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No fuel rail gas pressure
- Thread starter rangerman
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This tells me that you have fuel capacity, but the pressure to maintain that capacity is not there...
Since it starts then idles down then it starts the surges tells me there is a constriction or bent pipe reducing the needed flow to maintain idle and drive-ability.
So it tells me you might have a crushed or kinked line - it can only send at 2PSI but it will not shut off until it's met the right PSI for regulation to occur. But when it has a demand, it plays catch up and with the kinked line it's a losing battle when it requires a volume of fuel to maintain that pressure.
As a Checklist...
This may have already been addressed, but the Fuel rail should have a pressure switch or sender on the rail at or nearby those injectors - this condition sounds like the system can fill the rail - and it senses pressure, but then because of a constriction the fuel rail can't fill up fast enough to keep the injectors full to spray in fuel - so the engine starves...
Not too familiar with the fuel rail and delivery system on those Rangers, but I believe they used a manifold delivery system using an upper pipe to lower injector positioned draw-down delivery. That is; the fuel and the manifold - it has to have pressure sensor to know when to turn on and off the fuel pump - for the later models used a larger line to a splitter but then uses a low and high pressure combination switch near the front side opposite of the fuel line run so it sees these fuel demand variances and then sends the control signal as a feedback mechanism to help not just regulate the fuel pressure but also to provide the capacity and capability to adjust pressure to meet the demands on-the-fly.
So when you start the truck - or at least kick the starter to make the PCM think it's starting - can you hear the fuel pump start up? Try to bump the start function but not run the engine - It will then try to run the fuel pimp - whirr and run - then stop - should only be a few seconds - but if it's heard and runs for longer times - the system might be struggling to keep the fuel in the line (refueling or refilling that upper pipe manifold).
So if you can take some times to bump start the truck - can you also find the fuel pump relay? This trick is used for people doing oil changes on some vehicles they don't want to "idle up" during a oil-dry start after a change. This may help drain out the older fuel and kick the constriction or blockage down so it can free the line and work the sender units - its a lot like a water line feeding a fire hydrant - and the hose from that hydrant. IF the water line is only so large - but the hydrant is larger - it can still hold pressure when the water is not needed - but if the outlet hose going to the fire demands more - the hydrant can only supply that which the water line by volume (it's capacity) can provide.
Since it starts then idles down then it starts the surges tells me there is a constriction or bent pipe reducing the needed flow to maintain idle and drive-ability.
So it tells me you might have a crushed or kinked line - it can only send at 2PSI but it will not shut off until it's met the right PSI for regulation to occur. But when it has a demand, it plays catch up and with the kinked line it's a losing battle when it requires a volume of fuel to maintain that pressure.
As a Checklist...
This may have already been addressed, but the Fuel rail should have a pressure switch or sender on the rail at or nearby those injectors - this condition sounds like the system can fill the rail - and it senses pressure, but then because of a constriction the fuel rail can't fill up fast enough to keep the injectors full to spray in fuel - so the engine starves...
Not too familiar with the fuel rail and delivery system on those Rangers, but I believe they used a manifold delivery system using an upper pipe to lower injector positioned draw-down delivery. That is; the fuel and the manifold - it has to have pressure sensor to know when to turn on and off the fuel pump - for the later models used a larger line to a splitter but then uses a low and high pressure combination switch near the front side opposite of the fuel line run so it sees these fuel demand variances and then sends the control signal as a feedback mechanism to help not just regulate the fuel pressure but also to provide the capacity and capability to adjust pressure to meet the demands on-the-fly.
So when you start the truck - or at least kick the starter to make the PCM think it's starting - can you hear the fuel pump start up? Try to bump the start function but not run the engine - It will then try to run the fuel pimp - whirr and run - then stop - should only be a few seconds - but if it's heard and runs for longer times - the system might be struggling to keep the fuel in the line (refueling or refilling that upper pipe manifold).
So if you can take some times to bump start the truck - can you also find the fuel pump relay? This trick is used for people doing oil changes on some vehicles they don't want to "idle up" during a oil-dry start after a change. This may help drain out the older fuel and kick the constriction or blockage down so it can free the line and work the sender units - its a lot like a water line feeding a fire hydrant - and the hose from that hydrant. IF the water line is only so large - but the hydrant is larger - it can still hold pressure when the water is not needed - but if the outlet hose going to the fire demands more - the hydrant can only supply that which the water line by volume (it's capacity) can provide.
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