whats the most likely cause my idle jumping between 150 rpm and 900rpm...??? its really irratic and when i put my foot down from idle its sluggish till bout 2k... when i start the car it runs fine till the start up map stops then it jumps up and down... runs normally but won't idle... it's only done it since i did a plenum pull. i have also found a vacuum hose at the rear of the engine on the drivers side that was not connected. i can't find anywhere it could go as it is only short and i dont know where it goes coz i cant trace it coz its down to low, i'm not sure if its the reminance of the thing in the passenger wheel well (can't remember what it called!) as i cant see it where its suppossed to be so im assuming its been taken out.
ok i have a consult for my lappy so i monitored everything this afternoon. tps is 0.4v at idle and works fine, i cant find any more vac leaks but i think i can hear it, i dont wanna tighten the plenum bolts any tighter coz i dont wanna strip the head but i'm sure its not coming from that... i noticed on the consult the two o2 sensors arent getting the same reading but their only a couple of months old. how do i test the aac and iacv? neither of the fuel regs leak out the vac lines and what and where is the dampner and how do i test it?
Well the TPS should be 0.44V to 0.46V. Maybe fix that up and ensure that the closed throttle switch is working.
yeah the closed throttle switch works fine, i'll check it again, i know i was 0.4 something lol i'll double check that and check the aac
temp sensor plug is fine, i took it off just for s&g but it only TRIED to idle higher. then still stalled... i did notice yesterday that the consult was saying when i was driving that the closed throttle switch wasnt activated when i was off the throttle... however i noticed later in my driveway when i was showing a friend that it was activating... wtf? i tested the aac and the continuity came up fine (approx 11 ohms) but the FICD didnt give a reading of continuity... but it works...??? and that would only affect the idle if the ac is on wouldnt it? i also noticed that the two o2 sensors arent giving the same reading, one seems more responsive the other you'd almost say is sticky if that makes sense... do the injector wires have to be around a certain way? if their not the correct polarity will thay not fire correctly or at all?
doesen't matter which way for the injectors. U may have a lazy O2 , but i doubt that whats causing ur troubles. Does the car smell really rich when the idle is hunting? Trev
yeah it does... what could that mean? the injectors are intermittently really loud then u cant hear them... PTU playing up maybe?
i noticed something else today, yesterday the egr and iacv solenoids were active (coming on and off) today the car wasnt running as good and i noticed that both the solenoids werent active... wat would be causing this? and how both at the same time?
FPR Check to make sure you didnt squash you fuel pressure regulator at all when putting the plenum back on. I did this once and it would not idle at all. Would sit at 900rpm for about 5 seconds then die. It doesnt take much to wreck the FPR when lifting on the plenum. Both my IACV and FICD valves are inactive. I have tested everything but no answer. They both stopped at the same time which leads me to believe something may have burned out in my ECU. Havnt been able to find another ECU up here to test my theory though. Hope this helps! Cheers Jason
i hope mot. i removed both fpr's before i took the plenum off. when they were active they were going on and off at different times but neither were on yesterday. at all. the car runs like shit when they dont activate but i dont think they have anything to do with the idle...
?? Not sure I understand the last sentence. Are you saying dont think the IACV and FICD not working have anything to do with the poor idle?
yeah coz they have done that since i bought the car but the idle has only been shot since i did the plenum pull
what value for AAC do u get when the engine is warm and its idling? if its >30 then you need to adjust idle screw (so it goes down around low 20s)
so i need to adjust it b/w 20-25%? i have tried adjusting it from one end to the other while its running and it didnt make a difference!
the reason it doesnt make a difference is because the AAC will compensate for an incorrectly set base idle by opening/closing the AAC to let sufficient air into engine to idle at ur idle speed. the problem is if u have idle set very low, say AAC must be open 50%, then you only have 50% of room for the AAC to 'help' out the idle in other cases, eg catching it from stalling etc. recently i had a problem when the car was started when warm, it would always stall (unless throttle used to catch it). this was due to warm idle AAC being around 55-60 (compensating too much for a low idle) and it only had 40% of movement to catch a stall from a start, which wasnt enough. i lowered the idle screw (idle itself remained same due to the compensation) so the AAC was 20-21 while warm idle, and then turned car off and started again, and bingo it worked as AAC had a lot more room to work with so just adjust the screw whilst watching the AAC value (when car is warm) and get it to low 20s
but it sounds as though its not idling but that aac is tring to catch it! i'll definately do this first thing in the morning... but why would the car drop low enough for the alternator light to come on then jump up to 1100rpm for one cycle then back down then back up... goes down for two then up for one etc
no idea for that, im not saying its your problem, but given its one of the main things to do with idle, you want to set it right and rule it out first (just like you want to rule out temp sensor, that the timing is set right, fault codes in general, vacuum leaks, etc)
