RICH Backfire?

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Apr 23, 2008 | 05:35 AM

Johnnystock

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From: Canada

RICH Backfire?

Small backfires are popping from my exhaust end around 5000rpm with 75pill and after it bugs out. My fuel pressure gauge is reading 71psi and 70 at wot??
I'm wondering if its my unequal fuel/n2o lines after noids that came with kit causing this(lines where where inverted in the installation pic/guide from HSW)

wet kit single nozzle,fpss,tr6 36gap,timing tuner

my car is reading 11.2 a/f ratio and 12.4 at wot n/a on crappy diablo tune.

Apr 23, 2008 | 11:22 AM

SY732

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What are you saying? that it is rich after you let off?

What lines are unequal the lines from the noid to the noz?

If so how long is each?

Apr 23, 2008 | 12:45 PM

99FRC

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Excess fuel burning off during deceleration will cause popping (technically backfire) from the exhaust. Is that what you're experiencing?

99 FRC

Apr 23, 2008 | 03:11 PM

Johnnystock

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sy732- line from fuel noid to nozzle:15inch and 20 for the N2O side.

99FRC- yes, it surges and after it seems excess fuel is burning off during decelaration and pops from the exhaust. and 70psi of fuel pressure. 1050psi on the bottle.

Apr 23, 2008 | 03:49 PM

Johnnystock

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one thing I'm sure is this happened at 5000rpm with 2degrees retard and it happened later at 5800rpm with 3degrees retard...
maybe its detonation and after its backfire from exhaust because lifting throttle??

I'll check my plugs

Apr 23, 2008 | 05:37 PM

Johnnystock

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forget about the fuel pressure;my gauge is stuck at 70psi unplugged

Apr 23, 2008 | 05:46 PM

SlayerMaro

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Backfire is when fire goes through your intake...hence the "back" part of backfire.

You are talking about afterfire.

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Apr 24, 2008 | 12:07 AM

SlayerMaro

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It's ok. But if this concerns you, I think a custom tune should help you out. Canned tunes work out for some people, but every car is different.

Apr 24, 2008 | 09:57 AM

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Johnnystock

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From: Canada

I figured it out: FPSS is cutting off the N2O,so I lift throttle and the afterfire happens. I just need a fuel pump asap. Something that will hold up to 600rwhp, racetronix or dual walbro, I dont know.