ROUGH IDLE 240sx (yes searched)

[madmeg323]

My idle is good. when i put in the clutch to stop, idle drops down to just above stall. Searched alot of different possiblities, but with no pitures, it isnt alot of help. If any has the pictures of the problem items please post.

ie Tps..ivac..or ivca or whatever it is..

Need help please, I have checked all my vacuume lines and all seems fine.

I have read to replace my platinum plugs, but would this really affect idle?

PLEASE HELP

[dickie]

the iacv is the canister-like unit on the back of the intake manifold. find your idle adjustment screw (you can see it by looking into the engine back in the area described above), and youve found the iacv unit. get out your 10mm open end wrench and pull it off and clean it w carb cleaner.

check your grounds, theres a thin ribbon type cable connecting the back of the valve cover to the firewall and the obvious black battery ground cable. the resistance between the neg bat terminal and an unpainted sport on hte cars chassis should be <.3 ohms iirc. autozone might have the equip to check this for you if you dont.

check your plugs and wires, you may need a tune-up.

are you missing on a cylinder or is it just rough overall?

[madmeg323]

its only rough when i pull up to a stop light. all other times it runs like a top During warm up it idles fine. after almost stalling at a light I can rev it up and it will idle fine, until the next light then it does it again. I just replaced the plugs a couple of months ago.

Anything I could be missing?

[dickie]

youd know if you were missing. you have a very common problem related most likely to a dirty iacv or bad grounding, possibly a minor vacuum leak somewhere.

[OldmanPurdy]

Your plugs probally are not causing that. Iacv is probally the cause like d!ck said, also the EGR could be gummed up too, although its only supposed to be active during crusing. You can also try removing/cleaning the AIV valve if you have an S13.

[madmeg323]

ok, so now all i need is some pictures to help out. Chiltons manual sucks , just no luck what so ever

[dickie]

fsm could help but i doubt it. thats one of the things i keep meaning to take pics of since i have a manifold sitting in the garage but i keep forgetting. if you can wait till this weekend, remind me then and i will get some for you.

[Thebigjc]

Remember the pics for the iacv please, I am also having the same issue and I need to do this also.

Thankyou in advance.

[dcino]

CHECK with your local dealer ther is a TSB out on this condition that will give you the correct procedure to follow. This may require you to change out the ECU with an upgraded program. If you have access to Alldata you can also pull the information from their system.good luck

[MOscapinski]

My car is doing the exact same thing. I had almost every sensor replaced on it already! If you figure out what it is, let me know. I'll do the same for you too.

[dcino]

NISSAN ALSO HAD A TSB OUT FOR ROUGH IDLE THAT REFERENCES TO MUCH OIL ON THE CRANKCASE BE SURE THIS LEVEL IS OK .....THEN

REMOVE THE VALVE COVER I THINK YOU MAY FIND THAT THE BOLTS THAT HOLD YOUR ROCKER ARMS MAY HAVE STRIPPED OR IF YOU ARE LUCKY ARE JUST LOOSE. BOTH OF THESE ARE EASY TO CHECK AND THE SECOND ONE DUPLICATES YOUR SYMTOMS EXACTLY. YOU WILL KNOW RIGHT AWAY IF THIS IS THE PROBLEM.