View Full Version : Instant 25 psi fuel pressure drop, whats the cause?

06-17-2005, 09:22 PM
My fuel system had developed a quark. At 5200-5300 rpm my fuel pressure drops from 65-40 instantly. Same spot in the rpm everytime. I havn't changed anything in the system and it used to hold pressure just fine all the way to 6500 rpm. Both pumps are coming on. Any ideas what would cause this?

06-19-2005, 12:58 PM

MW2 Performance
06-21-2005, 11:50 AM
You may have a bad injector, or wiring harness, or the pcm/ yadda yadda, What it sounds like to me is with my experience on my injector cleaning machine, sometimes when I am cleaning a set of injectors that are faulty(either mechanincaly or by contamination) on certain frequencies they will get locked in the open position, and dont come unlocked untill a different frequency is reached, but it could be numerous things.


06-21-2005, 07:24 PM
do u have dual intank pumps if so one of the lines from one of your pumps may have a small leak or tear causing you to lose pressure.

06-21-2005, 10:07 PM
I've looked at the lines on the pumps and they seem Ok, but I'll double check. It's just wierd to me how it's such an instant drop, and always the same rpm. I don't think the injectors lock open cause the car leans out when the pressure drops.