MY97/98 Esl throttle position readings?
 

At closed throttle the software shows 8.3% and full throttle 88.6%. Is this right? Car idles fine and runs good now mapped, but is a little snatchy when coming off closed throttle and starting to cruise again, acceleration is fine. When at a steady speed cruising with throttle just open it seems like it is hunting ( on off misfire) a little.

Any ideas? I'm assuming from the esl readings it cant possibly show 0% and 100% throttle or even need to. Could it be that when cruising the throttle position sensor hasn't switched off the idle switch due to being set wrong?

Not sure how you measure the voltage but ive read the TPS voltage needs to be 4.7v at closed throttle and 0.9v at full throttle, are your readings close to this (not using the esl stuff)

Hi

Now im no specalist and i dont use ESL but, i got the same symptoms when i was messing around trying to get some pops and bangs.

In the base timing table i changed the 0 load column to -20 (i cant remember exactly what rev range between) this gave me some pops and bangs but i was then getting the same symptoms as you. Just cruising at low throttle position it would hunt slightly.

I just wonded if you have done a similar thing - i haven't got to the bottom of the other areas that will need a tweek as i just seem to have no time at the moment.

Im not sure its a mapping issue but you never know, so I will check.

Just tested the TPS and the voltages read as follows.

0.47v closed throttle
4.31 WOT

So I think the tps is ok, but what about checking to see if the throttle plate is totally shut on closed throttle? Should it be?

Hi

During idle your throttle position will be slightly open to allow air in if it was fully closed it can starve engine of air!

Some systems have a fully closed throttle when you only have the ignition on before engine is started so check the position with only the ign on.

Not to sure with full throttle some systems i have worked on reach 100% at full throttle and some ive come across don't. Not sure but i can only think this may be down to the amount of intake flow versus the size and duty cycle of injectors -(if your duty cycle of injectors are maxed at 90% throttle then all you would achieve by opening the throttle more is weaken the mixture) Does your car have a stepper motor on the throttle body or does it have an air bleed valve for cold start and idle control???

Have you had someone hold the pedal down and then checked if there is any free movement left on the butterfly??

My ESL idle % is about 6%. Full throttle is around 89%
This is on a v2 though

Cheers Dan!

Jimbo, I would imagine that the throttle plate is closed and the idle speed control valve allows the air through for idle.

Hi,

I know on a ford that the throttle flap is still open slightly (cant remember what the value was) when at idle and uses the icv to fine tune the idle speed and lambda.

Yeah it should be adjusted so that it doesn't "get stuck" in the throttle body when close, it is open ever so slightly.

Throttle cable holding the plate open ever so slightly! Cant belive it was that simple.

Nice easy fix and one in the bank for "next time" someone has this problem and you can claim your legend points haha!

glad its fixed, so what are your closed and open readings now ?

Not even thought to check. Will check next time I'm hooked up.

Rig, will send you an email with finished map and logs in the next couple of days before I fill up with 97 just for fun! I will be monitoring things so don't worry.