horrible shuddering idle

Car starts fine

Drives well

Shifts ok

No cel

 

However, at idle the car acts like its going to stall (occasionally does)

Just started yesterday. Going to upload a video of the shuddering idle to youtube. Will post link/try to embed here afterwards.

 

Seems like vacuum related, not sure.

Any ideas?

 

Thanks

Intake gaskets are most likely the problem.

 

Pcv and maf cleaning fixed this for me though.

Could be a bad coil. It won't set a CEL or a blinking CEL at idle.

Hmm ok

Thanks. Sounds like a place to start sniffing around

My car is doing the same thing. RPM's at idle just drop sometimes. It stopped for awhile & I spaced it, but it just started again. Seems to be some what common but a lot of different possibilities. Keep us updated

Got worse tonight!

Going to pick up O2 sensors and plugs tomorrow.

Driving the car makes me nervous. It dies during deceleration (in gear or neutral)

Dies at idle

**** this thing man... ughh

Did you clean the MAF sensor with the $8.00 can of MAF sensor cleaner first.

 

Then did you spray Carb Cleaner around the intake manifold to TGV's to see if the thin OEM o-rings are leaking ? that is the normal fix for these cars, when you see the new o-rings next to the old ones you'll understand. The o-rings are $20.00

 

 

 

There are a ton of threads about this issue.

 

Oh Yea, If you buy a front O2 make sure it's a OEM one, that's seems to be what recommended here.

or remove and clean the OCVs with a can of $9.00 brake clean and about half hours time, for both

some seafoam couldnt hurt

some seafoam couldnt hurt

 

Have you had any luck with this stuff?

^ I think a lot of us that have been around for awhile use it. It does what it says it does when done properly. pretty much a steam cleaning of all your upper engine parts and piston domes

Have you had any luck with this stuff?

 

I always use seafoam every oil change. But I've only used it through the gas tank. That method hasn't' fixed this problem for me. I attribute seafoam for helping keep my 93 Impreza running as long and well as it does though.

Did you clean the MAF sensor with the $8.00 can of MAF sensor cleaner first.

 

Then did you spray Carb Cleaner around the intake manifold to TGV's to see if the thin OEM o-rings are leaking ? that is the normal fix for these cars, when you see the new o-rings next to the old ones you'll understand. The o-rings are $20.00

 

 

 

There are a ton of threads about this issue.

 

Oh Yea, If you buy a front O2 make sure it's a OEM one, that's seems to be what recommended here.

 

Excuse the noob question... the hell is a tgv?

According with the service manual this are the possible causes:

in order :

 

- Electronic throttle control

-manifold absolute pressure sensor

-mass air flow and intake air temperature sensor

-Engine coolant temperature sensor ( only in low temperatures)

-Ignition parts (Ignition coil and spark plugs)

-Air intake system (air leaks in the intake system)

-Fuel injection parts (check fuel injectors, fuel pressure regulator and fuel filter)

-Crank shaft position sensor (ensure secure installation)

-Camshaft position sensor ( ensure secure installation)

- Oxygen sensor

- Fuel pump and fuel pump relay

Thank you everybody with help and advice!

 

Will keep you posted once fixed and what fixed it

Excuse the noob question... the hell is a tgv?

 

Tumbler Generator Valves, they sit between cylinder head and intake manifold, help with emmisions and cold starts

I had the same exact problem

I removed the white plastic pice with the foam around just put a hose between the manifold and the map sensor which is where that is located on the same bracket as the boost controller

I was under the impression that that pice was a "check valve" it isn't its a inline filter to keep oil and debris from entering the map sensor as its after pcv system, as soon as my local subaru dealer figures out what it is ill order a new one but I broke mine apart to find out exactly what it was so that's why I just put a straight tube in place of it. After inspecting the pice I found two sandwiched pieces of filter element that were dirty with oil which was not allowing the map sensor to get a accurate reading under vacuum which causes the hesitation and stalling when not on the throttle.

That's interesting

 

I would go with cleaning the ocv's as a common issue though in this case.

Intake manifold gaskets solved the problems.

Replaced plugs and wires too while I was in there

 

Thanks again everybody