Random Stalls

[disillusioned]

Hey everyone...

I drive a '98 GS-T with a 2.5" Apexi cat-back exhaust, and an Apexi turbo intake and filter with chrome housing. It also has a Turbo XS RFL BOV (venting to atmosphere, previous owner's install). I'm throwing a check engine during shifts after a few, if it's been reset. Last I had it looked at they said it was a throttle position sensor issue, but I don't know why that would be the case during a shift... I'd attribute it to something with the BOV, but I don't know much here.

Anyway, the car has been stalling lately, seemingly randomly. I'll be driving along, and it usually happens as I'm coasting--the engine will just die and the instrument panel will light up. I don't have any trouble restarting it, and it only happens every other day or so, but this is starting to get a bit obnoxious.

Also, when it doesn't full-on stall, I'm noticing that the RPMs will bottom out and the oil light will come on for just a split second, before it picks back up again.

Now, I just had to replace the battery, which I did. I also noticed there was nearly no oil. Last oil change was about 5,000 ago, and I'm getting a full 90k maintenance (including plugs and oil change & filter) done on Tuesday. In the meantime, I tossed two quarts in, because it was so low.

This has happened once while turning, but is usually occuring on straightaways, and around 40mph or 20mph. (But I'm not generally just coasting on the highway.)

The only other problem I've noticed is that the engine will occasionally cut will I'm driving, with the gas pedal depressed. This happened to me at 80 or 90 mph in fourth, as if I was applying pressure and removing it quickly, over and over. It didn't stall, but it sorta of stuttered a lot... something I could see being a throttle position sensor problem, especially if I'm getting a CEL for it. I've noticed a similar problem if I'm accelerating to the top of a gear without depressing the pedal much...

For instance, if I have my foot on the gas enough to accelerate, but just barely, and start to hit the top of second gear, I've had the engine cut off at 4,200 rpms. If I run it hard, it will go up to 6,200 or so (when I usually chicken out and shift). (I've never hit the 7,2 fuel cutoff.)

I had an Apexi turbo timer, but that was ripped out... Any way a short from that install could be causing this? Admittedly, it had stalled once or twice before the break-in, but now it's much more frequent and a bit worrisome.

Basically, I'm about to spend $330 on the full maintenance shafting. I'm already having them check the TPS and any other codes from the CEL, along with a check for crankwalk. What else might I ask for? Could the plugs be causing the problem? An ECU problem? An electrical short? The BOV, somehow? Oil issues? (I don't see any leaks under the car, and the pressure seems normal, but the intermittent light/low RPM thing has me wondering.) I'm naturally running all premium fuel and drive the car like you'd expect someone to drive a GS-T... Lately, I've been taking it a bit easier, of course.

Anyway, thanks for your help here. I really appreciate it!

--Chris Cardinal

 

[95blackGsTurbo]

I only had to read the first sentence of your problem to tell you that the reason you are stalling out is because you are venting to atmosphere. Recirculate that thing and it will solve all of your problem's and save you on gas milage too. Doesn't matter is it sounds cool or not it isn't helping your car.

 

[iboostdoyou]

yup, stop venting

 

[disillusioned]

Fair enough with the venting, but let me ask this:

A) Why would the car run fine for four months (with just me, more with the previous owner) without having this problem, with no changes to the BOV or anything else internal? What would make it start stalling all of a sudden? Also, why the oil light & low RPMs?

B) How do I convert it to stop venting? I don't know much about it--if it's something I can just have the Mitsu folks do while they're in there for the 90k maintenance, I'd consider that.

Thanks again for all your help!