Outer Limits 4x4 Board

Is it true that this pump decreases the amount of fuel as the boost /rpm increases The adjustments done is 1 turn clockwise on fuelscrew and boost set to 16psi, Note, this is done just as a test. As the rpm increases, the boost does just the opposite, the peak boost (16psi at 1800rpm) is just 9 psi at 2800 rpm and the feeling when driving, is just as the fuel amount decrases. am gonna modify it using Gt3076 ext.w.gate turbo, 3" beaudessert exhaust, big FMIC, and just wonder if the pump needs to be removed from the truck and modified to overcome this

Look at the boost pin in the compensater, you may have to shim it to stop it going into a fuel reduction.


Andy

Do all pumps go into fuel reduction?

it works the opposite, the boost compensator reduces the amount of fuel available when off boost, as boost increases more fuel is added BUT once boost exceeds around 15psi fuel starts to be decreased again

the pump can be tweaked witout removing it. Tuning it is a fairly involved proccess. i had mine running great at up to 18-22psi.

search http://www.lcool.org" onclick="window.open(this.href);return false; for pump tuning info in the technical pages

Thanks for all answers

I know how the boost compensator works ie reduce fuel at low boost etc.. but maybe put a shim under the diaphragam/boost comp. helps to overcome the fuel reduction problem , because I only noticed it after I turned up the boost.

And being a 12mm plunger pump, I would have thought it would be capable of a fuel delivery of at least 100cc or so without any major internal mods

thanks again all