Help diagnosing my 1g, sputter/misfiring..

[gtrej01]

Ok, I would like to have some help in diagnosing my 1g. Please see my mods in my profile. Car is running on E85.

Car ran fine prior to taking it to the track last Wednesday. This was my first time racing it since I bought it last month.

I was told car has ran a best of 11.3 before.

1st run I ran a 13.0 then a 12.7. Boost held strong all the way on both passes. on the third pass It began misfiring/ sputtering under boost ans blowing dark smoke out the back.

I checked out the car and turbo is healthy with no shaft play what so ever. I did a boost leak test at 30psi and only heard a hissing sound coming from the Throttle body. the hissing sound got louder once I opened the throttle a bit by hand. Is that normal or does it need a rebuild?

I put in new Spark plugs to see if that was the issue and still the same.

Any help is appreciated on getting the car back running normal.

Please help!

 

[AllWheelRS]

Hissing at the throttlebody is likely the throttle body shaft seals. There is a writeup on fixing that around here somewhere but I'm too lazy to dig it up, there also may be one on Vfaq. You're also gunna want to replace the seal on your idle speed screw while your at it as thats probably leaking as well. Fix the boost leaks and go from there. A soapy water solution in a spray bottle goes a long way when boost leak testing.

 

[gtrej01]

Will leaking shaft seals cause it to sputter/ misfire? If so can I pick up these seals at the parts store?

 

[AllWheelRS]

Yes they caused mine to miss under boost. And the vfaq writeup shows how to replace the seals with regular o rings. I used o rings and 30 k later theyre not leaking.

 

[gtrej01]

So I rebuilt my throttle body and fixed that leak but still have the same issue with misfire/ sputter.

Anyone else that can chime in and head me in the right direction to get her running right?

 

[GRAVEDIGGER]

What do the plugs look like? Maybe it would be worth putting in a new set if it's been a while. Even if they look okay they still may need replaced. I would start there and see what happens.

 

[gtrej01]

Has a brand new set of plugs in there.

 

[GRAVEDIGGER]

How old are the wires? Again sometimes they can look okay, but not be up to par... Fuel filter? Although with the black smoke it sounds like the ignition is breaking up while the fuel is there. Got a log? Any knock/false knock (bad sensor)?

 

[Spyderman7]

I think your previous owner might of closed the gap on the plugs to keep the spark from blowing out at 33psi .Did you gap the plugs to how he had them?Try closing the gap to .019

This is just a guess

 

[GSTurbo1]

AFR? Once you get those seals replaced make sure you check to see if your close to 10 at WOT/BOOST sounds like your burning too much fuel

 

[gtrej01]

Here is a log just driving it down the road. i let off the gas as soon as it began cutting out.

 

[gtrej01]

AFR? Once you get those seals replaced make sure you check to see if your close to 10 at WOT/BOOST sounds like your burning too much fuel

This is what I am leaning to. the only thing I have messed with is the AEM Boost gauge.

There is a option I am not no familiar with on it that lets me raise and lower the % of something. When I bough my car I was told it was for running a certain % of the boost it was tuned for. Later I was told that was not correct. Is this a feature that raises or lowers the injectors/ fuel?

 

[gtrej01]

I think your previous owner might of closed the gap on the plugs to keep the spark from blowing out at 33psi .Did you gap the plugs to how he had them?Try closing the gap to .019

This is just a guess

I replaced the plugs with the same kind and re gaped them at .22 as they were.

 

[gtrej01]

Ok, so problem is still not fixed.

Any help is appreciated in getting the car back and running normal.

I plan on changing the coil pack and knock sensor next to see if that fixes the issue.

I would like to get it back up and running before this weekend so i can make it to the local Import Invasion.

 

[GSTurbo1]

you most likely have a boost leak... did you fix tb leak

 

[gtrej01]

you most likely have a boost leak... did you fix tb leak

I did fix the boost leak in the TB. I will do another boost leak test tonight and see if I missed any.

 

[gtrej01]

Ok I finally got it fixed.

My 1g for what ever reason still had all the stock vaccum lines. One of the line heading to the evap canister had popped off.

I then eliminated all the unnecessary lines and blocked off the she. Now it runs perfect.

Thanks everyone for you help!