SS M90 kit for grand prix ?

[grandprix00]

Hi im having problems with this kit im getting werid long tirm fuel trims with and just wanted to know if anyone had any problems with this. my long trim fuel trim is -14 average. I have the right fuel presure set up as they told me. I know when its negative its adding alot of fuel and its causing a miss fire but when i drive it the scan tool shows that the miss fire is gone and one of my friends told me i should put on a valve cover breather will that help it out? He said i might have too much pressure in the crank case thats causing me to go threw the top intake gasket where the intercooler goes on the supercharger? Im just at the point where i just need some ideas to look for.

Here is my set up
ss m90 kit on 2000 grand prix gt
3.5 pulley with 42.5 injectors
stage one gt cam from zzp
#90 valve spring
zzp fuel rail
cold air intake
egr delet kit
ss intercooler
msd wire
bosh +4

[tblake]

I always thought long term fuel trim numbers like -14 means that the system is subtracting fuel to compensate for an overly rich mixture.

[BNaylor]

Originally Posted by tblake

I always thought long term fuel trim numbers like -14 means that the system is subtracting fuel to compensate for an overly rich mixture.

Assuming we re looking at -14% which is what a typical scan tool reads out, i.e. percentage. On Long FT a positive percentage means the PCM is adding fuel to compensate for a lean condition. A negative percentage means the PCM is subtracting fuel for a rich condition. Although based on ideaology the goal is to keep LTFT as close to zero as possible to maintain that ideal 14.7:1 air/fuel mixture ratio. And of course short term fuel trim (STFT) affects LTFT.

Is this PCM module properly programmed for the 42.5# fuel injectors?

[OJ_]

Couple things you need to check:


Vacuum leaks can cause your LTFTs to be in the deep negative range. Do your LTFTs stay negative or go back towards 0 when you are accelerating?

Which version of the ss M90 kit do you have? Your PCV functionality may be inhibited by the intercooler itself therefore requiring a breather. I am just throwing this out there, if you are referring to the ZZP SSIC kit you may want to verify PCV operation.

I am not sure how your are acquiring your trims, are you using some type of scanner? You may need to tune your MAF table among other things.

Peace man.

[grandprix00]

Well yes the computer is programed to everything that i said that i put on there for mods. and im useing the mentior scan tool. when im driving down the highway or just going like 20mph all the miss fires go to zero it doesnt show that its missfiring at all so that must be a intake gasket leak and i heard that them green ones from zzp dont work too good for the top of the intercooler that everyone uses the oem style anyone heard of this.

[BNaylor]

Originally Posted by grandprix00

i heard that them green ones from zzp dont work too good for the top of the intercooler that everyone uses the oem style anyone heard of this.

Are you referring to the Garlock SC gasket? I've heard nothing but negative comments about them some too graphic to post.

Also, have you run an engine vacuum check?

[grandprix00]

Originally Posted by BNaylor

Are you referring to the Garlock SC gasket? I've heard nothing but negative comments about them some too graphic to post.

Also, have you run an engine vacuum check?

no havnt done a vacuum check yet ive just been spraying carb cleaner around the upper gasket and watching the o2s on the scan tool. Have you heard of a vacuum leak cause it to put long term fuel trims in the negative tho.?

[OJ_]

Originally Posted by grandprix00

Have you heard of a vacuum leak cause it to put long term fuel trims in the negative tho.?

Yes, vacuum leaks can put your LTFT's into negative. ANY unmetered air(not going through MAF sensor) will cause fueling issues. Look at it this way. The MAF sensor meters the air ~informing the PCM of the amount of air coming through. The PCM injects what it believes is the correct amount of fuel to create combustion. The exhaust gases of the resulting combustion exit your engine and go by the o2 sensor. The O2 sensor measures the extent of the combustion to see if there was too much air or too much fuel and than reports to the PCM. Essentially, your PCM is getting conflicting values. The PCM tries to correct the issue by pulling fuel or adding fuel depending on what the problem is. Resulting in positive or negative trims. Unless your MAF table is really screwed up or your MAF sensor is bad, you most likely have some type of vacuum leak.

and yes, Garlock gaskets at least for our cars should be avoided.

Did you install your intercooler yourself?

[grandprix00]

Originally Posted by OJ_

Yes, vacuum leaks can put your LTFT's into negative. ANY unmetered air(not going through MAF sensor) will cause fueling issues. Look at it this way. The MAF sensor meters the air ~informing the PCM of the amount of air coming through. The PCM injects what it believes is the correct amount of fuel to create combustion. The exhaust gases of the resulting combustion exit your engine and go by the o2 sensor. The O2 sensor measures the extent of the combustion to see if there was too much air or too much fuel and than reports to the PCM. Essentially, your PCM is getting conflicting values. The PCM tries to correct the issue by pulling fuel or adding fuel depending on what the problem is. Resulting in positive or negative trims. Unless your MAF table is really screwed up or your MAF sensor is bad, you most likely have some type of vacuum leak.

and yes, Garlock gaskets at least for our cars should be avoided.

Did you install your intercooler yourself?

yes i did i put rtv around the inside of the plate like zzp told me too and i dont know maybe this weekend ill try and put a oem style gaket on the top see if that help out. DO u know where the vac line suppose to go on the ss m90 kit i have it a T off from the intake going to the maf and the other vac line going to the fuel reg. Zzp pics look like they have the vac line to the maf to TB. but when i do that it doenst look right on the scan tool for presure that its reading so i just left it on the the T fiting from the lower intake. will the tb screen have anything to do with this too i took my off maybe i should put it back on becuase i heard it sometimes messes with fuel trims.

[OJ_]

Originally Posted by grandprix00

yes i did i put rtv around the inside of the plate like zzp told me too and i dont know maybe this weekend ill try and put a oem style gaket on the top see if that help out. DO u know where the vac line suppose to go on the ss m90 kit i have it a T off from the intake going to the maf and the other vac line going to the fuel reg. Zzp pics look like they have the vac line to the maf to TB. but when i do that it doenst look right on the scan tool for presure that its reading so i just left it on the the T fiting from the lower intake. will the tb screen have anything to do with this too i took my off maybe i should put it back on becuase i heard it sometimes messes with fuel trims.

Sorry about the late reply.

Put the MAF screen back in. The function of the screen to to 'straighten' out the air so it achieves a type of consistency before it travels by the MAF sensor. If the air is becoming turbulent or inconsistent if it definately cause issues. If I were you I would reinstall it immediately, there is no appreicable performance gain out of leaving the MAF screen out, definately not enough to compensate for the problems it can cause.

[grandprix00]

Originally Posted by OJ_

Sorry about the late reply.

Put the MAF screen back in. The function of the screen to to 'straighten' out the air so it achieves a type of consistency before it travels by the MAF sensor. If the air is becoming turbulent or inconsistent if it definately cause issues. If I were you I would reinstall it immediately, there is no appreicable performance gain out of leaving the MAF screen out, definately not enough to compensate for the problems it can cause.

Did that no change little better on the fuel trims but still kinda out of wak going to try a smoke test on in again check for vac leaks for some reason i keep having problems with the intake not sealing up right even use rtv the right stuff idk ill find out this weekend and will keep you updated thanks for the help so far

[grandprix00]

Originally Posted by grandprix00

Did that no change little better on the fuel trims but still kinda out of wak going to try a smoke test on in again check for vac leaks for some reason i keep having problems with the intake not sealing up right even use rtv the right stuff idk ill find out this weekend and will keep you updated thanks for the help so far

okay found out whats making it all werid bought a pack of smokes this weekend and took a vac line and smoked it and found out supercharger intakes leaking but guess what ive already put in 6 intakes gaskets and use rtv the right stuff and still not working out for me whats i heard about using metel intake gaskets i heard people are using them any advice on it or where to get them.? oh yah even tryed oem style and no dice on that.

[OJ_]

Originally Posted by grandprix00

okay found out whats making it all werid bought a pack of smokes this weekend and took a vac line and smoked it and found out supercharger intakes leaking but guess what ive already put in 6 intakes gaskets and use rtv the right stuff and still not working out for me whats i heard about using metel intake gaskets i heard people are using them any advice on it or where to get them.? oh yah even tryed oem style and no dice on that.

Did you follow the correct bolt tightening sequence as well as the correct torque on the bolts? In any respect, you really need to follow the correct sequence along with torque specs.

When you say "supercharger intakes leaking" are you talking about the actual intake into the supercharger or are you talking about the lower intake manifold.

[grandprix00]

Originally Posted by OJ_

Did you follow the correct bolt tightening sequence as well as the correct torque on the bolts? In any respect, you really need to follow the correct sequence along with torque specs.

When you say "supercharger intakes leaking" are you talking about the actual intake into the supercharger or are you talking about the lower intake manifold.

yah did all the torque and sequence i kinda got it memorized by how many time ive done it and im talking about what the supercharger bolts up to the intake i took the intercooler off and b.c i got sick of replacing 2 gasket everytime and i thought i just find this out now and go from there.