I noticed this morning driving to work that the car will start stuttering if I hit the gas at highway speeds in 5th. It will start spooling good, but as soon as the boost light starts ramping up on the dash the car starts to stutter like it's either missing or pulling timing or something. This is going 60-65 already over 3K RPM's. HOWEVER, in the other gears at lower speeds I have no such problem. I get full boost and good power. The only thing that changed was I just filled my tank with Shell super and I've been running 76 Super. You think it could be bad gas?? Bad MAF? Thanks everyone.

Dorian

Sounds like the BOV is fluttering. I have seen that happen in 5th gear in other GVR4s as well.

So the spring might be shot in the BOV and I should replace the whole thing? Why would it do it only in 5th and not in the other gears??

Sounds like ignition to me. Spark plugs and wires good? It'll start that kind of stuff in 5th gear due to the load and then the lower gears as time goes on and the problem gets worse.

I just changed the plugs and put in a set of MSD 8.5mm super conductor wires. They were used, but I got them from a member here and they appeared to be in nearly new condition. What is the correct gap for the plugs? I put in some standard NGK plugs and set the gap at .030.

AFR at that point when it's stuttering? That would tell you if it's the Maf.

I would have to get an AFR gauge. Is there another way to see what the AFR is without actually having a gauge hooked up? I did notice that when it was stuttering the boost lights in the dash were all lit and it seemed to start its stutter ass soon as the last light came up. Those lights are hooked up to the MAF correct?

Try gapping your plugs down to .028"

Also, I don't trust MSD wires. Run the car at night in the dark and look at your spark plug wires. You might find they are arcing all over the place.

Well that would definitely suck and be a complete waste of money...I hope I didn't get duped on those wires. They sure seem like a heck of a nice set. I will take a look though. I still am wondering if the OP is correct that the BOV is fluttering since he's seen that problem before...I just want this thing for a DD and don't want to dump a whole bunch of money in it. I'd like to keep it relatively stock and just have it in fine running condition for the next owner when and IF I ever sell it. Who knows though, I might end up with the mod bug and just go stupid with it.. LOL!

I'd gap the plugs down first. You might be blowing out the spark.

Comp surge? I get this on my car with low Rpm and high gear. Basically it is the turbo being more efficient than the engine at that point in time so it shutters and sounds like a helicopter. I get around it by dropping gears into a more efficient rpm.

The only way to get fully around it is to make less boost down low.

Just a suggestion.

Thanks for that man. I don't Think it would be compressor surge...I don't think. Only because when it does it I'm already pushing over 3000 up to 4000 RPM's. These things are geared super low compared to what I'm used to. Even my 2005 Legacy GT wagon 5-spd had longer gears and it was running a factory strengthened WRX tranny. I will for sure re-gap the plugs down to .028 and if it keeps doing it, I'll probably look at getting another BOV. I checked the spark plugs last night and couldn't see any arcing in the dark, so I think they're probably OK, but I'm still going to Ohm them out as well. Thanks for everyone's input! You guys are awesome!