Lately in the morning the car seems to have a misfire after driving on the highway for 15 or so minutes. Every time the car is fully up to temp. It will sputter so bad I have to pull over cause theres no power. Once pulled over I restart and can usually be on my way and problem free the rest of my 50 mile trip to work. After work I drive home problem free. It seems to be when the car has sat for an extended time that this happens. Car runs great in boost like normal.

so far Ive replaced

- OEM Cap
- OEM Rotor
- NGK plugs gapped at .22

Setup

- OBD0 B16
- arp headstuds
- gsr cams
- Garrett t3/t04E 60./.63
- Ramhorn
- Tial 38
- Open Downpipe
- ETC

365whp 325Tq on 18psi 93 octane

Car has been fully tuned by a reputable tuner since June 1 2011. Ive logged 8,000 miles since then. Any help would be greatly appreciated

 

I have something similar going on with my car but not as bad. When im crusing on the highway i get a jerking when im trying to maintain speed with light throttle. Giving it a little more throttle makes it go away. Doesnt always do it but on and off like you.

Does your problem get better or worse depening on outside air temperature? The colder it is the better mine seems to run.

So far ive done the same as you and also replaced fuel filter, adjusted the valves, and checked the timing.

Bump for answers.

 

What are both your ARF's when your experiencing this problem ?

 

Im showing between 16 and 17

 

Thats the problem, it running way to lean. Go and see your tuner.

 

i dont have a wideband. Seems to only be partial throttle too