Hey everyone,

as most know, I have been having issues with my car fluttering and loosing power. Well I got a guy to do a datalog and send it to Vince and he said my fuel trims are really bad.

What could cause this?

My mods are: gm stage1, synapse intercooler, CIA 3"catted dp, 3" CIA catback with res delete, dejon hotside pipes, and the airboxmod with stock elbow and k&n drop in.

Any help is appreciated

 

Check your MAF sensor, i see you have a k&n filter, if there is to much oil on the filter it can gety sucked up through the intake tube and stick to the maf sensor causing squirrly fuel trims. Take it out and spray it with maf cleaner or you can use brake cleaner but i woodnt reccomend it.

 

Any quality electronic component cleaner will do for the cleaning of the MAF. I suspect a boost leak somewhere myself. Most common fuel trim issue that can't be tuned out.

Many like Term2 & Blueberry have had several instances of a cracked Synapse IC end bell.

 

The mad sensor looks clean, I had it out yesturday, and I had my stock intercooler for a bit and it did the same thing. Would fouled plug cause this, I'm gonna look at them tonight. I did a boost leak test from the start of the hotside pipes to where the cold pipe connects to the throttle body, and there was 2 pin holes in the synapse ic but I fixed them an re pressure tested it and it was good. Is it worth getting it tuned to see if it will make any difference?

I really need to get this figured out.

Any other suggestions?

So would unhooking the maf maybe pinpoint if it's the maf.

 

How bad are the fuel trims? The K&N drop in shifts them 6-7% with the airbox mod. A tune will help that if they are repeatable. I think there is another issue somewhere though. How many miles on the plugs?

 

17k kilometers(since the car was new)....

Different peopl who drive behind my car say there big puffs of black smoke lol.

 

Slight boost leak?

 

Hmmm....I did a boost leak test from the upper charge pipes to the throttle body.... Maybe I should inClude the entire turbo system?

 

put as much as u can back to stock and take it to the dealer and make them fix it

 

They'll say it's fine after beating the **** out of it if no CEL is on. Misfire on stock tune is usually the plugs. If you drive it hard, you may be due. A lot of guys change 'em every 10k miles. I go like 15k miles myself.

No BOV mods on it right?

 

How bad are the fuel trims.... it takes +or- 20 to set a cel IIRC.

 

Nope, no bov mods. I have had it 2 4 different dealers and they couldn't find anything... I dunno what to do.... I know it's pissing me off

 

Change the plugs, get a good tune for the intake. Tell Vince to tune it for .88 lambda, no richer if you decide to go with Trifecta. He has opened up more tables than HP Tuners to date. The GMS1's Lambda is still very lean in the high load mid rpm areas, just like the stock tune.

Our DI engines puff some black smoke at shifts normally.

I prefer to tune my own stuff now. I had the original Trifecta but didn't want to ante up with every mod, email logs & tunes every time I change it up. Terminator2 helped me out a lot when I was learning. Still does. If you have someone close there with HP Tuners, He'd work with you as well via email, ect. He's been pretty busy IRL lately though.

 

So should I get it tuned even with this issue, will it hurt anything? That's my biggest worry

Here's some pics of my plugs



Also, is there anyway to tell if my maf is fried??? Do I just unplug the connection and if it rumba the same, it's fine and if it works better it bad???

 

They don't look that bad yet but it's pretty hard to tell. Gap them to .030 and see if that helps. Plugs are pretty cheap, worth a try replacing them anyway.

I wish I could log your car to see what's up. Any flashing (misfire) CEL's when it breaks up?

I doubt your MAF sensor is shot.

 

Nope no cels, nothing. Not even any codes.... I'm assuming it's a vacuum leak because I'm still boosting the same as I have been since the stage 1 kit. Lately I have noticed when I first start my car I noticed that the gauge shows 25-30(Canadian gauge in kpa)in vacuum and it used to be at 20, when it warms up the vacuum will drop to 70-80 and it used to be at 60. Is this normal or would this show that I have a vacuum leak. The reason I think this is because more vacuum is more restriction. When I get my fueltrims from the guy who datalogged me, I'll share them with ya.

 

There have been issues with the o-rings on the S1 sensors leaking. I had larger ones with mine from Performance Autowerks. Make sure the lower CP sensor is flush. They are supposed to trim the sensor boss a bit to get it to fit right. You may have a small leak there but it should have shown up in your leak test.

 

what are your short and long term?

 

Are you encountering this problem all of the time? Because I have the mods in my sig, and lately I have been having fluttering issues, but it is very intermittent. When it happens I can only boost 6psi max, and it flutters very badly each shift. I can't find any reason for it to occur, I've done most of the things you have as well to check it. I can start the car, and go drive and once a week or so it does this, and I can just go run into a store for 5 mins come back restart the car and its fine, boosting full and blowing off perfectly fine. The other day it did it after sitting for about 30 mins, and I tried turning the car off and on a couple of times and nothing changed, then a few mins later I was sitting at a long light, and when I left 2 or 3 mins later (without resetting the car) it was perfectly fine again. It makes it very hard to trouble shoot...if you get any answers please let me know.

 

If you have more vac than your supposed to at idle, it sounds like something is plugged up that isn't supposed to be. PCV valve, or something like that?

 

my car at ilde sits at 23-24in/hg's so that should be about normal....

I threw my cars 2nd ever CEL tonight... don't know what it is yet but will when I wake up!

 

Yeah, this issue is 99.9% of the time. Also I had the pcv valve replaced.

 

I've had the 'balt break up at high rpm's & high loads during a 3rd gear pull a few times and it closes back the throttle. I guess I don't understand what the OP means by flutter. Is it stumbling and pulling boost? Must not be a severe misfire or the CEL would flash. Of course the fuel trims were whacked when it happened due to the bad input from the MAF sensor.

When mine broke up, I was logging and the MAF frequency (that normally runs around 10k Hz) at WOT was jumping around to 15-18k. After it did this a few times it backed off the throttle on me.

I had just moved the MAF to the lower CP so I figured it was engine vibration. Only happened two days then after reloading the tune, never happened again.

I guess it could be the MAF but without logging it for you it's just a guessing game.

 

So should I unplug the maf to see if it helps

 

newb question here, whats the best way to test for a boost leak. i think my buddys car has one