Running way lean first 2 seconds of spray. HELP!

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Dec 28, 2006 | 02:38 PM

Snake Eater

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From: Katy, TX

Running way lean first 2 seconds of spray. HELP!

I have a compucar dry kit with all braided stainless line and a single .073 jet. It bogs bad and goes way lean for about 2 seconds, then it hauls ***. How do I tune out this extremely lean spot? I doesnt matter what speed I'm going, its just the first 2 seconds of spray. Once it gets moving the O2's read a fairly steady .850-.875. I wish santa would have gotten me a wideband. lol

This is on my Yukon also, I figured you car guys had more experience with N2O.

Dec 28, 2006 | 04:08 PM

KrautBurner

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From: driving my 88 integra :(

just guessing (cause I'm a N00B)
but it sounds like your fuel pump is having trouble with the initial demand, then catching up

Nitro Dave's has some sort of an "accumulator" thingy

do you have any way of checking your fuel pressure?

Dec 28, 2006 | 04:41 PM

Snake Eater

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From: Katy, TX

I have a 255lph pump and 38.5# injectors. With spray there running 77% Duty Cycle max, so I know there is fuel. Its kind like the spray is going right past the MAF first or something.

Dec 28, 2006 | 05:43 PM

nate-roth

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From: houston, TX

Try doing a search for nozzle placement. Maybe you need to move it. Are you monitoring w/ a wideband? What is the A/F after the lean spot? Also could be in the readings of the maf, you may need to tweak the hertz readings while on the spray.

Dec 28, 2006 | 10:02 PM

Robert56

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From: Tacoma, WA

What exactly are you getting on your NB reading? Bogging from lean?
Two things to check.
Sounds like maybe nozzle placement is to far away, and/or wrong nozzle style, and/or nozzle not indexed towards MAF wire.
Nozzle(s) should be about 3 to 4 inches from MAF, using one or two 70* or 90* style nozzles, and indexed so as nozzle(s) is/are pointed directly at the MAF wire.
Make sure MAF wire is clean if running a oiled filter, as this can hamper MAF readings.
Also, make sure PE rpm activation is a little below your low rpm ws on as this can sometimes help a lean spike.

Dec 28, 2006 | 10:10 PM

Snake Eater

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From: Katy, TX

I got it fixed. I had the nosle pointed away and it was like the N2O was getting by the wires. Now it ROCKS! It spins all 4 wheels for 10 feet and the logger is showing 586 ft lbs. trans delivered TQ. It may not be 100% accurate, but N/A it only hits 295 ft lbs. It pulls harder off the line than anything I've ever been in. (excl. my one pass in my Z28 years back.)