hi folks,

ive found out that my tps reads 0.52 when the throttle is shut, i wanted to adjust it to 0.48-0.50 but i cant go lower than 0.52 V. my WOT also only reads 4.37V.

should I turn the tps sensor to read 4.5V WOT and then adjust it to said 0.48-0.50 shut with the throttle stop?

car is a 88 civic sedan with the D15b2 engine. 90hp

thanks in advance!

 

The closed voltage is more important than the wide open throttle voltage. 0.52 should be close enough. If your idle doesn't settle down quickly/normally or its surging at idle, 0.02 might be too much but I think you will be OK.

 

thanks for the reply, my problem is that even with the throttle stop removed it reads that value, as soon as I barely touch the throttle body with the screw its surging idle. eg. 0.57. there is literally no room for adjustement.

not sure if thats right. from what i am thinking that adjusting the WOT value gives me the necessary range to adjust the shut value.

just for context i made the mistake to play with the stop screw but I am fighting an issue where the throttle is tricky to drive since the innertial force to rev it is too high.

 

The throttle stop is usually set perfect from the factory. I usually don't mess with it. If I have to mess with it, I adjust it till, with the engine running, I can drop the throttle plate closed and it not stick inside the throttle. Once it's as closed as possible without sticking, I disconnect the IACV and adjust the idle bypass screw until the idle is around 750rpm. Then plug the IACV back in and you should be good to go.

Idle value is way way more important than WOT. The ecu most likely considers anything over 4v WOT anyway. At some point it ignores the TPS and looks at the MAP value harder. There is a large correlation between MAP and TPS at idle, but not so much at WOT.

 

There is no access to modify the value in an OEM ecu, even with Hondata, etc. But with any aftermarket standalone ECU this is how it deals with throttle. OEM ecus work the same way though.

 

makes sense

I will try that, i repositioned the sensor now that i have 0.49V when shut but my idle is pretty high at 1500, can it be that the stop screw is out too far? might adjust idle tomorrow as u mentioned with iacv disconnected

also if u adjust the stop screw as u mentioned, u do adjust the tps sensor to read 0.49 or 0.5 afterwards or what is the correct procedure?

thanks a lot in advance!

 

Throttle stop is not equal to idle bypass screw.

Idle bypass screw is flathead screw near top of throttle body.

Set throttle stop screw, then set TPS voltage. Idle bypass screw has no bearing over throttle stop.

 

alright, will do it! thank you a lot!

 

hi again, I did as mentioned above, now the problem is that that sometimes the idle loops rpm go high and low periodically

sometimes idle will just be higher then what I adjusted it too

that just happened after I disconnected iacv and reconnected it after adjusting idle rpm


is there a way to relearn idle? or what else could be wrong?