Is it the Fuel Pump or Fuel Pressure Regulator?

[JasonJ]

Hi All,

I have a 2001 L200 - 2.2 - 86,000 Miles. It will not start. I hooked up a fuel pressure tester - got 0 PSI when either turning the key to ON or trying to start it (but it might have been too little to show a result). Taking a shot in the dark I changed the fuel filter - no luck. I also swapped the fuel pump relay with the windshield wiper relay - no luck. I can hear the pump run for 3 seconds when the key is turned ON.

The two remaining parts that can cause this are the fuel pump and fuel pressure regulator. Do you know how to test either? Any thoughts on the fuel pressure regulator on these engines? Fuel pump reliability? A test method would really help.

Thanks!

Jason

[KLS1P]

When you put a fuel pressure tester on the fuel rail, and you hear the pump run for a few seconds, the pressure should come right up to 40+ psi. The pressure regulator comes into play when their is a vacuum applied to the regulator, also on the rail. Try hooking a vacuum pump (mityvac) to the regulator with the ignition on, and see if this causes pressure to show on the rail.

[fdryer]

Originally Posted by JasonJ

...2001 L200 - 2.2 - 86,000 Miles. It will not start. I hooked up a fuel pressure tester - got 0 PSI when either turning the key to ON or trying to start it .... I can hear the pump run for 3 seconds when the key is turned ON....

Is your factory security system disabled, the indicator light OFF with the ignition ON?

There's a flaw in your testing method; if a fuel pressure gauge were hooked up and you turned the ignition key to ON and you heard the fuel pump run for 3-seconds, there's usually pressure immediately developed and should have been indicated on the pressure gauge unless there's either a very large leak or the pressure gauge is broken. Or an incorrect hook-up not allowing any readings. Or the fuel pump didn't run at all for 3-seconds. Go over very carefully your testing method again and observe what you're trying to perform. Either the fuel pump runs during the ignition ON cycle for 2-3 seconds or it doesn't. Have someone else turn the ignition key while you listen; ear pressed to the car frame, screwdriver tip pressed on the fuel rail with the handle pressed to your ear, feeling the fuel line for vibration, etc.. The fuel pump cycling will only occur during ignition ON time and don't turn the key to START. Each time you try this cycle, wait 30 seconds between cycles otherwise you'll mistake a non-running pump when the PCM detects too many ignition ON cycles; the possibility of a very rare blown fuel line and constantly cycling the fuel pump as quickly as possible while troubleshooting, resulting in pumping fuel out where the leak is and now creating an explosion hazard. The PCM prevents this from occurring by simply disabling the pump circuit forcing a time-out between ignition ON cycles. In any other normal situation, you can start as many times as you like and as quickly too; another circuit is used to immedaitely turn on the fuel pump when the starter turns the engine over. The cps - search for an explanation as this doesn't enter into this problem.

Only one member recently posted less than 100,000 miles before his fuel pump failed. Saturn comfirmed it but we're still waiting on the final post, if this member does post any solution. This would be considered a premature failure in electric fuel pumps as they're designed for the life of a car and usually buried in the fuel tank for cooling and long term reliability.

If you're technically skilled you can paper clip a jumper between pins 30 and 87 of the fuel pump relay socket to apply immediate 12v power to the fuel pump, bypassing the safety designed ignition ON cycle. Be very sure of these two pins - one will be HOT 12v and the other is the line out to the pump. The pump is grounded elsewhere. The moment pins 30 and 87 are jumpered together the fuel pump should run and pressures indicated immediately. Be sure of the pressure gauge hook-up as an incorrect connection with the chance of possible leaks occurring immediately upon powering up the pump with a temporary jumper less than a few feet away creates the possibility of an ignition source - the small electric arc while jumpering the two pins and leaking fuel nearby from a poorly connected pressure gauge.

You can also ensure that 12v is on either pin and the fuse isn't blown. If using a fuel pressure gauge for the first time, try it on another car to be sure it reads pressures.