HELP!!! 90/90 change gone awry??
#42
TECH Apprentice
Thread Starter
iTrader: (2)
Join Date: Aug 2005
Location: Paxs River, MD
Posts: 335
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Originally Posted by Red99TA
You shouldn't be running that crappy w/o a tune. It sounds like something else isn't right like a vacuum leak or a sensor not plugged in maybe. I didn't change my tune at first when I put my 90/90 on and I wasn't running badly at all. Now I do have more mods/cam/etc but I can't imagine the tune getting that f-ed up just from an intake/tb. As mentioned you can pull a plug to see if it's running super rich. I would expect it to be leaner now that you're sending more air in anyways.
#43
TECH Senior Member
iTrader: (4)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Could be, have you tried posting in the tuning forum? Also, you could go over to the HPTuners or EFI Live forums and look for information there as well.
Is it drivable to a tuners?
One other question (I don't know the answer), there is some type of regulator in the fuel rail on the stock setup that you may have eliminated with the billet setup. Wondering if your fuel pressure is off in the fuel rails at idle. I thought fuel pressure was set at the pump in the 02's but am not sure. Is the stock fuel rail worth installing?
Is it drivable to a tuners?
One other question (I don't know the answer), there is some type of regulator in the fuel rail on the stock setup that you may have eliminated with the billet setup. Wondering if your fuel pressure is off in the fuel rails at idle. I thought fuel pressure was set at the pump in the 02's but am not sure. Is the stock fuel rail worth installing?
Last edited by vettenuts; 04-19-2007 at 08:39 AM.
#44
TECH Apprentice
Thread Starter
iTrader: (2)
Join Date: Aug 2005
Location: Paxs River, MD
Posts: 335
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Originally Posted by vettenuts
Could be, have you tried posting in the tuning forum? Also, you could go over to the HPTuners or EFI Live forums and look for information there as well.
Is it drivable to a tuners?
One other question (I don't know the answer), there is some type of regulator in the fuel rail on the stock setup that you may have eliminated with the billet setup. Wondering if your fuel pressure is off in the fuel rails at idle. I thought fuel pressure was set at the pump in the 02's but am not sure. Is the stock fuel rail worth installing?
Is it drivable to a tuners?
One other question (I don't know the answer), there is some type of regulator in the fuel rail on the stock setup that you may have eliminated with the billet setup. Wondering if your fuel pressure is off in the fuel rails at idle. I thought fuel pressure was set at the pump in the 02's but am not sure. Is the stock fuel rail worth installing?
#45
12 Second Club
iTrader: (8)
Join Date: Jul 2004
Location: Vancouver, BC
Posts: 708
Likes: 0
Received 0 Likes
on
0 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Originally Posted by shooter
Now my idle seems to be all over the place and the car is spitting and sputtering.
Search in the tuning section on the details of a 90/90 swap and what it does to your RAF tables and how they effect idle, as well as throttle position adjusting, and drilling the TB blade..
#1 you have to modify your Running Airflow Tables by 48% to accomodate for the new size TB and Intake,
#2 you then have plenty of idle tuning to tweak it just right. Prob have to drill the TB as well.
granted a lot of this is also done with the cam swap, but the intake and TB have a lot to do with this as well.
Just my op
#46
TECH Apprentice
Thread Starter
iTrader: (2)
Join Date: Aug 2005
Location: Paxs River, MD
Posts: 335
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Well I'm going to go back to stock tonight and have it put back on when I change my heads/cam in tuning at the end of may, I'll post up and tell you guys how it running on friday when I'm done putting it back to the basics.
#47
TECH Fanatic
iTrader: (2)
Join Date: Jul 2004
Location: Greensburg,PA
Posts: 1,882
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
do you have clearance between the manifold/ tb and the front coolant crossover pipe on the head? did you bend it down before installing the manifold, if not, your intake is sitting on that pipe and not fully seated, thus a vac leak which would cause the serging.
#49
TECH Apprentice
Thread Starter
iTrader: (2)
Join Date: Aug 2005
Location: Paxs River, MD
Posts: 335
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Never thought about about that line, I'll be checking it out before I pull it off tonight. Now that I think about it that line was already there when I put the intake on and It may have been hitting it enough to not let it seal to the heads.
#50
Launching!
Join Date: Apr 2007
Location: College Station, TX
Posts: 264
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Sorry for the little detail, but what are you trying to idle at? The FAST 90 has a "Basic Operating RPM Range" of 1800-6000 RPMs. I don't have one and I'm not an expert, but I would assume that there would be choppiness in a 1.1k idle.
#51
TECH Apprentice
Thread Starter
iTrader: (2)
Join Date: Aug 2005
Location: Paxs River, MD
Posts: 335
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Originally Posted by Shock Hawk
Sorry for the little detail, but what are you trying to idle at? The FAST 90 has a "Basic Operating RPM Range" of 1800-6000 RPMs. I don't have one and I'm not an expert, but I would assume that there would be choppiness in a 1.1k idle.
#52
TECH Senior Member
iTrader: (4)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
It should idle normal, don't think that is the issue. Your plugs are indicating a very rich condition that isn't being compensated for by the O2's. Seems to indicate unmetered air, i.e., vacuum leak.
I have been searching and several do mention you have to alter the shape of the forward cooling line between the heads. If this is an issue, let us know.
I have been searching and several do mention you have to alter the shape of the forward cooling line between the heads. If this is an issue, let us know.
#53
TECH Apprentice
Thread Starter
iTrader: (2)
Join Date: Aug 2005
Location: Paxs River, MD
Posts: 335
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Originally Posted by vettenuts
It should idle normal, don't think that is the issue. Your plugs are indicating a very rich condition that isn't being compensated for by the O2's. Seems to indicate unmetered air, i.e., vacuum leak.
I have been searching and several do mention you have to alter the shape of the forward cooling line between the heads. If this is an issue, let us know.
I have been searching and several do mention you have to alter the shape of the forward cooling line between the heads. If this is an issue, let us know.
#55
TECH Addict
iTrader: (11)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Even if you do have the LS6 style front intake tube (required) then it still may keep the intake from sealing to the heads...I know because mine did. What I ended up doing was getting my hammer and tapping the tube down using a rag to soften the blows. I got it to move down by about 1/2" which was enough to allow the intake to seat properly.
#57
TECH Senior Member
iTrader: (4)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Originally Posted by Red99TA
Even if you do have the LS6 style front intake tube (required) then it still may keep the intake from sealing to the heads...I know because mine did. What I ended up doing was getting my hammer and tapping the tube down using a rag to soften the blows. I got it to move down by about 1/2" which was enough to allow the intake to seat properly.
#59
TECH Apprentice
Thread Starter
iTrader: (2)
Join Date: Aug 2005
Location: Paxs River, MD
Posts: 335
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Well I couldn't find dam thing wrong with it, so i'm take it back off, and have it installed with my heads/cam package that I just order from texas speed (Precison Race Components Stg 2.5 5.3L Heads & Cam, torque 2 232/234, 595 intake, 598 exhaust, 113 and a yank SS3600, the install will be on 30th May, so that's when the really fun will starts.
Thank-you agian for all the help everyone!!!
oh I brought it by a friends house and I was black smoke and looked to be running rich as hell
Thank-you agian for all the help everyone!!!
oh I brought it by a friends house and I was black smoke and looked to be running rich as hell