T-Rodius

Allright I've had the GM tune in for about 2 weeks now and it looks like I'll be making a 4th trip to the dealer sometime this week. Last time I took it in last Thurs they replaced the Mass air-flow sensor flashed it and sent me on my way. It was running good for probably 2 days then today my boost levels were all over the map. Sometimes I would see tune boost levels 20-22psi, or it would drop back to stock 15-16psi, it even dropped as low as 5-7psi. Right now it sits in the driveway and the last 2 miles before I got home I had no boost at all. Car went limp, I'm tired of this happening just give me back my tune level, it's a lot more fun to drive. I'm going to take as much info with me as I can this time and leave it with the tech who totally pimped me last time I was there. Dude just straight big leagued me, talked to me like I was a freakin moron. Quick re-enactment:

last thursday on the way to dealer and car goes limp.....I think perfect it'll give them a chance to take it for a drive and see what I'm talkin about. Pull up to bay leave it idling run in and grab the tech and tell him it's acting up. So he hops in takes it for a drive comes back and I ask him if he had any boost. With a smug look on his face he nods his head yes..... and I was like does this f***ing guy think I'm makin this **** up, if he would've just stomped on it he would've seen the damn boost drop off like I'm going to drop him next time I get that **** sniffin grin. Anyways I'm just tired of the headaches, this will be the 3rd time I'm taking it back to the dealer after the obviously failed attempt at the kit install. I just want my tune boost levels back, and I want it to be there everytime I hit the pedal, none of this cut-out crap. Is this too much to ask?

Razz2o4

You see alot higher levels than I do. I was lucky to see 14PSI stock, and I dont get 20 PSI w/ the tune untill about 6K at which point I am dong almost 90. Where are you seeing full boost? I am seeing about 14PSI at about 3000 with the tune.

More_Torque_More_HP

Have you done any other mods? Waste gate? What are the codes?

This sounds like another post where he had intermittent boost problems. I can't find the post right now. It might be on another forum. His problem was a throttle body issue. Replacing it fixed the problem.

Little Red Wagon

Although I never got the GM tune my car use to wildly very with boost.If the car engine was shut off it would always be good for a while.So if you shut off the engine before he test drove it it was probably running fine.
Eventually mine melted a piston below the rings and blew oil all over everything.After a new piston and all new rings for the rest it's running fine with boost in the 15-16psi except when it gets real cold.

T-Rodius

During a 70 mile morning commute my boost was at stage levels around 20psi. After about 15mi I couldn't get any more than 7psi. No codes have been thrown. Taking it back to the dealer again. I have not done any other mods besides the GM tune and K&N filter.

esmarkey

Is it possible that the tech didn't cut off the post on the lower sensor and it's in crooked, allowing random air leaks?

Cpt.Carnage

Temperature can also be a major factor, the ECU cuts back the boost on these cars to maintain a constant torque rating.

T-Rodius

does it cut it back or completely restrict it to 0psi?

Cpt.Carnage

uh no, it would only drop it off, probably more so in the autos i have a manual and have seen it cut it back to 10lbs when its -20c out -4f. In the summer i was hitting 18lbs

ivtech

I did not have any problems for 2 weeks. I went to an appointment running fine when I left there I had to give it a lot of throttle to getting going. When I got on the freeway it had no guts and no boost went up to almost 0 and no further. When I was pulling into driveway went to 20 vacuum noral is 16.5.
Next day it was fine when I went out but no boost on the way home. Today got up to 5 psi and it stumbled.
This did start on a day it was raining.
Going to dealer tomorrow.