Hello everyone, I have an 2004 x type that is really starting to have an acceleration problem after driving for a short time. It started to be an occasional thing but now it is getting to be a normal issue. It starts choking out when you accelerate and the engine doesn't even rev. We replaced the in line fuel filter and that seemed to help for about 2 months but now it's worse than ever.

 

Matt, welcome to the Jaguar Forums. I think you will find that there will be a lot of very useful information here on the site. But, we do ask a simple thing from you. Please stop by the "New Member Forum" and introduce yourself. Like a Jaguar, we try to uphold a higher standard. This will also give you a chance to meet the movers and shakers of the site too. Who knows, you may even get a small surprise while doing it. So, grab a cup of Joe, sit back, do some reading and go from there.

As for your problem. I would start first with a visual inspection of the plug on the side of the throttle body. See if you spot any exposed wiring. The plug in question is on the driver's side of the throttle body. The wiring there can get damaged and cause various issues. Next, remove the inlet air tube and using a can of throttle body cleaner (not carb cleaner, there is a difference), if you see brown, spray it away. Make sure to open the butterfly valve (the silver disk in the center that blocks the air) and squirt the edges too. Odds are, this will flood the car out if you do this, but it is easy to overcome. Simply put your foot to the floor on the gas pedal and start the car (forces the computer to not admit gas to the engine surprisingly enough) and after a few cranks, the motor will fire and you can then back off the gas pedal and feather it to keep the engine running. Then lets see what you have at that point.

If you are still having issues, it may be that the sensor on the gas pedal is bad and the computer is not picking up the fact that the gas pedal is being depressed. Otherwise, you should be getting a check engine light that is saying there is a mismatch between the gas pedal and the position of the throttle body. So, if you are still having issues, let us know and we will give you a few more things to check.

 

Sorry about not properly introducing myself (I did know better) I definitely will try what you suggest, it sounds reasonable. I'll keep you posted.

 

I echo Thermo's statements. My car regularly requires cleaning of the throttle body, the MAP sensor (the little unit, just upstream of the throttle body) and the various connectors on the throttle body.

I also find that I need to lube the throttle body shaft, as mine gets stiff over time.

I use spray cleaner and a toothbrush on the TB and just spray cleaner on the MAP sensor. I also make sure to push open the throttle plate and clean the edges and the bore.

As for a special throttle valve coating, mine never had any sort of coating. It's just metal.

 

I have the air filter/intake off right now and going to get some throttle body cleaner. (That thing is filthy!) We'll see how this works. thank you all.

 

That's it! That did it, I cleaned the throttle body and took it for a "longer than normal" ride, revving it like I stole it and it didn't give me any troubles. Thank you for your support, that thorn in my side is now gone.

 

Matt, good to hear that you have that issue resolved. A lot of the problems that our kitties have are easy fixes. I am sure a shop would have gotten you for a lot of money for something that you can fix yourself. I would still recommend cleaning the MAF sensor. It is easy to do and should help with any other minor issues that you might be having.

 

haha, actually, I'm heading to a friends professional shop next week to use some specialty tools so I can fix my MAF sensor. Something crawled under the hood and chewed the wires clean off!!! So that will be like new anyway.

 

Just cleaned my throttle body and maf outta boredom... Lol, running smoother and for sure worth the 8 minutes or so that it took