Dat Hunting Idle...

[kai]

Hey guys, so im reaching out because im really frustrated with my skyline and need a little advice in which direction to go if you have any.. So before the car was stored i would idle normal when cold and then sounded like it had a slight miss or was hesitation when warm, it was drivable for a bit and then started bucking and serging.. Also stalling at lights, after a couple days of this i decided it wasen't worth driving so i began work on it.
I replaced the tps because the other one was giving bad readings even after adjustment.. which made no difference.
Upgraded to new spitfire coilpacks and got a new igniter, as well as cleaned the MAF, inspected the plugs which were fine. ANyhow the car has a really rough time starting up..and once warm just stalls out. Don't really know what else it could be, maybe CAS or IACV? if thats the case then i don't know how to test them out. Anything would be helpful because if i can't fix this soon im going to take insurance off. Thanks!

[h4X6]

Clean your iacv

Sent from my A510 using Tapatalk 2

[hp44incgtr]

yea i would be checking the iacv too..

[yanay]

i had same problems. ( cleaned maf, replaced tps (still didnt fix faulty readings) new plugs new iacv new coolant temp sensor ) ended up going to a friend of mine because i have gone over every little thing trying to find this same problem and now its been at his shop for four weeks now and he still hasn't found the problem either if it gets found and fixed i will get back to you with the issue. If you figure this out please pm me and let me know what it was

[kai]

i'm almost wondering.t if it could be a small vac leak but normal your reveal shoot up in that case..so may e a silicon kit would be good to look into, but yea I don't wanna Easter egg this and but a bunch of parts hoping I get it right..i'm gonna clean my IACV and hopefully that's the problem if not I may have to take to a shop unless people have more suggestions

[yanay]

i generally do 100% of my labour but this just got to the point where i didnt care how much i just wanted it done.. he says he will spend a full day on it monday so maybe it will be solved and i can let you know what fixed it by then!

[Skym]

My car did exactly this not long ago, just stalls out of the blue while idling when it's close to warmed up and TPS, etc were ok. I found the intake hose clamp next to powersteering pump was very loose. Tightned it up and started smoother, idle was steady, smooth, etc. It's always that clamp, whether stock or aftermarket bolt clamp that seems to come loose. Need to put a nut on other side of bolt clamp so it won't come undone due to vibration. Or fit a proper racing intake hose clamp (not cheap).

[kai]

alright I'll check the clamp for sure and see, I'll also give cleaning my IACV a try, does brakeman suffice? and yea I don't have much money cause i'm a poor student so I doubt I could afford the labour...so letting me know asap would be awesome! just don't wanna give up with my baby but at the same time i'm kind of lost so its just a pain.

[kai]

brakleen**
#

[Skym]

I would use CRC MAF cleaner.

It's the intake hose clamp (intercooler side) on the intake pipe that exits intercooler and goes to J pipe (intake pipe that goes over top of engine).

Also check all intake hoseclamps (including from MAF to front of turbo and the intake hose clamp infront of turbo is the hardest to reach, might have to remove top intake pipe before J pipe, J pipe and use a long shank flat head screw driver / long shaft screw driver). I overlooked that intake hose clamp by powersteering pump, as it looked tight, but wasn't.

[kai]

yea sensorkleen is safe with electronics and worked well on the MAF, so I'll try that, lol **** sounds like its gonna be tough to get at

[Skym]

Can use a bendable shaft with socket at end (saves removing intake pipes) and jam between shield / exhaust manifold, turbo.

From memory, at factory that intake hose clamp (the one that came loose) is joined to another intake hose clamp via piece of metal. Both intake hose clamps are just behind radiator, next to carbon canister, powersteering pump.

[Dragon Humper]

You can rule out the IAC valve by bumping up the idle with the throttle blade adjustment and reseting the TPS voltage to target. I had all kinds of issues with mine and that fixed most of it. I notice that my base ign. timing bounces all over the place after the engine warms up. That causes some hunting as well. Not sure why it does that, have a replacement CAS but haven't found the time to monkey with it yet.


Jon.

[kai]

maybe i should replace all vac lines for insurance and check grounds? Its just odd how it has such a rough start, and then idles fine at cold temp, then as soon as it gets warm it begins to fluctuate a bit until it stalls, not sure if it still surges because i can't really drive it out of the garage lol.

[Skym]

Whistle sound just before 0 on boost gauge = intake airleak after turbo. That's how I knew it was that. Also rpm needle bounces up and down more than usual with an intake airleak.

ECU has idle stabilisation tables and can see the ignition timing changing roughly + 5 or - 5 degrees via timing light. If have Nistune software, can see it switching between the different settings on idle stabilisation tables in realtime. At same time o2 sensor voltage goes rich, lean. It can fluctuate more when there's intake airleak and if too much engine stalls.