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Performance, Brainstorming & Tuning Talk about modifications, or anything else associated with performance enhancements. Have a new idea for performance/reliability? Post it here. No idea is stupid! (please use Detailing and Appearance for cosmetic ideas)

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Old 08-13-2007, 03:02 PM   #11
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I pretty much agree with what'* been said already.

Your trims and IPW'* say that your PCM thinks your air and fuel are properly balanced, however, your O2 voltage values say you're mega-lean. (0.850-0.880 is what I shoot for...cammed, you may want to aim slightly higher, like 0.870-0.900)

You are getting way lower MAF values (I assume the units are g/sec) than you should be, I think. I wonder if you can get your hands on a known good MAF sensor to swap in, just to rule out a bad MAF?

From the looks of things, either you're getting alot of unmetered air (massive vacuum leak) or alot less fuel than your PCM thinks (blocked filter/line, low fuel pressure/weak pump).
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Old 08-13-2007, 03:05 PM   #12
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Just talked to zommer, he agrees 100% low fuel pressure (more then likely due to old pump). Just talked to a company about a high flow 255, and looks like that will be ordered very soon along with a new filter. Then we will go from there. I agree with everything you said Andrew (pm me with some tuning ideas, for when i get this thing running decent)
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Old 08-13-2007, 03:06 PM   #13
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Yea, and i have about 3 MAF'* in the garage so i cantry that also.
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Old 08-13-2007, 03:36 PM   #14
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I would go stock replacement for the fuel pump. There is no reason to get a high flow one.
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Old 08-13-2007, 03:40 PM   #15
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Originally Posted by 95naSTA
I would go stock replacement for the fuel pump. There is no reason to get a high flow one.
The price is less than an AC Delco and in the future if he decides to tune via adjustable FPR it would be good to have as much pressure/fuel as possible.
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Old 08-13-2007, 03:49 PM   #16
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yea for the price, truthfully i can not, not get the high flow. I mean for an extra 20 dollars i would rather pay it just for piece of mind.
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Old 08-13-2007, 04:54 PM   #17
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Quote:
Originally Posted by BillBoost37
Quote:
Originally Posted by 95naSTA
I would go stock replacement for the fuel pump. There is no reason to get a high flow one.
The price is less than an AC Delco and in the future if he decides to tune via adjustable FPR it would be good to have as much pressure/fuel as possible.
Well, gmpartsdirect shows $112.44 for a stock replacement and Intense shows $124.99 for the 255 lph Walbro...

He could still bump up the fuel pressure with an adjustable regulator on a stock pump. I can't imagine you would NEED to upgrade the pump to see the fuel pressure needed to take advantage of better atomization.

Why go overkill and add another variable into the mix if you don't have to?
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Old 08-13-2007, 05:16 PM   #18
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With a stock regulator there is no additional variable. If he needs to add it he can.

It'* interesting that you are countering each thing this much Mike. This weekend TJ was worried that his car would even run with that cam because of your advice to him. We literally had to get it running before he would believe that he wouldn't require a different pcm eprom to run.
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Old 08-13-2007, 05:34 PM   #19
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Quote:
Originally Posted by BillBoost37
With a stock regulator there is no additional variable. If he needs to add it he can.

It'* interesting that you are countering each thing this much Mike. This weekend TJ was worried that his car would even run with that cam because of your advice to him. We literally had to get it running before he would believe that he wouldn't require a different pcm eprom to run.

I never said my car didn't run. It started to run crappy when it heated up. My car ran a whole lot better when I started to tune.
When ever I talked to TJ, all I ever talked about was getting a scan tool, getting comfortable with it, and get ready to tune right away. That is the single most thing I wish I had done differently.

I have been telling him to get that cam for years. I suggested ERs, 105'*, and various other things but I guess that'* bad advice too huh?

That stock pump had how many miles on it? I would rather put a stock pump in just for that reason. What'* the highest mileage on a Walbro?
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Old 08-13-2007, 06:02 PM   #20
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Perhaps look into the TPS thing. It may not be getting into PE?
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