2005 XJ8L - When I park the car and then restart after approximately 10 minutes the engine starts to idle very rough...so rough that it ends up dying after about 10 seconds. If I try to step on the accelerator, the engine is VERY hesitant to respond, but once it does rev is seems to clear itself and runs okay from that point on. The problem does not occur if I am away from the car for only a minute or so. I receive no CEL and no pending codes exsist.
What I have tried:
*Ran a bottle of heat through the tank thinking it might be bad gas - same results.
*Ran a bottle of BG 44k through the tank thinking it might be build up related - the problem appeared to be resolved for about two fill-ups. The problem reoccurred with my current tank of gas, I think that roughness of the idle has lessened after using the BG 44K, but the issue still exists.
*Replaced the air filter - Replaced during the current tank of gas

Did changing out the air filter have any effect on the MAF senor? Any other thoughts what might be causing the issue? Run another tank of BG 44K?
I appreciate everyone's time and help!

 

This problem sounds like a problem with a leaking fuel injector. I suggest getting them tested for operation. Applying the throttle changes the pulse width and the injector clears itself. The longer it sits, the more the fuel puddles in that cylinder until the pressure in the system is dropped unitl the leak stops.

 

Also make sure you throttle body plate isn't gunked up at the edges...its supposed to have just a tiny gap, many times it gets carbon buildup on the edges, and after a heat cycle, it can stick....tapping the pedal gets more fuel to the rail, but electronically controlled, if the butterfly is stuck still, it'll die.

 

I am having the exact same problem. It started about a week after I bought my '07 VDP. I took it to the dealer becuase it has the certified warranty. They said the Mass Air Flow sensor was bad and replaced it under warranty.

The problem came back and I took the car back to the dealer. The computer had two pages of codes in it and no one was sure whether they had been cleared at the last service a few weeks prior. They cleared the codes and told me to drive the car for a few weeks to see if the problems persisted and if the codes came back.

After two weeks I had the car at my independent shop for its 50K service. (Problem was still there) I had them check for codes and found misfires in two of the cylinders, a miscelaneous misfire and a misfire in the first 1000 revs. I took the car back to the dealer again yesterday and they confirmed the codes, but suggested that I just run two bottles of BG44K through the tank. Leaving at least one clean tank of gas in between the first and second bottle.

Car hesitated and died on me today on a hot start up while going to the autoparts stores trying to find BG44K. I can't find it anywhere.

I will keep updated if that helps my problem and interested to see what you find out.

Anyone know where I can buy BG44K without ordering online?

 

I have a couple of extra cans available, but I would suggest a full induction cleaning.

 

Thanks for all the ideas guys.

A couple questions from the submitted ideas:

If a fuel injector was leaking, wouldn't it be leaking on a consistent basis and not intermittent?

ALLDATA has a service bulletin for this engine to NOT clean the throttle body. If the plate is gunked up - how is it to be cleaned?

Since the BG 44k seem to decrease the roughness, I think that I am going to try another tankful and try cleaning the MAF.

 

Leaking injectors are caused by crud in the pintle, it can move around and change characteristics, it may act differently under different conditions. I once had an injector that would only misfire under minimum pulse width (idle). When the engine speeded up and the pulse width increased, it worked fine...the devil to find that one. Just trying to save you some time.
How many miles are on the car?

 

Oldmots,
There are 65k miles on the car. I will definitely mention this to my shop when the car goes in for service next month. I appreciate your explanation on how this might be causing the problem.

 

BG44K is sold at many car dealers parts departments, just call a few.

 

BG Findashop - Search for an authorized BG service center near you!

 

I'd like to chime in and give a little more perspective on this elusive and frustrating symptom, that seems to plague some owners while others never experience it. This has been popping up more and more frequently as time goes on, and I am convinced it is directly related to fuel and fuel blending. It does have to do with injector 'crud' as one gent put it. Yes it can 'come and go'. One instance a few years ago I couldn't prove it on a given car that I suspected, until I ran the car, brought it in and quickly removed the fuel rail and watched the injector tips. Nothing. Did that five more times, on the fifth trip one injector dripped like an eye dropper.

After several years trying to get a handle on this we have noticed patterns. Here in the midwest, the occurrences seem to be few in the summer, starts to escalate in the fall, peaks about this time of year, [mid March] and trails off into summer. Most people aren't really aware of it but in our region the fuel is seasonally blended. Blending for winter in this region begins in early-mid November and ENDS this week or next, when the summer blending returns. We have notable increases in both this starting roughness and misfire faults recorded when we're on winter blended fuel. For some reason the 2005 model year is by far the worst. I have a couple of 2005 owners who have the routine down, CEL in winter, records misfires yet no problem at all with performance, just a CEL. They come see me to turn the light off at the end of March and they are good for the summer. I'll add that the engine management system changed for 2006 and later, so the symptom profile changed a little.

For the OP, no CEL even with the rough starts is basically because monitoring is not initiated immediately after start up to 2005. In 2006, the new engine management DOES watch misfires immediately, in fact it has it's own fault code, P0316 Misfire During First 1000 Revs after Engine Start. That's why 2006 and later cars see the CEL more often with this symptom.

Now, what to do about it. In consideration of the owners time and pocketbook, we try to attack this in steps.
First, we recommend the BG44K. It's something the owner can do easily and the majority get rather good results. Some here can attest to that.
Second, and of course a bit more expensive is the perform a chemical cleaning of the fuel injectors. That involves disabling the fuel system and running the engine on a cleaning chemical run through the injectors. We use Valvoline VPS Fuel Rail Cleaner, used to be called SynPower, same stuff though. Some facilities use a Wynn's product, BG also makes one. I have gotten the best, most reliable results with VPS.
Third, is to actually remove the plenum and injectors to send for professional cleaning, flow testing and balancing. We send them to Linder Fuel Injection Service, lucky for us they are on the west side of town here locally. They are nationally known as one of the best in their business.
As a side note I'll add what transpired with them recently. We sent them a set of injectors, and of course sent them with directions we wanted the aforementioned cleaning, flow testing etc., and the rough warm starting symptom. They did the work, and called to tell us that based on their testing they DID NOT THINK THEY WERE AT FAULT for that symptom. We thought, well what are we gonna do now?? Long story short, we reinstalled the freshly cleaned injectors and we've had no more reports of the rough start from the owner.

So you see, it's frustrating for us as well, because we have to try to fix the car while keeping the expense as low as possible, and not being perceived as incompetent because the first [or second] recommendation may not have panned out as we'd hoped.

Now, all this has related to our midwest REGION. Fuel is REGIONAL. That means this sort of thing plays out again, sometimes differently, in other regions/countries/climates.

Brutal! You lurking?? What can you add regarding your warmer climate in TX??

I hope that help some.......

 

My 2006 XJ-8 is doing the same thing!! Starts and runs great, but when I come back after the car being shut down for a few minutes, like a quick stop at the store, starts and idles very rough?? I'll try the fuel injector cleaner, about 48000 miles on my car.

 

Thanks for the detailed input Steve!

 

FWIW - The local Chrysler Serv Mgr has a radio show. He has mentioned several times that the amount of alcohol contained in local gas is quite variable and often has a higher % rating than allowed for good running characteristics.

Just for grins, why not check the alcohol content. There are cheep kits avail in the auto parts store. It may be worth a try.

 

Excellent point! See, there is just so much to be mindful of when diagnosing late model vehicles. I keep a graduated apothecary cylinder handy to do just that. For us, E85 is a curse.

Cheers,

 

I should have mentioned that I am not a fan of BG44K. I used it once and it fried the O2 sensors in the car immediately. I now shy away from all mouse milk products and just fix the offending part. In this case, the injectors need cleaning by a pro. Most manufacturers tell you not to use additives, and they are right.

 

I guess we'll have to agree to [partially] disagree.

On the merits, I agree with you. It would always be nice to jump to the last step and be done with it. But everyone deserves the opportunity to take a chance and possibly side step a higher expense. Just like gambling, sometimes you make out.......sometimes you don't.

On the O2 sensor thing, which vehicle did that happen to?? BG44K has been run through a whole lot of cars to date that I know of, and no such issues have resulted. I can sure bet if Jaguar had any reservations they would not advocate it's use in their cars. Especially the new 5.0L, direct injected and every one still on their nickel??

My two cents......

 

I've had the same experience with fuel additives as oldmots. Once on a 2000 Buick and another on an 05 Dodge truck. Within a week of adding a fuel system cleaner, don't remember which brand, an oxygen sensor failed.

While the above didn't exactly cause me to swear off fuel system cleaners it did instill an abundance of caution. I now use Techron exclusively, not more than once a year, with a full tank of gas and only on an all day trip.

I'm sure there are other safe and effective fuel system products, such as BG44K, but I think I stick with what I knows.

 

I had the problem with a 96 Ford Probe GT. It was obviously the cleaner since the car only had around 30,000 miles on it and both sensors went out in one day. I never used cleaner again but maybe time has made the stuff better, I'll never know. I send injectors to SD Faircloth in Florida. He's a Jag Forum poster and has a real good turn around. The fastest way to get horsepower is to get the lost original power back (around 20 % in most cars). A key to it is cleaned and matched fuel injectors. This can help make a draggy car feel like new.

 

I wanted to give everyone an update. I finished running two tanks of BG 44k and the problem still exists....
Today, I received a CEL with the following codes: p0300, p0301, p0303, p1316, p1111

Looks like I'm going to have to be more aggressive and have the injectors cleaned and inspected.