Hi all
my apologies if this is covered elsewhere…

I have a 1996 XJR recently fitted Andy Bracket.

I took it for a good run yesterday and noticed that in sport mode with my foot buried in the carpet, it upshift to the next gear at around 4300 revs.
I’ve screwed in the kick down switch behind the accelerator pedal all the way in towards the floor.
I’ve also ajdusted the cables under the bonnet (tc and throttle) to take up any slack, but then got a high tick over, so backed them off again till my idle is around 800 rpm.

can anyone advise me on how I can see my car reach the red line?

Many thanks

 

I suspect you have screwed the kick down switch in too far. I think it needs to be in kickdown to hold the gears all the way to the red line.

 

thank you. I’ll try winding it back out. Cheers

 

There was something about in sport mode it skips the 1 st gear on your GM transmission

 

vice versa

sport starts in 1st and normal in 2nd.
http://jagrepair.com/images/Training...s/200_1996.pdf (has lot of info about the workings of the auto gearboxes)

NORMAL Normal mode provides economy operation by causing the transmission to upshift at lower engine speeds and throttle openings. Start-off occurs in second gear unless the accelerator is depressed to the kickdown position. High speed performance is available as required. SPORT Sport mode allows the engine power to be used to its full potential at all times. Start-off occurs in first gear and upshifts and kickdown are tailored to performance requirements.

 

On the later models of X300s which does not include mine ( normally asperated 1996 VIN 755XXX with mine including traction control ) there is a throttle cable adjustment ( different cable makeup ) between the traction control actuator and the throttle body

There was some factory documentation on this cable adjustment posted in the past on this forum

I bring this up to say I personally would not touch this adjustment unless fully understanding the effects of this adjustment

It may only effect your idle speed which you are fortunate to have correct on your different SC engine and may not have any effect on your shift points

The document passed through contributor CDMA that I don't think is active anymore, but I may have it saved somewhere on my computer

The more common transmission on the X300 ( ZF4HP24 ) is a Bosch transmission ECU unit off my memory

There are 2 speed sensors inside your GM transmission and in the end you may be looking at a on the transmission body connector clean and someone did find his / her transmission ECU connector not fully connected

These 2 sensors should read the same fundamental resistance value compared to each other , and are inductors ( probably 1300 ohms )

The transmission ECU is behind the glove box almost to the foot fwd vertical wall on the very bottem , ribbon connector pointing down so easy to get to

 

thanks for all the info.
mine is also a 1996.

i have previously seen some workshop instructions on here that went along the lines of… “slacken off cables-measure 0.2mm on butterfly etc..”. But to do this looks like i beed to remove the supercharger elbow… ill be honest, im scared to do this.

thanks again

 

One check you can do easily is your shift points in the normal mode that would say somewhat your 2 speed sensors a functioning corrrectly

At 4000 Rpm the signal is a sign wave or square wave , at 5000 it is a more compressed wave that has more peaks per unit of time

A perfect signal can be discerned correctly ( or not ) and a imperfect signal or imperfect dicertion ...............

Grounds cleaning relating to the tramsmission ECU , there is a dedicated ground strap on the engine ECU

The transmission and engine cross talk on a wire as they dance together to coordinate their activities

There are a few Jaguar TSBs on you GM 80E transmission on your SC model related to shifting issues and the upgraded transmission has the Orange dot marking mentioned in the paperwork

I do not have the GM transmission

See section 8

JagRepair.com - Jaguar Repair Information Resource

 

Once you have tried unscrewing your kickdown switch so that you do actually enable kickdown and wide open throttle response, you might want to look at that idle. 800rpm is higher than ideal, especially in gear.

 

The limit may be the actual engine performance not reaching the shift point ?

Someone with the XJR in New Zealand had the throttle cable miss routed at the throttle body and not able to true wide open throttle

He has a film that you can compare the audiable