One day i blew my MAF, so i had it replaced. Ever since i replaced it my idle has been horrible.

The car idles around 300-550, sometimes dropping to 200 but the car stays alive. My idle is very unstable, and usually you can stay in 2nd gear in traffic going like 5mph, but now my car bogs around like crazy.

Anyone know why or what i should check?

Before the MAF blew the idle was fine, my car isnt tuned yet, you think that will help with the idle? i put in 1 step colder plugs, the idle was good for like half a day, then returned to its unstableness

 

how's the condition of your old plugs? was there any gap left in the old plug?


Latinmax had similar problem to yours. at first, he thought it was the MAF...but turned out to be something else.

 

My idle kind of stumbles now and then. The dealer blames it on the SC. I need another place to go to!

 

my old plugs werent that bad i think, still have em sitting in the garage.

Do you kno what was the cause of his problem and how he fixed it?

 

he blew his engine and he got it replaced

the cause of his bad idling is the head gasket.


have you checked the gap on your old plugs?

 

Ah crap...

i dunno how to read plugs

 

quick question:
Aren't the NKG platinums pre-gapped? I read that they were and so I put them in.

 

get a plug gap measuring tool from pepboy, looks like a dollar coin. Latinmax had rough idle and one of the spark plug was bent. In your case, if it is the MAF, I am wondering how come it gets better when you put in the new plugs. If the MAF is bad, putting in new plugs will not help.

If you want to read the plug to see if your are running rich or lean, you have to boost the car first and then turn it off right away, like right afte a dyno run. Otherwise, ilding will clean the plugs and you wont know how your car runs.

you have to adjust the gap for boosted cars. stock gap is .044 and for us, we should have it gapped ~0.038

 

Do you have a boost guage? What's your vaccum like at idle?

If you don't install the o-ring with the new MAF, it will leak causing crappy idle and stalling. I've forgotten it before, and it sounds a lot like what you've got going on.

 

I forgot to mention that I've got the one step colder plugs. Is the ~0.038 still applicable?

 

yup...it will work. large gap will cause misfire.

 

my vaccum is like 20-23?

 

If you want to make sure it is or isn't the SC, just remove the piping from the SC going to teh MAF and run it.

If it stops idling funny, then it actually is the SC.

My car jumps between 750-800RPM constantly. never stays in one place. I've always assumed it was the SC.

Oh - and a leak at the MAF won't cause low vacuum (17-22 is spec).
It's before the Throttle Body.