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Fuel issue

5K views 16 replies 5 participants last post by  jcroff 
#1 ·
I have a zex dry kit with a 255 in tank fuel pump. On the spray it lays down like its not getting fuel. On motor its fine. The 255 should be enough to spray 100 shot and keep up. Do I need an inline pump as well? Ideas? Btw ran 8.70s lifting in the 1/8th.
 
#4 ·
OOooh I was under the impression it was getting the bog as soon as u engaged the nitrous.. Have you had the car tuned at all and what RPM does it appear to be laying over? Roger
 
#5 ·
I hit it about 3ft off the line and the car pulls hard. Spins all first and hitting second (street tires) then high r's in second bogs. Pcmforless tuned it. I think its a valve float issue causing no compression, at least thats what it feels like. Theres no detonation of any kind which to me means its getting fuel. Adjusting the rockers is what im leaning towards plus its free!
 
#8 ·
Are u running the zex box or just the dry shot solenoid kit? I. Would raise bottle pressure to around 1100 and see what happens. If you set the bottle pressure at 900 and then sit for 20-30 min it will drop causing at power burst then fade off. You said you were going adjust rockers are u running stocks or rollers?
 
#10 ·
Have you checked fuel pressure on the car? The zex box works off nos pressure if the pressure drops so will fuel. Try on bottle the 1100-1200 starting psi with the rockers readjusted first and see what happens. Sounds like you may be dropping pressure.
 
#11 ·
does it nose over like the juice is shutting off or just a bit like it's losing pressure?

that pump should be plenty for a 150 shot even. is the fuel filter new or old?
 
#12 ·
update

moved to VA in aug so havent had time to test the spray at the track. However, i test sprayed it to about 80 on a road a little bit ago and didnt lay down. wont know until i find a track around here, and gota fill the bottle...
fuel pump is new and so is filter.....
 
#13 ·
How does that dry nitrous kit get the extra fuel needed to the motor? Do you have a tune thats just extra rich @ WOT to compensate?
 
#15 ·
what does the fuel pressure look like when on spray?

do you have a wideband O2 AFR gauge?

What do the plugs look like after a nitrous run?
 
#17 · (Edited)
Finally an update

Ok been a while heres some things ive done...i rechecked rocker arm they are good....i refilled the bottle...put in a new fuel sender......the problem I believe is fuel slosh?? My fuel guage was all over the place if it wasnt full. Around1/2 tank I noticed it would die out if I cornered hard just like it would on spray....i bought a fuel pressure gauge for inside the cabin and will be finding out for sure.

Ps its my daily so getting time to work on it comes rarely with a ft job and weekend side jobs thats y its taking me a while.
 
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