View Full Version : ??? about fuel presure test

05-23-2003, 02:50 PM
I am about to perform a fuel pressure test under load..
I have a question though.. I know that at 0 vac i should have 39.5 psi out of fuel pump, and that it is a 1 -1 ratio with boost gauge. 1 0n vac is 40.5psi, 2on vac is 41.5 psi and so on..

Now my question is, if my fuel pump can't keep up w/ my throttle, how will the gauge act during the test.

My thoughts are if it is working fine it will rise steady w/ boost gauge, and if not working fine ---????I am guessing it will fluxuate?????

I can't seem to figure out thiss noise i am having at a WOT, but the good thing is, is that there are olny a couple more things it can be!!!!!lol:cool:

Help would be greatly appriciated, thanks!!!!!!:D

David Neibert
05-23-2003, 04:37 PM

If the pump can't keep up, the pressure will climb initially when you hit the throttle (normally 10 pounds of boost and 50 psi of fuel) , then as engine speed and boost increases the fuel pressure will either remain constant or start falling instead of increasing with the boost.

This could also idicate a restriction to the fuel flow, such as a clogged filter or pinched fuel supply line.


05-23-2003, 09:43 PM
Dave, once again, thank you for the information, it is an unbeleivable help.

I'm going to get right to it!!!!

Its great how much people help each other out here!!!!!:D