HELP!!! 90/90 change gone awry??
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From: Paxs River, MD
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.
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; Apr 19, 2007 at 08:39 AM.
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From: Paxs River, MD
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?
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
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From: Paxs River, MD
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.
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.
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From: Paxs River, MD
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.
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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.
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From: Paxs River, MD
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.
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.
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From: Paxs River, MD
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.
If it turns out that the forward cooling line is the issue, don't try and pry it I am afraid it might crack the intake. You will likely need to remove to fix it properly.
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.
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.
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From: Paxs River, MD
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