Runs Very bad Please help..!!!

Hi guy's I'm fairly new here so go easy on me. I have a 1997 GTP with 150k I've had the car for about a year. OK the problem is when I accelerate any thing over a very slow pace the car boggs down very bad, and if I keep the gas down I hear like a popping from the engine, in addition the boost shoots way up and all the way . If I accelerate very slow like I said its fine, but as soon as I give it a little more gas instant bogg and it doesnt want to go any where, it helps if I feather the gas a little, but still is very bad. Now after reading some of the threads on here, I know I have a few problems already, pretty sure the cank sensor is bad because the tach cuts off sometimes and I have a little exhaust leak pretty sure where the mainifold pipe connects to the rest of the exhaust like just after the tranny. and also I have been using 87 octane just for like the last month(my dad said it would be fine to use, but after reading on here, he was wrong)! But it did seem to run fine on it? I have been driving with the exhaust and crank sensor problem for a while and its been fine? this just started happining, so when it did I insantly put preminum fuel in, this seemed to help a little but the problem is still bad, also It doesnt seem to be as bad when the engine is cold or its cooler out like in the morning? and the engine seems to be running hotter since this problem has started. I also disconected the maf but didnt really seem to change any thing? so any help I would greatly appreciate it, thanks guys:)

did you try to drive it when you unpluged maf? is check engine light on? and have you replaced 02 sensor latley?

how did it run when you unhooked maf did you drive it with it unhooked? is check engine light on? and have you changed 02 sensor latley?

man i need to quit replying to these threads i been up and working 24 ours.so no more replys tonight.sorry..:screwy: :screwy:

Have your catalytic converter checked.

yes I did drive with the maf unhooked, and there didnt seem to be really much difference, and yes the engine light is on, but has been for awhile now but this problem jus started recently, and no havent changed the 02 sensor, Im jus tyring to pin point the problem befor I just start throwing money at parts..

Popping sound. Can you elaborate on it? Maybe there is a problem with the boost bypass valve or a supercharger issue. Boost shooting up that high is obviously abnormal. Remove the supercharger drive belt and then see what it does. You can run with the SC belt off. It will act like a regular NA engine.

ok I tested the maf and it does run better unhooked, the problem is not as severe, but still there..and how do you unhook the sc belt? do you mean the surp belt off the pully?

are you talking about the s.t. belt that runs on all alt,water pump and so on?

yea that one, or is there a different one just for the sc?

yah s.b. that runs everything. and not hard to change. should look under your hood and it shows you how it too but it back on on a tag.

so will I need a different belt, being if the sc pully is not used the belt will need to be shorter?

where ever you go they will give the right size s.b. all you have to do is give them make and model and engine they will give you right belt. if you got a auto zone or advanced they will show you the belt you need and maybe even put it on for you. auto zone dose around here it's looks hard but it's not.

The main serpentine and supercharger (SC) drive belts are separate. Do not remove the main serpentine drive belt only the one for the supercharger. The SC drive belt has to be removed in its entirety to delete the supercharger or you will have a mess on your hands. See pic below.

http://i5.photobucket.com/albums/y186/lizzywiz/3800.jpg

Ok I un hooked the SC belt, and it did seem to make a little difference, but it still hesitates bad under load. I also did notice if I have it in park or nutral I can rev it all the way with no noticable effects, its just when I actually have it in drive this problem occurs??

have you checked vacuum? I think it should be around 18 inches at 2000 rpm's. Hold it at 2k, and watch vacuum. If it drops your cat is plugged.

BTW, have you ohm checked the TPS yet?

where would I find the vacume line to check this?

I have the same problem with my 98 gtp. I changed the maf sensor and the cat converter and it did not help at all. I took the sc belt off and now it runs good. So what would be wrong with the supercharger?

uh oh!

I have no clue what could be wrong, Bob or Rich will know for sure.

I will tell you that it would probably help to post the year, motor, and how many miles you have, just so the Mod's dont have to ask.

Could it be a bad coil pack? Also could it be spark plugs and or the wires.

Could it be a bad coil pack? Also could it be spark plugs and or the wires.

No, I think it has to do with the supercharger since when he removes the belt, it runs good.

I'm thinking possibly a bypass valve problem.