AMGPilot

Idle miss but fine off of idle, any ideas?

Peter_02AMG

Jakpro1

Sure, it's pretty basic. Fine off idle miss is one thing, but miss off idle fine miss is totally different. Are you missing off idle fine or just occasionally idling and missing but just finely?

Just busting chops. Noone is replying as the question is confusing. Are you skipping at idle but any other time the car feels fine?

chiromikey

omg, my brain just oozed something out of my ear. what is that!!!

Blacksport350

If it is just a light miss at idle that goes away under load, I would guess that a coil pack is starting to go bad OR an issue with a plug as a cracked insulator could easily cause that.

If the car has over 50 or 60K miles, it wouldn't hurt to throw plugs at it anyway.

chiromikey

is the miss consistent or intermittant?

Zod

hmm
what would u say to a car that runs fine, and when pushed performs, but when you come to a stop it shacks and starts to stutter as if it is running out of gas, with idle going up n down.
give it gas again and drives fine

thoughts?

chiromikey

unresolved issues from the larger tb's.

Zod

interesting...how come no one mentioned it before?

Thanks Mike, please let me know if there is a resolution to it thanks

blackbenzz

Vacuum leak

chiromikey

a lot of people were having weird intermittant idle problems with the oversized tb's. i had it with my 78 but fixed it once i properly sealed the y-pipe inlet with the tb and it ran perfectly. there's still problems with the 82mm versions that i don't think anyone has fixed yet.

MB_Forever

You crack me up Jim

To the OP: what rpm range is the car jumping between when it is on idle?

AMGPilot

It's a misfire, not a surge. The moment you come off idle and cross 1K RPM it's gone

Tech-Tune

I am experiencing the same thing.
Anyone know what could be causing this?

Zod

Are you running an airbox yet mikey? Or just reusing the 80mm y pipe
wondering if the guys with airboxes are having this issue...

Roseylv

There has been some debate about this. People believe it is the Throttle position sensor with the blade being open at only 1% compared to a stock TB which is @ 3% at idle. So i presume the car is being starved of air at idle. There is also the unmetered air problem as well.

wow, that was really funny Jakpro.

Tech-Tune

Wonder if anyone with a stock TB is experiencing this issue?

AMGPilot

there is no unmetered air problem

citylightva

I had this at idle in my 63. Shook harder than my truck at idle and every once in a while would miss. I had leaking intake gaskets and my adaptations were right on the edge (started surging at 80mph roll ons). Dunno if it could be something like that.

benz_addict

Same problem on the CLS63.. but this is not the case for the 55.


I have #5 sometimes and #1 sometimes misfire at around idle 500~2000k rpms. Replaced the plugs, and coil packs and wires. Also replaced the O2. Misfire is still there.

I am going to change the injectors, check thoroughly for vacuum leaks and report back.

E55Bullet

I have a stock T/b and have the same thing, its hard to notice, but it's there, car runs perfect under load?!

benz_addict

Check your engine mounts. Mine feels alot slower.

E55Bullet

I know I need new mounts!