Wierd Idle issues

[Frostitute]

Hey everyone

Motor is an SR20DE. I've just been having this problem since Saturday and I can't quiet figure out what it is so just asking if anyone can throw some suggestions in.

Don't know if the heat might have caused this problem but could be a factor so I'll throw it in. Having a black bonnet probably doesn't help would get hotter (I needed a bonnet to pass the pits and cheapest I found was black lol).

Anyway the issue is that sometimes randomly on idle (cold start or when warmed up) the rev's will drop down to about 400rpm and car will shake like its going to stall then rev back up to 1400 sit there for awhile and drop to my set idle which is at 1000rpm. Once it start's it won't stop till I take off and get moving again. This only happens randomly I don't think there is anything that triggers it sometimes on idle does it sometimes doesn't.

Thought it might have been an ignition issue but the spark plugs are 10k km old. The leads have been there since i owned the car 13k kms ago so don't know when they were last replaced but I figure it shouldn't be the leads as if it was ignition probably would happen while I'm driving too and it doesn't.

[Drift_R32]

do these run an Idle Control vavle? if so...could be fukt, had it happen before when the ICV was fukt

[RICEY]

Hey everyone

Motor is an SR20DE. I've just been having this problem since Saturday and I can't quiet figure out what it is so just asking if anyone can throw some suggestions in.

Don't know if the heat might have caused this problem but could be a factor so I'll throw it in. Having a black bonnet probably doesn't help would get hotter (I needed a bonnet to pass the pits and cheapest I found was black lol).

Anyway the issue is that sometimes randomly on idle (cold start or when warmed up) the rev's will drop down to about 400rpm and car will shake like its going to stall then rev back up to 1400 sit there for awhile and drop to my set idle which is at 1000rpm. Once it start's it won't stop till I take off and get moving again. This only happens randomly I don't think there is anything that triggers it sometimes on idle does it sometimes doesn't.

Thought it might have been an ignition issue but the spark plugs are 10k km old. The leads have been there since i owned the car 13k kms ago so don't know when they were last replaced but I figure it shouldn't be the leads as if it was ignition probably would happen while I'm driving too and it doesn't.

If having a black bonnet is bad for the engine then me and everyone else with a black car are in trouble hahaha

Random/intermittent faults are the hardest to diagnose. Generally if its plugs/leads/coilpacks the problem wont go away. Could possibly be sensor related?

[Frostitute]

You know ricey when i said i have a black bonnet...no way did i think that all black cars would be in jeapordy haha. I feel so stupid for saying that now :(

I gave the ICV a spray through with carby cleaner and still had an issue. Only a week later did the issue go away completely. Is that possible?

[RICEY]

May have been a blockage in there that didnt clear straight away but you loosened it and it cleared up eventually?

[Frostitute]

May have been a blockage in there that didnt clear straight away but you loosened it and it cleared up eventually?

That seems pretty likely at this point. Will update this thread if anything new arises.

[lee3671987]

i too hav similar problem with my sr20, but in my case it almost stalls while downshifting.....soo took it to hyperdrive they said its the knock sensors, got it replaced.....its much better now but still idle abit rough. altho it doesnt stall anymore.

could also be the injectors or VCT (blacktop) are stuffed.

[grogers]

my AFM had some faulty wires on it and would cause my car 2 play up on idle.

[blaize]

i had this same problem with my old s13. it used to stall when i down shifted/idle went from around 1000rpm to about 200rpm sort of rotating before correcting itself. i just put up with the issue and it eventually went away.