do have to dismantle a lot to get to one bank. If you have the 4.2 you should be able to get to it quite easy. As it could be a little bit of oil and not the coil.

 

A 4.2 is indeed easy to swap coils around.

 

Well if you are going to do that why not put in a new set of spark plugs?
Probably a enough miles to need them changed at this point?

It would help to have complete info because I don't know how many miles are on the car?
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I do have the 4.2. Looks like I have to remove the upper engine cover (no big deal)and valve cover to get to the coils.

 

I return to the well of wisdom, spanner in hand.....

Ok, I figured out for easy it was to swap coils. Results:

Swapped 5 for 3,

started engine, entered RP mode immediately

Misfire on cyl 5, so, no change

ran engine for a while shut off, restart, still in RP, shut down, restart; not in RP mode any more.

So, now what? I stand in the shadow of you council.

Brian Smith
2004 4.2
119,000 miles

 

Did you clear the code before you started the car because it takes a number of starts before the ecu (2 I think) sees that the fault is no longer there.

 

It needs warm ups (*), not just starts.

(*) at least 2

 

Well if you did clear the code and it did come back on cylinder 5 then that points to an injector or the connection to the injector or coil. Those injector clips are known for breaking. In fact you can purchase just the pigtail if yours is bad.

Any chance it's the clip?
If not swap injectors next.

Keep at it!
I would still put new plugs in with 119K. Get the right ones they are expensive.

Oh Happy 4th!!!
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