How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Randall C Your Own Question
Randall C
Randall C, ASE Certified Technician
Category: Car
Satisfied Customers: 12803
Experience:  32 years Foreign / Domestic Cars All aspects of Diag and Repair
Type Your Car Question Here...
Randall C is online now
A new question is answered every 9 seconds

97 olds bravada: 14 psi at fuel filter, no fuel at return side bleeder

Customer Question

97 olds bravada, no fuel to TB, 14 psi at fuel filter, no fuel at return side bleeder
Submitted: 6 years ago.
Category: Car
Expert:  Randall C replied 6 years ago.
Chat Conversation Started
Tracer :

Hello, the fuel pressure is to be 60-66 psi and not only 14 psi. the test port on the fuel line/rail is not on the return side but on the pressure side. if you only have 14 psi at filter, suspect bad fuel pump or one leaking back.You need to see 60-66 psi at the Tb

Tracer :


Ignition On, Engine OFF415 - 455 kPa (60 - 66 psi)
Tracer :


Circuit Description
When you turn the ignition switch ON, the Vehicle Control Module (VCM) turns on the in-tank fuel pump. The pump remains on as long as the engine is cranking or running and the VCM is receiving reference pulses. If there are no reference pulses, the VCM shuts off the fuel pump within 2 seconds after you turn the ignition ON or the engine stops.

An electric fuel pump pumps the fuel through an in-line filter to the Central SFI unit. The pump is attached to the fuel level meter assembly inside the fuel tank. The pump is designed to provide fuel at a pressure above the regulated pressure needed by the injectors. The pressure regulator keeps the fuel available to the injector at a regulated pressure. Unused fuel is returned to the fuel tank by a separate line.

Diagnostic Aids
Tools Required, J 34730-1A Fuel Pressure Gage in J 34730-E or J 34730-IA Fuel Pressure Gage with J 34730-250 Fuel Pressure Adapter Kit.

Customer: replied 6 years ago.
<p>ok, the car was running fine when parked bout a year ago, I put 10 gallons of fresh fuel in it & jump started it, it started right up, purred like a kitten, it ran bout 5 mins & died & would not restart, I sprayed a lil gas in the intake & it started briefly, when I changed the fuel filter the line to the motor did not clip properly & when I had my son crank the motor it was leaking pretty good then it blew the line off the filter nipple & a steady foot & a half stream of gas was shooting out, due to the stiffness of the hard plastic line I had to take the in line off to get the out hose back on, so this indicates it took alot of pressure to blow the line off of the filter nipple, now there is absolutely nothing at the bleeder (air or fuel) when cranking the motor, is it possible that the line could be that clogged?</p><p>btw I had read on another site that the bleeder nipple was on the return line </p>
Expert:  Randall C replied 6 years ago.
All I can add is if you have fuel running out of fileter side to engine and none at the pressure test port, then either the presure is weak, volume not there or yes a bad line but rarely seen than happen. On this engine, the testport is on the pressure side of the fuel meter. This is how you test to see if fule is getting at least to the fuel meter and not a problem after it. It really does not take much to push a line off a fliter that was not snapped correct. The real only way to confirm all this is to hook up pressure guage at the test port. You need minimum of 60 psi. If you do not have one, some parts stores rent them pretty cheap or can buy cheap on as well
Customer: replied 6 years ago.

you keep telling me to check the pressure, but if there is nothing at the test port/bleeder, what is a gauge going to do? talked to my Dad today & he said put a hi pressure (90psi) external pump in between the filter & the motor, we both tend to agree that it is unlikely that the line could be so clogged as to not allow even a small amount of fuel, will an external pump work or have u ever seen this done?

Expert:  Randall C replied 6 years ago.
In a way you are correct but you stated 14 psi so i was assuming you had some way to check pressure. Wanted you to hook up guage and then we could move on to tapping into the pump and jumping it to see if we can build up pressure. It is possible from sitting, sediment developed in tank and may? be blocking the pickup screenn at the bottom of fuel pump. This could explaine and low pressure you may have.You can not hook up and inline pump. First off the head pressure needs to be around 120 psi, sencond, the pump will not draw fuel through the pum in the tank like that. #rd is the volume of external pump. I do not remember volume needed but it is high so you always have adequate fuel.Chances are you will have to drop the tank to do a fule pump.I relaize you want a way around this but would be wasting your time with external pump.It just cant draw through the tank pump like you think it would
Customer: replied 6 years ago.
ok heading back to Ca. today where the car is, tomorrow I will find a gauge & check pressure first off at the bleeder, although I dont expect to get a reading because when depressing the shrader valve on the bleeder I get absolutely nothing when cranking the motor, even though I am getting fuel pressure past the filter, even if its not enough to run the vehicle it should at least push fuel to the bleeder? this is what I dont understand. I will then check it at the filter, yes I hate to drop the tank & replace the pump only to find that was not the problem, been there done that once already with my truck. I do appreciate your patience with me, & I will go ahead & submit my payment regardless of the outcome, just hang with me another day untill I can get the pressure tested, once again thank you.
Expert:  Randall C replied 6 years ago.
LMK. Even if say the regulator is bad allowing fule to loop right back, you will still get a small amount of fule out of schrader. I am still thinking you are seeing very minimal pressure and its kind of disapating before the engine do to lack of volume. I could be arong but.. if there is fule pressure it WILl come out schrader in some fashion. Lmk thanks