Car is having serious problems

[FAST87]

Okay the last couple days that I have been driving the GN has been up and down. If I WOT from a stop the retard degress is about 2 at the most. But everytime I seem to get on the highway and floor it it shoots up to 10 or even higher, and the O2's say 037. What is that? I don't hear any detonation when it reads that but I always back off the throttle. So last night I launched from a stop and as soon as the boost came in the car started to pop and stuter and there was 15 degress on the scanmaster. Again I immediately got off the gas. The car seems to run fine at any portion of throttle except full. I don't know what to do. Is there anyone in the chicago land area that is good at tuning these things?
thanks

 

[Dan Thompson]

Are you talking about 15° of knock?

What are your mods?

 

[FAST87]

Yeah sorry i should of said 15 degrees of knock. I turned the boost down even more and I still get like 7. Mods: PTE-44 turbo, V4 intercooler,poston headers,THDP,hooker cat back,42.5 inj, walbro 340 fuel pump, dual stage alchy, 160 thermostat, solid MAF pipe, and other litttle things. I thought that maybe the alchy isn't working. But i don't know.
later

 

[MARINES185]

if its poping and missing under boost its usually a sign of a weak
coil pack. it takes alot more spark energy to fire the plugs
under boost then it does during normal driving.

 

[FAST87]

But would a bad coil pack make the car have knock? The boost is at about 16# now and it still gets over 5 degress knock. Any other suggestions?
thanks

 

[sick GN]

Where in the Chicago area are u?? I'm just south west of Chicago in a suburb. I know some about these cars but am still kinda new to them still. But if u want to get together just email me and we can check things out.

Jeremy

 

[FAST87]

OKay well I took the car out this morning to see what else I could find out. The car runs perfect until I get to WOT. I did one blast, and as soon as the boost came in i got a pop from the motor and the knock went to 7. The car jolted for a second with the pop but that was it. I was about to let off right when it happened, but there was only one pop and after a second the knock went down to .5 degrees. So after a couple more seconds of WOT the knock went back up to about 4 and the pop came in again, so I immediately let off this time. I am not sure at all as to what I should be looking for. Something definetely isn't right. Any ideas?
thanks

 

[blackbuick87]

You have not said how much boost youre running, what chip and what is your base FP. Sounds like maybe a lean pop or coil pack

 

[Red Regal T]

Maybe not getting enough fuel. Possible clogged fuel filter or problem with the fuel pump.

 

[ChrisF]

What are your MAF values at WOT?

 

[FAST87]

Right now I am running about 17# of boost. The off line FP is at 42, and rises with the boost consitent. Not sure where the chip is from but it is a 108 with 26 degrees timing. I haven't even looked at the MAF values! What should they be at. I am gonna be taking the car out in about an hour so I can check on those.
thanks

 

[UNGN]

Originally posted by FAST87
Right now I am running about 17# of boost. The off line FP is at 42, and rises with the boost consitent. Not sure where the chip is from but it is a 108 with 26 degrees timing. I haven't even looked at the MAF values! What should they be at. I am gonna be taking the car out in about an hour so I can check on those.
thanks

The MAF values should be aroud 255 at WOT.

I hope you are running around 105-110 octane (leaded race gas) with a 108 chip at 17-18 psi. If you are running any less octane than this, you found your problem.

 

[blackbuick87]

108 chip on pump gas?

 

[FAST87]

Is there a better chip that i can get so I can run 93 with 19# of boost? The chip is actually a 110, if that makes any difference. When i bought the car about a month ago, the boost was at 19 and on 93 PUMP gas I got 0 knock. I even got 21# of boost with 1.7 knock at the most. Why is it now I get so much knock with the same fuel. At what degree of knock does it usually become loud enough where you can here it in the car?
Thanks for the help.

 

[UNGN]

Originally posted by FAST87
At what degree of knock does it usually become loud enough where you can here it in the car?
Thanks for the help.

This is something that doesn't have an answer.. kinda like: What does an anvil sound like when its dropped on your head?

 

[Red Regal T]

Originally posted by UNGN


This is something that doesn't have an answer.. kinda like: What does an anvil sound like when its dropped on your head?

THAT'S WHAT I WAS THINKING!

 

[ChrisF]

Im still waiting to see MAF values of at least 240....my car had a bad one, ran great except WOT....the MAF values never went over 180, causing the fuel map to starve the engine...Pep Boys had an AC/Delco reman unit for 90 bucks....problem solved...

ANY knock it BAD.....if you can hear it, it's already too late!

HTH

Chris

 

[FAST87]

UNGN: Well I took your advice yesterday and put in 7 gallons of 104 octane. Instantly the car seem to come back to life. No knock at 15#-20# of boost. The most knock I got was 0.7. I definetely will not be running anything less than 104 from now on. I still wanna know how the car ran on a couple gas tanks full of 93 with NO knock. I just hope that I didn't do anything to the car while it was on 93. I will be taking the car to get a dyno, once I install the Translator +, MAF, and PTE plenum and throttle body. What size should I go with on the TB? I was thinking that the 70mm is too big, so I would go with the 65.
thanks again