Revs dropping REALLY low at startup

I've got an 05 LGT with about 70k miles on it. I've done an uppipe, downpipe, crank pulley, AP Stage 1 at 91 (since I can't find 93 where I live), intake and ACT aftermarket clutch and flywheel. I love the way the car drives and have no complaints after I get it moving but I am having some problems, generally at startup with my engine trying to stall.

 

Best explanation I can give is that when I first start the car, usually, I'll give it the little bit of gas it needs to get moving in reverse and when I push the clutch in to coast until I need to start going forward, the revs drop REALLY low, like down to 200-300 rpm and the engine almost stalls, it's actually stalled a few times.

 

If I take the tune off and run it stock, it's even worse and does it more often. I've cleaned the MAF sensor numerous times and that helps it for maybe 1 or 2 starts. I've had it stall one time when I was coming to a stop at a stoplight even. But just once.

 

So basically I don't know what's wrong. I'm pretty sure it's a fuel/air mix problem but I've got no idea how to do anything with that.

 

Anything you guys can think of would help immensely. Thanks.

man i got the same type of issue with my 05lgt .like the first start up of the day is always fine(unless i touch the gas pedal then it drops)but the starts later in the day or say i go shopping some where and its only been a short time it acts the same way or when im parallel parking it loves to stall out. and ive been driving a stick for over ten years so i know its not my footwork. i personally blame the drive by wire throttle system. that things never responding right to my pedal movement ..and i never cleaned my maf yet bought the car with 32,000 mi. and now im at 57,000mi... im gonna try cleaning the maf but still i feel your pain.

maybe take it to a dyno with someone with alot of subu exp>

The biggest thing I've noticed is it happens when I take the load off my engine, when I push in the clutch.

 

Thanx for validating my problem, let's me know I didn't screw my car up all by myself.

Do you need a stage 2 tune with up and down pipes?

I was having the same issue. Tuner think's it's something to do with the fact that Subaru add fuel for 20 seconds after start up. My thought is, as these cars get older it becomes more of a problem.

 

Last night he loaded his map onto my new AP (version2) and today the problem seems to be better.

 

He was thinking Cobb may have cleaned up the Map a bit. I'm no expert, I tell him the issue and he does the best he can. I'm not into all the computer stuff, but Cobb is always working on making things better.

 

Contact Mike at http://www.tuningalliance.com he may be able to help.

yeah mine also stalls after i disengage the clutch,buut then i just throw it back into gear and try to match the revs as best as i can.

Not sure if this pertains, but are you saying it will stall with the clutch fully pressed down (disengaged)? I was thinking that it was stalling with the clutch up (engaged), but not in gear. If that's the case, then the really cold weather is likely causing your tranny oil to thicken up to the point where it's really slowing down the engine to turn the gear shafts without adding more throttle in to compensate for the dyno-like load. Does this happen when the car is warmed up (and the tranny would be too)?

If it's purely related to the clutch movement I would worry about mechanical issues like throwout bearing and the axial bearings in the engine designed to take up the throwout bearing force. If this is the case it can get expensive.

 

This because the pressing of the clutch in itself shouldn't cause anything to happen with the engine.

 

But on my '04 Legacy (Gen 4) I did suffer from a sudden drop in idle RPM when the engine was cold and I did touch the gas pedal after start. It stalled for me several times. Clearly a software issue there. And pressing the clutch may in theory tweak the throttle pedal a tad causing the same problem.

yeah it just happens like say im coming to a stop,if i dont wanna wind down the gears downshifting and just take it out of gear pedal is up or down still does the same. just wants to stall. it def. has been cold but i just had my tranny fluid changed with redline from fredbeans doylestown when they did a clutch setup. idk me personally i blame the dbw. throttle setup i hate it . it def doesnt react rite to the pedal movement. its like a slow bogged down pc with viruses, i press- nothing,then i press some more,then boom it jumps to like 3500 rpms . just not responding to my pedal rite.

I really, really don't think it's a mechanical (clutch) problem. This is the 3rd clutch I've had on the car and they've all done it. All I was trying to say by saying "when I push in the clutch" was that I was taking the load off the engine. It doesn't normally do it in gear, just when I'm coming to a stop and I push in the clutch. The reason I don't think it has anything to do with the clutch mechanically is because like I said, when I clean the MAF sensor or change the tune, it gets better and worsens respectively.

 

I've been driving a lot the past few days because of job interviews and have been paying more attention. It does it a lot more than I thought before. Like if I'm at a drive through, or waiting at a light and just inching forward. I goose the throttle a little bit to move a few feet and when I come back down on the clutch the engine revs drop really low.

I dont know if the tune is what's causing the problem, but with the mods you have done you should really be running stage two.. Give stage two a shot and see if that helps?

I can always try going to stage 2, but I don't think it's really gonna cure the problem. If I'm running stage 1, and I have simply, more breathability, then stage 1 should run no problem. You don't NEED a new tune just because of things you may have done, the tune simply uses the new airflow/exhaustflow better.

good ground? no corrosion around hte negative terminal?

good ground? no corrosion around hte negative terminal?

 

I just bought a new battery before winter and cleaned the connectors myself. It's been doing this for a while.

Just for the sake of it - do a smoke test to see if there are any leaks around the manifold - like the manifold gaskets because other cars has had this problem - especially in cold weather.

Nope, no leaks. Never has been.

Nope, no leaks. Never has been.

 

bring it back from the dead did you ever solve this problem ? i am experiencing the same issues. rpm dip/stall mostly in reverse

Sometimes these issues are solved with an idle re-learn, it's what I did with mine.

No, never fixed it. I do definitely have an exhaust leak somewhere in the engine bay now but that's new and this problem has been going on forever. I found that cleaning my MAF sensor will help for a little while.

i have a new MAF and its still bad maybe ill pull the battery again

This happens stock in an auto with mine. Just the way the car is.

Don't think that it's just the way the car is, it never started in mine till about 2 years ago.

Give this a whirl. Pull the negative terminal from the battery for 15 seconds reinstall and start car, wait for cooling fans to turn on then hit the a/c and defrost buttons. Wait for cooling fans to turn off before shutting off vehicle.

Are you still on a stage 1 tune with stage 2 mods? Have you tried reverting to stock downpipe and running stock map?

 

Have you swapped out intake orange gaskets?