2fast4u98

I bought a 99 Trans Am today with an ATI Procharger kit on it for $7400. As long as I never ever punch it, it seems fine. But as soon as I give it any kind of acceleration it completely bogs out and almost dies. Its throwing the SEL and I had it checked at the dealership...says its a MAF and a few other sensors that go along with it. I replaced the MAF with one off of Z28...same year and working car and its still bogging.

Does anyone know if you need to make additional mods to the MAF when supercharging the LS?

I have good fuel pressure, spark etc. not sure whats going on any input or suggestions would be helpful.

Thanks

2fast4u98

Also wanted to note that car is constantly surging, right when it starts up and the whole time that the car is being driven it goes up and down never staying at a constant idle. Its going from 800rpm to 1500rpm the whole time.

ablakez28

iTrader: (9)

Sounds like minimally you need a good tuner to once over the tune and possibly the vehicle itself.

Ericmck2000

Surging. Hrm. A log file would always be helpful....

tording99Z28

iTrader: (3)

Sounds like a tuning issue. You will want to get a tuner on it quick before you end up destroying something, it could be bogging because its going lean on you and you will melt a piston pretty quick detonating under boost.

Bob@BruteSpeed

iTrader: (16)

I agree, you never know if it wasn't reflashed back to a stock tune before you bought it. Do not get deep into the throttle until you get it checked out! Bob

2fast4u98

Thats what a friend told me..."stay out of it and take it somewhere to be tuned" I was just hoping that I would at least be able to drive it with out getting into it for a little while, but the constant surging makes the car a pita to drive. Keep it coming guys.

Does anyone know if a stock MAF is ok to run on the car, or does it need to be upgraded?

Bob@BruteSpeed

iTrader: (16)

Stock maf is just fine to use. Bob

123quattro

Get it tuned before you blow it up.

The Alchemist

iTrader: (19)

My advice if you want to drive it to get it tuned is to disconnect the blower belt so you don't have any boost. Like everyone said, it sounds like the tune is way off.

Bob@BruteSpeed

iTrader: (16)

The bypass valve never lets the engine see boost until it goes to zero vacuum, which is close to wide open throttle. As long as he drives it like he is being followed by a cop he'll do just fine. Back at the old shop we use to have people drive their untuned ProCharger cars from many states away without any problems. They'd get it to us, then we'd swap out the stock injectors, reflash the computer and back it onto the dyno. Bob

ramairetransam

iTrader: (18)

you could always get a tune by frost tune for the time being .

The Alchemist

iTrader: (19)

Hmmm, didn't know that. Just for kicks, is there a way to change that? Say I want to see some boost at part throttle settings?

The Alchemist

iTrader: (19)

That's assuming he has a programmer at his disposable. I'm guessing that if he's going to the dealership to get his codes checked, he doesn't have a programmer.

2fast4u98

You guys are right, no programmer and just bought the car yesterday. Took a closer look/ listen to the engine. I found that the PCV line was cracked open in 2 places making a vacuum leak, it fixed my idle problem but I am still not able to throttle the car without it bogging.

I also noticed that the vacuum line that runs from the throttle body down to the valve cover has been capped off in both places. I have a 98 Z28 thats an ongoing project so im going to try swapping everything from that car to the 99 Trans Am and see what happens.

massls1guy

iTrader: (9)

You have to be careful with the PCV system when using FI. You don't want boost going into the crankcase.

Bob@BruteSpeed

iTrader: (16)

http://www.ls1.com/ed/procharger_owners_manual.pdf

Here is an older copy of the ProCharger f body installation manual. It shows what is done with the pcv system. Bob

2fast4u98

Bob, thanks for the PDF of the procharger install, now I can go through everything and make sure it was done right.

Still having some issues, I replaced all of the cracked tubing for the EGR, but the car wants to bog when floored. MAF code has gone away but its throwing a code that says its running too rich. I thought with a supercharger I'm suppose to be running a little rich?

I'm in bloomington, il...if anyone knows of someplace that actually knows hows to tune cars, please let me know so I can have this thing looked at before it explodes on me.

The Alchemist

iTrader: (19)

You're bogging because you're not tuned, or the tune is way off. STOP GOING WOT or else that motor is going to get toasted before you go through a tank of gas. There isn't anything mechanical you can fix until the tune is looked at. This isn't like a normal bolt-on upgrade or cam that you can drive around fine till you get it tuned. Your normal tendency is going to be to give it gas and drive the car hard, but you have to resist the urge till you can get someone to hook up a scanner and a wideband and see what the car is doing. This isn't to say that there isn't some other mechanical issue that's wrong, but if the tune is off, and you continue to flog it, you're going to be looking for a new shortblock soon.

2fast4u98

I have been staying out of it, again I've only had it 2 days, and I took out a loan on the whole thing..."I'm driving it like a cop is behind me". But even when I drive it like my grandma it will still slightly shutter/ miss for a second and throw a code that says its running too rich.

I heard we have some place called Redline tuning here in town. I'm going to have them take a look at and tell me what they think. Thanks again for the response.