f8b fuel problem

[KeVl@r]

hey guys im a new member and for a wile my mightyboy has been running rough and seems to be starving for fuel
it has a hollie blue fule pump and 2 regulators i thought that it would do the trick but about $600 later still not runnin right does any1 know what the problem could be

[Brayden]

Start with a fuel pressure guage and test that there is about 5PSI at idle and about 5PSI constantly higher than your boost pressure through the RPM range.

[KeVl@r]

yer i tryed that and still dosent want 2 run properly im gonna try gettin bigger injectors see if that helps

[hatch4play]

with a injected setup wouldn't you want like 30psi with rising rate fuel regulator? 5psi sounds right for a carby turbo setup!

[hatch4play]

also its a dumb question but you are not running your fuel line through the old fuel pump are you?

[KeVl@r]

yer i only got the hollie fuel pump and i got 2 return lines back to the tank but i dunno what's wrong

[Brayden]

Yeah I mean without knowing ANYTHING about the setup of the motor I had to take a guess that it was carby. Being an F8B that was a logical assumption.

[KeVl@r]

ill just have to try a bigger carb or new injectors or sumfin coz i dont no what else 2 do

[hatch4play]

what computer are you running?
Have you had it dynoed to see where it is leaning out?
Do you have a stoichmeter(fuel mixture metre)?
If not how do you know it is leaning out? Is it pinging?
Does it only do it after a while?
do you have a air temp gauge? or even intercooler?
these will help identify the problem!

cheers jimbo

yeah thats cool brayden i would have assumed it too until he posted back after your reply that he might need bigger injectors!

[KeVl@r]

im pretty sure it is leaning out because it seems to only do wen im in boost i think it is the back pressure of the turbo not lettin enough fuel in because it seem like its starving for fuel but at idle and low revs its fine

[KeVl@r]

oh and yes i do have an intercooler of a standard 200 sx

[hatch4play]

yeah well you need to get a air temp meter, you can get digital ones from jaycar for around $30 put that in the inlet near manifold. and check your inlet temp! (you may be putting too hot air in the engine) in that case a intercooler and a pound or two more of boost will help.

Also get a dyno done they will register the fuel mixture through the range and tell you what is going on.

but you need to answer some of my questions in the previous post before anyone will be able to help really.

[KeVl@r]

i was gonna get a dyno run but ive been to busy to find the time but i might just do that thanx

[Brayden]

So lets get this straight...

You have a carby and you think you need to upgrade the injectors? Good luck with that mate.

[KeVl@r]

no i mean bigger carby jets so it flows more fuel