Funny Idle Problem

[matlock]

HI, I just bought a 1993 240sx and the only problem it has is a bit of a rough idle.....basically it idles at between 500 & 900 rpms it like revs up and hits 900 then drops to 500, is there a reason it is doing this? I am not quite sure what it might be I am somewhat of a newb with engine tuning, I talked to the local nissan mechanic and he said idle adjustment or vaccum leak......I am not sure how to identify and solve this problem, any help would be wonderful.

[s13silady]

does your car stall occasionally when coming to a stop while in neutral??
something simple.. might just wanna check your fuel filter too.. might be old...

[waldorf240]

if it is a vac leak start the car ans let it idel, take some carb and choke cleaner and spray all the vac lines when the car starts to runs smooth. you have found the vac leak (where you are spraying when it smooths out).

[Sanchi]

Ack i have the same problem its horrible, you put it in idle to break and the car stalls!! its madness!! And even when i'm gasing it chokes, like the fuel got cut off or something this happond awhile ago the went away for like a month and this pass weekend it came back with vengence!! Some one told me it might be my spark plugs not working correctly.

My Fuel filter is stock i got 120k on it, might just be the problem. See it does run smooth for me most of the time i though it was the Vac line but its not an everyday occurence mostly when its hot outside, if i keep the AC on it wont stall, if i hit the ac button off it will drop off and die on me, its that bad sometimes. when im breaking i gota gas and break otherwise it will stall. Very dangerus!! ARGGG!!!

[nokeone]

kinda sounds like an ignition problem..i know my car did that to me just before the distributor cap and rotor went out..

[drew935]

I have the same situation happenig with my car now. Did you find out what it was?

[RUTH'LESSDET]

I have the same problem

can somebody post the correct way to do vacuum lines or a sr

[jonnnny23]

yeah i used to have the same problem i did the aiv removal- nothing, then the idle adjustment - nothing, then the carb cleaner- nothing, then i changed the fuel filter and put some of that fuel cleansing stuff you put in the gas, and and then worked just fine.

jon

[trust hks]

Yeah I have the same problem. So basically a worn fuel filter .... hmm...
But sometimes it dies and goes to 0 rpms and comes back!?
Oh yeah i have shitty gas mileage too.

[the240sxer95]

i have shitty gas milage.. SOMETIMES it has a rough idle but it never shut off on me.. MY SUBARU DID..

but thats another case.. anyways


yeah i get bad gas milage and SOMETIMES i have a rough idle (500-900) but NEVER shuts off on me.. BTW i have a 97 240 with 66k on it

[mistaanime]

clean the MAF? or tried using another MAF? cuz Mah car use to juss stall because it falls too low..after i changed the MAF..it works fine...i idle between 900-800 and nothing lower...