N2O Peeps, need help with a lean condition

[BLOWNDFIZ]

I took the N2O car to the track last night and no matter what I do I can’t get the thing to not run lean. I thought I had the issue fixed but last night it barely hit and the wideband showed 13 – 13.5:1 AF. I ended up shutting off the switch at ½ track so I didn’t break anything. The bad part is this was with only 800psi bottle pressure. The 2nd pass I even jetted the fuel jet higher than the nitrous (51F/46N). It still showed lean @ 800psi. The only thing I can guess is that the stock in tank pump is not pumping enough volume of fuel, but with the aux in-line it keeps the fuel pressure above the 35psi FPSS threshold.

Does anyone have any other thoughts at all? It seems like with most other LT1 guys their issues are never lean but way too rich. I know the wideband is accurate because last time I had it on the dyno the gauge in the car and the dyno wideband showed the same reading.

Anyway, your thoughts would be appreciated.

TIA

[MEAN LT1]

What do the plugs say?. Have you pulled any plugs to verify anything?

[BLOWNDFIZ]

What do the plugs say?. Have you pulled any plugs to verify anything?

Yes I have, but never right after a run and I didn't have a magnifying glass to look especially close. The plugs look normal, but then again 99% of the time I don't spray the car. They are all light tan, no specks out of the norm. I'm pulling 6 degrees of timing so I'm not too worried about things being hurt. I just can't get it to fatten up. I have a fuel pressure gauge, and I intend to look at it going down the track but always get fixated on the wideband.

Basically this thing has 134K miles and I am thinking it's fuel volume related. Does this even sound like a possibility to anyone else?

[Tony Shepherd]

I think you nailed it on the head. Fuel pump cant keep up and the FPSS is cutting off and on.

[BLOWNDFIZ]

I think you nailed it on the head. Fuel pump cant keep up and the FPSS is cutting off and on.

Looks like I have a Racetronix purchase in my future.

Thanks for the reply! I do appreciate it.

[Twisted Z]

what kit are your running?

[Chopstix]

I agree with Tony.....I always suggest upgradeing the fuel pump for any LTx car on nitrous.....even the newest stock fuel pump is now 12 years old ;)

[BLOWNDFIZ]

what kit are your running?

It started out as the LT1 dry kit from NOS, then I added the NOS dry to wet conversion. Basically it's a single fogger wet kit.
http://i238.photobucket.com/albums/ff44/BLOWNDFIZ/DSC_0041.jpg


I agree with Tony.....I always suggest upgradeing the fuel pump for any LTx car on nitrous.....even the newest stock fuel pump is now 12 years old ;)

So true! I knew I should have dropped the tank, but thought I'd band-aid the situation with the in-line that came in the kit. I don't know why I decided to skimp there.:doh:

[Chopstix]

FWIW an in-line pump can only push what the in-tank pump will flow.....they are used to maintain pressure not increase volume. If the in-tank pump can't keep up it will cause cavitation in the tank and severely decrease flow.

I am running the Racetronix kit and I left the NOS inline pump also. My car used to have the NOS dry kit on it before I bought it.

[BLOWNDFIZ]

FWIW an in-line pump can only push what the in-tank pump will flow.....they are used to maintain pressure not increase volume. If the in-tank pump can't keep up it will cause cavitation in the tank and severely decrease flow.

I am running the Racetronix kit and I left the NOS inline pump also. My car used to have the NOS dry kit on it before I bought it.

Really? You left the inline as well. I was thinking about that and almost decided to remove the inline and just go with the 255 in tank. What was your thought process on keeping both? I'm still trying to decide what to do.

[Chopstix]

Really? You left the inline as well. I was thinking about that and almost decided to remove the inline and just go with the 255 in tank. What was your thought process on keeping both? I'm still trying to decide what to do.

With the 255 in-tank I felt that the 255 in-line is just a little insurance.....didn't see where it could hurt anything.

I have made up to 566rwhp on that setup.

I am now running the nitrous kit off a seperate fuel system.

[BLOWNDFIZ]

With the 255 in-tank I felt that the 255 in-line is just a little insurance.....didn't see where it could hurt anything.

I have made up to 566rwhp on that setup.

I am now running the nitrous kit off a seperate fuel system.

Cool. I may just leave mine as well.