random sputter help

[joe sobo]

i did a full restoration on my car, but the last bug to work out is that SOMETIMES when i go to hit boost, the car will just sputter.if i floor it while it is sputtering, my a/f dosen't start to get pig rich. i do not have a good a/f, but instead have the pen type turbo timer.just cruising out of boost, the car runs at about 14.7, and when i floor it, it richens up to like 10.0:1. so i know these are not that accurate, and im not running extreme boost.(stock boost level on a 14b installed on a 2g). i have ported manifold, 3" turbo back.
i replaced the plugs about 2 weeks ago, with the wires and everything else.
would a bad, or going bad o2 sensor be at fault? but i have no check engine light for it.
once it starts to sputter, and i let off the gas to let it go back into vacuum, then hit the gas again, then it will be fine and boost perfectly with out sputtering.
would be great if someone can point me in the right direction thanks

 

[RoryBarron]

Have you done a boost leak test?

 

[joe sobo]

yes , and checked out perfectly.also, if i had a boost leak, my problem would not be random. the car does not sputter every time i get into boost

 

[habitatguy187]

What's wrong with your a/f ratio? I'm kinda surprised that it's not in the 9s at wot. And to answer your question, "No." Your o2 sensor will have absolutely no effect on your car's behavior once you go wot. To get the basic questions out of the way....

1. What kind of plugs?

2. What are they gapped to?

3. What did you pressurize your system to for the blt?

4. How long did it hold?


You could have an intermittent boost leak at one of the 3 (i think that's all) valves in the system - egr, brake booster check valve in the line from the IM to the booster, and pcv valve.

 

[joe sobo]

What's wrong with your a/f ratio? I'm kinda surprised that it's not in the 9s at wot. And to answer your question, "No." Your o2 sensor will have absolutely no effect on your car's behavior once you go wot. To get the basic questions out of the way....

1. What kind of plugs?

2. What are they gapped to?

3. What did you pressurize your system to for the blt?

4. How long did it hold?


You could have an intermittent boost leak at one of the 3 (i think that's all) valves in the system - egr, brake booster check valve in the line from the IM to the booster, and pcv valve.

plugs are ngk bre7, something like that. gapped at .029. my blt was pressurized to about20 psi, and held for like 20 seconds.
i did away with the im to valve cover pcv valve, and added a second breather. also did a egr block off plate.

 

[habitatguy187]

plugs are ngk bre7, something like that. gapped at .029. my blt was pressurized to about20 psi, and held for like 20 seconds.
i did away with the im to valve cover pcv valve, and added a second breather. also did a egr block off plate.

Does it miss out more when the car's cold and still warming up or all the time?

You really want to hook your pcv valve back up because without it there's nothing to pull the gas fumes out of your crankcase (valve cover) and the gas will break down your oil, causing all kinds of problems you don't want.

 

[GSXeclipsePSI]

I always put a new set of BPR7ES in when I have sputtering issues. Also check cam sensor.

 

[joe sobo]

i don't know if it does it when it is cold, because i always let it get up to running temp before i drive.

 

[wdbagger]

Fixed this problem yet? I'm having a similar problem with mine. My car ONLY does it when it's up to temp and never when it's cold. It really is random for me, so I can't tell what's causing it. The temp is the only constant I've noticed so far.

 

[joe sobo]

well, it just went away, after redoing a tune-up, but the guy that bought the car drove it 1,100 miles home, and told me it did it to him on the trip. i haven't heard anything since