of course aj16.
not sure exactly how the cable should feel, it feels taught normally. If i manually move the mechanisim to wo then the cable feels limp.
but at idle it feels taught.

 

I had a vacuum hose off under the intake manifold going to the EVAP valve

There is a short-hidden hose from the FPR to the manifold

 

I'd test by having a helper push the throttle to the floor. Then try and turn the throttle lever on the engine by hand and see if it moves to the stop.There is a threaded adjuster on the end of the throttle cable, it may simply be out of adjustment.

The purpose of the jumper on the fans was to keep the fans running on low all the time because there were occasions where the fans could go from off to high speed, bypassing low, and the inrush of current would blow the fuses. By having the fans on low, the step to high speed used much less current and didn't blow the fuses.

I'd want to test the manifold vacuum with a mechanical gauge before deciding there is a problem. I don't think the various phone based apps are reliable with all parameters on the Jaguar ECU.

 

The programs I use seem to be consistent enough. The MAF readings are off by decimal points, but everything else seems to be read normally.

Don't quote me on the throttle % at idle, it could be different for the x300. The XJS cars have them at 12.9%.

65% at WOT can't possibly be right though. Could be a failing TPS if there isn't slack in the cable at idle. That 65% has got to be an indicator of the problem. That TPS isn't inexpensive, and there are no known alternatives.

Has the butterfly been cleaned? The cable might be pulling, but maybe the gunk that collects there is creating a problem.

 

it has been cleaned. On the weekend i will check that it is opening and closing properly with push on the pedal.
if it is then i know it is the tps.
if it is not then i will fix that.

the vacuum reading at -8 is also a concern

 

GEMS can kind of learn base idle it just can’t account for big changes which is what the “new” pot setup app is for.

when you are too far away it will not even try to move the stepper to help it idle. if the iac stepper is broken you can get some very weird drivability problems as well

mine was like 10 idle to 90 wot

 

regular driving all seems to be smooth and responsive.

 

this video is on a bland rover but it’s the same deal.

the elm eobd pid will probably lead you down the wrong path without knowing the closed throttle voltage pid which you can get with the real tools.

i think it’s usually in the ballpark of .6v which translates to 12% on a 5V scale. easy to check the output with a meter or scope

 

No chance to really look at anything yet, but i did notice two things.
When the car was hot and my idle was around 1100 in park, when I disconnected the temp sensor the revs jumped right up to 1600.
so it appears that maybe it is running correctly in that regard.

and I don’t know how much i can rely on the vacuum reading i am getting as on many different restarts of the app i was getting different results. -8, -14, -22 even -77
not sure what is the go there.

 

Ok, so in the quick 5mins i had i did just test one more thing.
Still not sure why idle is high as it appears to be closing the throttle all the way, but,
WOT is certainly not opening the throttle all the way.
so where is the adjustment for this again?
when inpush the accelerator pedal tho there is no play the throttle does start to move instantly


Throttle closed. I could not feel any play. So it feels like it is going all the way back. Maybe it is not. Will need to take off the throttle body and clean to determine.

Accelerator pedal flat to the floor. Throttle body is not open anywhere near full. So i assume cable is too loose

 

Would i be right in reading there is an adjustment at the pedal stop/kick down switch?
the reason i am thinking that it needs adjustment here is that there does not appear to be much slack in the throttle cable, and there does not feel to be free play in the pedal.
the pedal is returning all the way up and closing the throttle body, and when pushed down it goes all the way down and activates the kickdown but at this point throttle is only 65% open

 

Someone in New Zealand found something with the final cable Bellcrank and was able to recover but he was comparing the actual mass air flow rate of a full breathing engine

I think he had a cable out of the curved track on the bellcrank which you don't have

Do you have traction control as the cylinder actuator in front of the brake module ? Not all models have this

Some models ( later years , not mine ) have an adjustment between the TC actuator and the TB butterfly tower

 

no traction control.
only engine bay adjustment is prior to the tb

 

the kickdown switch is on a threaded rod, so you have to unplug the connector and rotate it until its correct - the trick is to have the cable at its maximum tension with the switch pressed all the way down, so it will take some fine tuning to get it right and not too tight. (dont want to stretch the cable by having the kickdown too far down it after all)

 

ok,
so i adjusted the kickdown switch, had to wind it in a fair way. i think it is now in as far as it will go, it still turns but i don't think it is winding any more.
throttle visually opens almost all the way with pedal pushed to kickdown, and then when pushed in to activate the kickdown it is open fully.
i will check torque tomorrow when i drive i think it was reading 85% just before engaging kickdown and then engaging to 95% when kickdown is engaged and pedal is flat to floor.
so i will see how it drives tomorrow

what i did notice now is that the accelerator pedal has begun to feel a little stiff now.
the butterfly on the TB is moving easily and freely but the pedal itself is feeling more resistance than before.
what is ideal to be used to lube up the spring and other components on the pedal assembly?

 

In your pic on post # 73 the final bracket you have circled in red has 2 cable sleeve attach points

one marked A and the other marked M for manual transmission

The marking can be hard to see because of age / surface corrosion

Sanding on it may remove the marking so suggest putting oil on it first

The MAF reading in Grams / Second is around 175 for a wide open not superchargered 4.0 , the factory setup supercharged is from reading others around 225

There is a factory chart some people have and my ELM 327 is down as I was playing with one before , I have the chart on a older computer I may not be able to retreive

 

drove nice today.
idle was still high tho, and sometimes when idling there is slight fluctuations, like 780-810 kinda thing, not bad but its there.

but on good news i got my andy bracket today.
Will fit it over the weekend.
just a thought on that note, could a crankshaft position sensor cause a high idle? Or is that more likely to cause misfires.

lets see how it runs after i fit the andy bracket.
new timing might sit the idle better for all i know.

 

The CKPS for ignition timing is in 2 parts

the location of the # 1 TDC as a reference point

The reference point biasing in relationship to the rate of the # 1 coming back around again , RPM ignition timing advancing

There is also a engine load ignition biasing based on the TPS position and expected unloaded engine MAF as an error signal compared to the observed at the moment MAF

Then there is the engine and transmission ECU talking to each other as they dance together , there is a speed sensor inside the transmission

This is a connector clean on the outside of the transmission

 

i understand all the words you have typed but i do not understand them all put together in the fashion in which you have done so.

i miss older cars where there is an idle adjustment screw..............

 

More words in the edit above , thinking a bit for a different way to understand , My training was as an engineer