QuestionI am getting mixed info from people and do not have the right tech manual. What should the operating fuel pressure be in the fuel rail? How sensitive is that pressure as to whether the car will start? The car ran fine one day, it sat for two days and the temps dropped to just beloew ZERO and the car ahs not started since. I have it in the garage not and it still wont start. Compression is decent with some variation, plugs are single point platnum with 50K miles on them. This is the first time in its life that this car failed to start and there were no problems building up to this. Just happened.
AnswerHello Dan,
If the car has throttle body injection,the pressure should be 9 to 14 PSI. I like closer to 14, say 13PSI.
If the engine has MPFI,(multi-port fuel injection), or sequential fuel injection,(SFI), then the pressure needs to be between 41 and 47 PSI.
Don't let the parts house say they use the same pump.
Well, for sure there needs to be some pressure, since the injectors are just solenoid valves, and depend on the pump pressure to push the fuel through them when they open.
If you want to check for ignition, etc, you can remove the air cleaner hose, and spray just a little starting fluid, or some gasoline, and see if it hits. Be careful to have some ventilation though if you do it in the garage, especially if there is a gas water heater nearby.
Of course, you could use a spare spark plug connected to a plug wire, and grounded to check for spark.
You should be able to hear the pump running in the tank for three seconds after the key is turned to run.
If there is any water in the fuel, it could have frozen and prevented the pump from operating, although in the garage it should have thawed out.
Possible it blew the fuse though if it was frozen, so check that.
Good luck,
Van
