idle surge bad ecu???

[razrman8]

99 gsx.. injen intake only mod..

when i first brought my car home a couple months ago i would go to accelerate and push the pedal and it would sputter a little and felt like it just didnt want to move... did some diagnosin.. fixed a boost leak.. and swapped out the tb... im pretty sure it was the tps just being bad..

about a week ago.. i started experiencing IDLE SURGE... my car would idle at about 2200 when first started.. drop down to 12--1400 jump up to about 2000 drop.. constantly. push in clutch roll to stop sign surge surge surge.. threw a p0505 code (idle control system malfunction)
read up on it.. and..

- took out and clean isc.. no fix
-swapped out with the black isc and still didnt fix it
- performed boost leak test...stock intercooler piping had a hairline crack in it fixed that also cleaned the intercooler while doing so
- put new valve cover gasket in( old was would let air seep slightly)
- cleaned the tb real good

after all this i start it up.. it still does the same thing idles high and surges... but now it feels like it did when i brought it home push on the gas stalls kicks in a little... i hooked it up to the obd2 scanner and it reads OPERATING ERROR..
now.. does this mean that my ecu is bad?? because before when i would read codes itd read them just fine and now it reads operating error... of not i have no idea what else can be the problem i just dont know what else i can do or that it could be.. whole situation is just stressing me out

 

[mrbill86]

I had the same problem on my 90 laser. Turned out to be the base idle set screw on the throttle body. There's a little rubber o-ring on it and when it goes bad, that screw will adjust itself up and down and cause idle surge. Try replacing that. If not, then check your other idle control sensors.

 

[gusu]

If you think it is your ECU then have you already checked for leaking caps?

 

[TTstealth94]

Doubtful its the ECU. replace you BISS o-ring, and set the idle correctly, check v-faq if you don't know how. You cant just turn the BISS and expect it to be set correctly. Has you actually tested the the ISC's with a meter?

 

[razrman8]

I had the same problem on my 90 laser. Turned out to be the base idle set screw on the throttle body. There's a little rubber o-ring on it and when it goes bad, that screw will adjust itself up and down and cause idle surge. Try replacing that. If not, then check your other idle control sensors.

ive qustioned that myself.. but i didnt want to mess up the biss adjustment.. i have a whole other throttle body just chillin in ther garage. i might just tryswapping them oer after i swtich the blacktop isc onto it.. to see if that solves it. i dont wanna mess up the biss

If you think it is your ECU then have you already checked for leaking caps?

no.. not yet.. i havent.. i was under the car all day yesterday and jut ahd to step away for the night at 8.. and on top of that .. had to take the plastic uicp part off and the ic out... and those are a b*** to get out.. well at least the first time around

Doubtful its the ECU. replace you BISS o-ring, and set the idle correctly, check v-faq if you don't know how. You cant just turn the BISS and expect it to be set correctly. Has you actually tested the the ISC's with a meter?

no i didnt.. but it moves when the car is ignition on so im pretty sure its workin

 

[razrman8]

UPDATE
you will never guess what i was.. all this stressing ive been doing.. throttle body swaps... isc swaps... considering ecu...
AND THE DARN THING WAS JUST OUT OF GAS!!!
i feel so embarrassed to say it...my float is sticking at 1/4 tank so i thought it had gas in it... it didnt at all... but i think idle surge was fixed with tb swap .. also think obd2 that i had before i requested another one was faulty

 

[tsi209]

Lol glad u found out the problem