- Joined
- Oct 17, 2011
- Messages
- 755
- Reaction score
- 12
- Points
- 18
- Location
- New Joisey
- Vehicle Year
- 1987
- Make / Model
- Ford
- Engine Size
- 2.9L
- Transmission
- Manual
Was away for awhile but back. After some thought I was thinking fuel pump cause of how it ran till turned off. Got myself a fuel pressure gauge, got some baseline info when running well.Wish I had a wiring diagram for your rig--Does your 2002 have a relay, powering up the pcm/computer??--if so, replace it!! Almost sounds like your getting weird voltage, to the computer. I replaced a lot of these, and they caused really strange issues, some of which happened while the vehicle was running.--resistance in the relay,(or else where, if no relay) would trick the computer/make it think a restart had happened, when it didn't, and ect. Just a thought
Key on no crank it went ton 10 PSI
Key off then on, no crank went to 40 PSI
Key off then on, no crank went to 60 PSI
Key off then on, no crank no change, stayed at 60 PSI
Crank engine runs fine, holds 60 PSI
Stomp throttle drops to 55 PSI then back to 60 PSI within a second.
Went on my test loop, got problem to replicate.
Put pressure gauge on, showed 10 PSI when attached.
Key off then on, no crank no change, stayed at 10vPSI
Key off then on again, no crank no change, stayed at 10 PSI
Crank engine, runs very rough, pressure slowly drops stalls around 8 PSI
Came back up to 10 PSI after stalled
Hitting pressure release on gauge, goes to zero and the back to 10 PSI.
Not sure what holds the pressure. I let a small amount of fuel drain but came back although ignition off. Not sure how normal that is.
So thinking filter maybe but more likely pump cause filter shouldn't suddenly be a problem with a key off then restart. I can however see a pump off not restarting.
I am also wondering how it regulates pressure, if there could be a regulator problem or if there is a separate high pressure pump in addiiton to the main pump.