Throttle link. What is the mid mechanism for?

X300
#1

Hi Guys

My car is an Aston Martin DBS, but it has the engine of a 1995 X300 XJR(6). This conversion was by the previous owner. I am after more information about the mechanism found in the middle of the throttle linkage. I have no knowledge of what it is, but I presume that it is to tell the ecu the position of the accelerator peddle. But, as you can see some adaptation has been made and I don’t know what the mod is or does. Also there is what appears to be a motor as part of it, but I can’t think what that is needed for. To add interest, the ignition system is from an early XJ40. This was (he told me at the time) because the X300 ignition is so integrated into the ecu and linked to the inbuilt alarm system that to use a points & rotor arm set-up is much simpler so I don’t know if this throttle cable assembly is actually doing anything. There is even a switch on the dash board to raise the revs for cold starts. If it was something to do with ESP traction control (I don’t know if the X300 hid that, but it is not operational on my car for sure). All a bit Heath Robinson.DSCF0275|666x500

Any help much appreciated.

Thanks. Andrew

#2

A picture would be infinitely more useful to answer your question.

#3

I did add a picture - just after where I say “a bit Heath Robinson” it’s; DSCF0275 try clicking on it. Maybe I added it wrong, but it works for me.

#4

Holy crap, I’m out. Interested to learn what it is though.

#5

Well that’s two of us then :slight_smile:

#6

That is the TRACTION CONTROL mechanism for the THROTTLE.

#7

Ahh. That makes sense - except, This car has no working traction control. It is very easy to spin the rear wheels in 1st, often unintentionally when leaving a junction, and I once got a big ‘tank slapper’ on in second when I was a bit heavy on the pedal. I have no contact with the guy who made the conversion, but he was obviously very experienced and I’m sure wouldn’t have carried it over for no reason. In fact the top seems to have a home made adaptation to it, the red section on the top seems to have been added. Is that original to this unit I wonder? I suppose I’ll have to get it’s functionality investigated by a proper specialist when the car is back together. The Jag specialist who serviced the car when it was on the road said that it would benefit greatly from having an ‘Emerald’ ECU rather than the standard Jaguar one. If I go that way then perhaps I can get the traction operational.

#8

The original traction control actuators have a black plastic TPS (Throttle Position Sensor) mounted on the top. They are EXPENSIVE and it was likely replaced with a different unit?

I believe all the SuperCharged cars came equipped with TC and the throttle cable is very different than the NA cars. ‘Carrying-it-over’ might not have been for the TC to function but simply to get the throttle operational.
The ABS module is different for cars with TC so maybe the ABS module is ‘EXCEPT TRACTION CONTROL’ and the TC unit is not plugged in or operational?

#9

Thank you ‘Motorcarman’, that all sounds very plausible. I will have to get the system tested when the car first hits the road. If it is not possible to re-instate the TC the it may be best to dispense with this unit. It may well be that it was easier to carry it over in rather than find a new throttle cable. I want to make the engine bay as tidy as possible, but would like TC if at all possible. We shall have to wait and see what can be done. At least I know what it is now.

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