Long time lurker here and love the wealth of knowledge in the forums.

I know there are many threads similar to this but I have yet to see one where the issue is the same as mine.

I’ll keep this as brief as possible -

~ I have no issues with my TPS. It sweeps from 12.9% to 94% when actuating the throttle by hand with no dead spots
~ I have no high idle issues
~ I have followed the technical bulletin on throttle cable adjustment using the two adjusters
~ I can not get any improvement over 65% when accelerator is fully depressed
~ Any further manipulation of the adjusters in any combination raises the idle

And now the interesting bit

~ If I remove the kickdown switch to allow for extra pedal travel, I do then achieve 75%, then I fall foul of the checkpoint in the technical bulletin instructions

~ The accelerator and throttle pulleys in the traction control actuator then separate and do not move as one ‘unit’

My instinct is that the cable is stretched beyond adjustment and I need to replace at least the accelerator side with a new cable. This looks to be still available. An alternative might be trying to shorten mine somehow to prove this out which I will research now.

Has anyone experienced this before?

Thanks in advance for any help!

Alan

 

I’ll also add to this that there is no visible damage to the cable outer at the traction actuator end, as I know this can cause issues. I have also done my best to lubricate the cable with silicone spray.

Lastly, with the adjusters fully relaxed I only have approx 30% opening so this adds to my thought that it is stretched beyond adjustment. The bit I am not sure on is the traction pulleys separating as the manual gives no further info on what to do if that happens.

I’ll take a few pictures and upload later.

 

I see your 94 % open reading

Do you have a mass air flow rate as someone in New Zealand with the SC had the cable run at the final TB bellcrank " off " before the cable end

Normally Aspirated : 175 grams / second

SC : 225 grams / second

These upper numbers are off the top of head reading from others

The mass air flow rate as an engineering rule of thumb 1 gram per liter displacement at 650 rpm and the normal idle speed for the AJ16 is Y so would have to extrapolate

The ELM - 327 live data reader can be off by a straight factor of 10 or 100 by a software error

The MAF sensor on paper will read 1.2 volts DC on the center wire ( color Y and Z ) at the proper idle as a confirmation cross reference

 

I don’t have any MAF readings, currently have the charge air elbow and a few other bits off. Plan to build it back up tomorrow so will take some then.

I have checked the routing and it seems as smooth as it can logically be especially the throttle end. The accelerator end it does have a sharp turn as it comes up to the traction actuator. RHD / UK car.

 

I've always questioned if a live ( not actuating ) TC restricts the throttle cable ...............maybe remove connector on the large TC actuator and not the TC position sensor on top ? and then observe results

 

My OBD isn’t great at recording multiples of live engine streams unfortunately and I didn’t have a helper to give me peak readings, so had to do it myself whilst driving -

Sport switched on, Trac off, peak engine load 78-80% in second gear at WOT. That was slowing to 30mph and using kickdown right up to full revs.

Important to note I was able to get more travel with kickdown removed but this is where the TC pulleys separated and I don’t know if it’s a good idea to do a WOT test at this. Logically I’m going to get some faults as there will be disparity between TPS at the throttle body and the TPS ontop of the traction actuator.

Given that the majority are able to achieve 90% opening at WOT I’m 99% sure my cable is stretched beyond recoverable adjustment. However I’m just after spending about 3K on a complete suspension overhaul so I’m cautious about working to resolve this now during summer and not being able to drive it when I should be enjoying it.

My only other thought is to shim the outer sheath where it goes into the traction unit to try and remove the inner slack, which could confirm the issue and then I can replace with a new cable over winter.

As always, any guidance greatly appreciated. The lack of info on dismantling the traction actuator makes me pretty cautious about launching into it.

Alan

 

Be careful on unwinding the cable on top of the TC actuator , not that it's spring loaded minus the spring on the return spring at the final bellcrank but is a mess to get back together

So.................... thoughts on removing the TC as it is a factory sometimes not on all option

The white sheath on the cable at the TC actuator is brittle so do not stress it

Going back to the throttle body " tower " that has the original throttle return spring , was it put back together correctly after the TSB done or not done . The person in New Zealand found his cable mis placed on the TB tower but can't recall detail

There is a work around that may have been done as the TSB uprated throttle return spring no longer avail , this involved winding the original spiral spring to a tighter preload clocking that there are pictures of as many have done

 

I’m guessing then to replace the accelerator cable it’ll be an advantage to unhook the throttle cable from the throttle body so you aren’t working against that spring.

Doing away with TC is a possibility, direct to throttle body would be much easier. A traction fault light is I’m sure guaranteed but the impact to ABS seems to be slightly unknown. The TC is pretty archaic these days as a system and this is now a good weather car so I will maybe unplug completely the TC and see what happens before looking at cable replacement.

Finally I could buy a second hand traction unit and a new cable and work on this at my leisure!

Interesting that a NZ car had incorrect routing, it’s a very short run but I will see how else it could be placed. Noted your comments on the TB spring, it’s very easy to move by hand so I don’t imagine it’s the issue, but worth looking at.

I will try and get pics today

 

The fault on the NZ car was the routing of the cable at the final TB tower end where the cable fell off the track so to say ,, not getting his 90 - 100 % open or wide open throttle . Once he got his cable " on track " got his wide open throttle and associated engine full response

I can certainly be wrong on the details

A note of understanding is at the idle screw stop the value of % open will never read 0 % but more like 13 % from reading others and mine , this may have to do with an absolute closed reference as air drum tight but not the case of the idle screw holding plate off ( never adjust this idle screw , I never saw my idle screw on the inside of TB ) throat and the IAC valve never stepping down to be fully closed

 

Gotcha. Mine is def on the track as I took the supercharger elbow off to get a good look in there.

Yup I see 12.9 on idle, have no plans to remove TB or touch the TPS or idle screw, control valve etc. my idle seems to be one of the few and far between that is actually perfect. Go figure!

 

There are markings on the final or next to final throttle bellcrank labeled as MT and AT denoting the transmission type , manual or automatic

 

Just a few pics



TCA with no throttle

Full available throttle, pulleys moving in unison

Extra travel from removing lockdown, but now not moving in unison from point of extra travel