What product do you use to clean TB and map senser??

 

Quick update
Cleaned TB and MAFS again, made no difference. Going to try a can of BG44K next as Gus suggested [ might change the fuel filter first ]

Thanks for all your ideas

 

Working on the engine to solve the cold surging will not help, it is the TCM and/or the torque converter. There is a CODED reflash for the TCM that the dealer can install. It has to be coded from Jaguar to the dealer before it will download. If this reflash does not work, the TC replacement is the only fix. This appears to only affect ZF 6hp26 in the 03 XK range and the 04 XJ range. The XK got the 4.2 and 6 speed 1 year before the XJ and it is the 1st year models that have the problem.

 

Thanks for the info oldmots, but what throws me is that 'marsdan' has the same problem yet his is a 2006 model!

 

A converter can fail on any car, just the early X350s had the problem more often. X350s were sold in the UK in 2003 but not in the US until the 04 model year. The XKs got these parts in 03. The TC problem was dealt with half way through the 04 model year with a modified TC used. Another part of th eprobelm is the TCM adaptations, this is what the code reflash aims to fix. If the reflash doesn't work, the problem is the TC.

 

My car was surging at low idle after I had removed and cleaned tb connectors. I took the negative off battery and touched to positive to ground the electronics ( as per forum ) and surging went away as i guess the system needed a reset. of course its rare that such a simple fix works !!!!

 

Hope to find the answer on Sept. 4th. as its booked in at T.L. Jaguars.
Will let you all know the outcome!

 

SURGING FIXED
For all you people that have the same problem as me, 'oldmots' was correct with the 'fix'. Took my car to TL Jaguars in Wokingham who performed a coded 'reflash' and for now the problem has gone. Yippie!
Thanks for everyones help,
Keith

 

Kudos to you! On the road again.

 

Hi Maxwdg, I know your post about surging is from quite a few years ago but I must ask..... Did you every find a fix? I have a 2003 S-type 4.2L and have spent heaps of cash trying to correct the problem. The dealer software update probably made it worse. What I have been doing is starting off in 4th and then move it back into drive once warm... still not happy about it! Cheers... Dave. (JAG666)