The fuel pressure goes down. And the car dosen't get so much fuel like it should?

1994 NISSAN 200SX
93,205 MILES
Avatar
ERICO0
  • MEMBER
  • 3 POSTS
Hello :) I hope you can help me. I have a problem with my car. When I have full throttle on the gas. The fuel pressure goes down. And the car dosen't get so much fuel like it should. I changed the fuelpump 2 weeks ago. And the fuel filter 4 months ago.

But if I turn on and of the egnition. The problem is gone. And after a while it comes back again.
Jun 4, 2013 at 9:43 AM
Advertisement
Avatar
JACOBANDNICKOLAS
  • CERTIFIED EXPERT
  • 110,175 POSTS
Check the fuel pump regulator to make sure it is working.
Jun 4, 2013 at 10:51 AM
Avatar
ERICO0
  • MEMBER
  • 3 POSTS
I have changed the fuel pressure regulator and the prussure on idle is like it should be.

I also changed the pump for 1 month ago. And after I changed it, the problem took longer time before it came ( Like 20 minuts ). But now it like before i changed it and it only takes 5-10 minutes befor it comes up.

I have changed the sparkplugs, tested other coilpacks, searching for boost leaks, and much more. But I can't find out the problem. :(
Jun 4, 2013 at 3:48 PM
Advertisement
Avatar
JACOBANDNICKOLAS
  • CERTIFIED EXPERT
  • 110,175 POSTS
When you are checking the fuel pump pressure, is it within spec when you open the throttle fully for a second?
Jun 5, 2013 at 10:03 AM
Avatar
ERICO0
  • MEMBER
  • 3 POSTS
No, at the same time I give full throttle it only goes more and more down all the way down to 29 psi. On idle the car should have 36 psi. And it have, but that tells you how much it's going down. Normaly it will go between 36 psi and 50psi when I full throttle.
Jun 5, 2013 at 12:13 PM
Avatar
JACOBANDNICKOLAS
  • CERTIFIED EXPERT
  • 110,175 POSTS
Based on what you are telling me, it sounds like the pump can't keep up with the demand.
Jun 6, 2013 at 4:17 PM