yessewey

iTrader: (2)

ok i have a 99 si with s2 IM and TB and well im throwing CEL for idle system malfunction and also for my o2 sensors not being hooked up but thats an easy fix. well ive figured out that my idling issue has to do with the tps cuz i put my finger over the little hole in the throttle body and it will start idling normal even after the point where the rpms go up and if you press the gas it will only go up to like 1600rpms and then the car seems like its hitting the rev limiter. so my question is how do i go about fixing this, i've read that you can adjust the scew on the TB to adjust the idle but that hasnt helped me so far unless maybe im doing it wrong? anybody have any suggestions or know what to do? its getting annoying to have to turn my car off and on when i come to a stop i already changed out my iacv with a known working one and cleaned it with carb cleaner as well.

yessewey

iTrader: (2)

bump

yessewey

iTrader: (2)

bump any suggestions its happening more often now so i've stopped driving my car until i can get the problem fixed.

Former User

Have you pulled the CEL codes recently?

My first thought is that your timing is off.

yessewey

iTrader: (2)

yeah i pulled the codes this past saturday, i have two for my o2 sensors not being plugged in because i just had my exhaust rebuilt and didnt have the o2 bungs yet but will be plugging those in tomorrow. the third says idle system malfunction. i was reading an older thread about how if u put ur finger over the hole where the tps is on the throttle body and the rpm's go down to adjust your idle screw which was true in my case so i did adjust it but nothing it still does the same thing. i havent checked my timing but i will.

yessewey

iTrader: (2)

and also might be noteworthy, my car is turbo and has a skunk2 intake manifold and throttle body if that might make any difference. i already checked for any vaccuum leaks in the hoses, T's, etc and found none.

cheesebeatR

try to replace the tps, just use regular bolts on the new one

yessewey

iTrader: (2)

what do u mean use regular bolts? and i checked the tps earlier and its putting out .47 at idle and 4.63 at WOT so its almost in line just a little off. tried the iacv off my friends b16 and same problem, changed the TB gasket because when we took off the TB it basically fell apart and still nothing. plugged in the o2 sensors so those codes are gone. i didnt get to check the timing because the timing gun we were gonna use was messing up. one thing i did notice was that i would erase the codes and let the car idle and it would start to overheat, so i turned it off and back on after a short period then the CEL would come back on and it wouldnt overheat anymore so im really at a loss i want to check the timing but other than that i got nothing.

cheesebeatR

the tps has bolts that dont have a regular head on them, when you replace it its easier to just replace the those bolts/screws... on the over heating thing you might have air in the cooling system, burp the system. what code did it throw after you restarted it?

yessewey

iTrader: (2)

i see, should i really replace the tps though since its reading right? i checked for any dead spots as well and there were none. well the code pops up randomly after i start driving for idle system malfunction. also i wanted to add that when i unplugged the ecu to clear the code then plugged it back in when i started it it will idle at about 1k then it will go up to around 1500 and idle there, i've tried to adjust the idle screw on the TB and nothing happens the CEL doesn't come on yet but it still is idling real high.

Former User

Do you have CEL code P0505? If so, check whether unplugging the IACV with the engine idling changes the idle speed. Also check for a vacuum/intake air leak.

yessewey

iTrader: (2)

yeah for idle system malfunction. i've already checked for vaccuum leaks and i dont see any leaks on any of the piping, when i disconnect the iacv the idle drops back to normal , around 1k.

MHDesigns

Mine did the same thing. Mine as well will stop at around 1500prm's and bounce unless I step way further on the gas, then it would shoot way up. I blocked off the IACV port on the TB and it went away, but that's not proper. I'm in for a solution to this since I want mine working again properly too. Have you tried replacing IACV? Bleeding coolant? Check ECT sensors? Checking for vacuum leaks? Do you have a FITV and if you do it is clean and functioning properly? When you unplug IACV does it drive fine or does the idle just drop?

yessewey

iTrader: (2)

ok now i pulled the codes again and its throwing a code for IACV and for catalytic converter

yessewey

iTrader: (2)

yeah i noticed when i block that port that it will idle normal but i agree its not proper and i would rather have my car working right. i've tried like 4 different iacv's, bled the coolant (which i may do again since we changed out so many iacv's in and out yesterday), havent checked the ECT sensor, already checked for vaccuum leaks, i dont have a FITV since i have a skunk2 TB, and when i unplug the iacv the idle goes down to normal, not sure if it drives fine though.

Former User

Adjust the idle speed with the idle screw on the throttle body as detailed in the service manual.

MHDesigns

Also check to see if your throttle cable has too much tension on it.

yessewey

iTrader: (2)

i already tried adjusting the idle speed and it doesnt do anything just continues to idle high. i already checked the throttle cable and it has the proper slack in it as well. right now i dont have a obd2 scanner so i unplugged the ecu to temporarily erase the codes then i was taking off and the car kept dying, then once i got going the car was overheating sitting at about 3/4 with no CEL so i blasted the heater. while i was driving if i barely holding the throttle it would jerk back unless i gave it more throttle. after a little driving it stopped that but when i was almost home i was taking off from a stop light and i shifted to 2nd then my car started slowing down no matter how much gas i gave it so i just turned it off and on really fast and made it home. as of right now the CEL still isnt on.

Former User

Check the mechanical timing and compression test the cylinders.

yessewey

iTrader: (2)

okie doke i'll check that tomorrow and report back with an update

yessewey

iTrader: (2)

alright so i think my friend finally solved the problem. my throttle body spring where it attaches to the cable was getting stuck and not returning all the way back when i would let off the pedal, it wasnt that the throttle cable was too tight though was the weird part. so he took of the throttle body and loosened the little screw on the bottom of it where the spring is and adjusted it and seemingly has fixed my problem so far, i'll have to run the stock ecu to make sure but with my p28 it doesnt have any problems which was my temporary fix when first started doing the surging idle.