so this is the situation...

i have a jdm b16a2 and was running a p28 chipped ECU but i was experiencing some bad gas milage issues.

someone suggested that i try running a p30 so i picked up a usdm one and when i switched it in i was experiencing some bad idling issues.

when cold it starts to idle at ~2k then drops until...

the car gets warm it stays at about 800rpms but when i step on the gas just a little bit it starts to idle between ~900 and 1200 up and down without stopping. thought it was the iacv or the fitv so took them off and cleaned out both. took off the tb and cleaned that while i was at it (used tb/intake cleaner)

also changed out the TB gasket and put a thin layer of hi-temp silicone on both sides just to make sure no leaks

flushed out the coolant and bled by: filling up the radiator and loosened the bleed valve until a steady stream came out then tightened; while car is off. filled up radiator (through the radiator cap) while car is on and waited for bubbles to stop coming out then closed it

also reset the ecu by pulling the fuse

checked for vacuum leaks with carb/intake cleaner on the vacuum hoses and all around the IM... i do not notice any change in idling when spaying the cleaner...

i dont have any cels

still bad idling....

switch back the p28 ecu and it still jumps

what do you guys think? bad ecu? or something else...



Modified by blk2mid2sol at 4:15 PM 6/17/2007

 

anyone?

 

this happened with my pr4 ecu that i was running with my LS i switched back to the p06 and it went away, it sucks now cause i have a 500 rpm difference in redline but im getting better mileage so i guess i have to deal with it...

 

haha in this case though i want to have the p30 running in my car because i want better milage...

thanks for the response though.


another thing...

when i was bleeding my coolant after i cleaned out my fitv and iacv i did not have any coolant on hand, so i used just water.

do you think that could be the problem?

 

okay flushed my coolant today. bleed it out by filling up the radiator and opening the beeld valve until a steady stream came out then with the radiator open i turned on the motor and kept on adding more fluid as bubbles came out and level went down...

while i was doing this i noticed that my fitv was leaking fluid....

do you think that i need a new one?

 

any responses would be greatly appreciated thanks

 

bump.. driving around with everyone thinking that i want to race them... it frekin sucks!... doesnt help that my car is primered either

 

another thing... when it is warming up the idle does not go up and down, only when i press on the gas pedal then it starts and then after a while stops... but if i drive it it starts up again and does not stop at all during idle...

 

any one have any ideas?

 

HUMMMMMMMMM?

 

vrrrrmmm.... vrrrmmm... vrrrrmmmm...

 

I had silmiliar problem, several times. Its VERY frustrating.

 

thanks ill give that a shot... i have read that you could use carb cleaner to also check for vacuum leaks right?

 

tried to check for a vacuum leak today with some carb/intake cleaner spayed down the vacuum hoses and all around the IM, still did not see any change in idling...

also changed out the fitv to a used one that was working well on my old motor... no difference

another thing... when i changed the ecu back to the p28... the jumpy idling still lingers...

any other suggestions?



Modified by blk2mid2sol at 4:16 PM 6/17/2007

 

Even though the idle sucked with the P30, did you get better gas mileage?

 

haven't figured that out yet b/c i left my car running for quite some time trying to find the vacuum leak... and i have been switch my ecus back and forth quite a bit the past couple of days....

 

But it idles fine with the P28?

 

not anymore for some reason...

 

found the problem, my throttle plate was not closing all the way... guess when i cleaned out my TB i cleaned the little bit of carbon deposits that was helping the TB close all the way.