I have a '86 Bronco fuel injected 5.0L with manual transmission. The engine runs fine with the tranny in neutral or the clutch pedal pushed in. I can rev up as high as I want. However, as soon as I start to let out the clutch, I lose fuel pressure (I put a gauge on the manifold schraeder valve) and the engine dies. This happens whether I go forward or backward. I have bypassed the fuel cutoff inertia switch. I don't see fuel pressure again until I cycle the key back to the "OFF" position and then back to "ON". I can then crank the engine and it starts right back up. Any ideas?

 

you either have a stuck injector, bad fpr or your fuel pump is going out. what is your fuel pressure at the rail with just the key on and the engine off?

 

Was there anything that happened before this started anything strange or did you recently replace anything?

 

Key-on Engine-off fuel pressure is 38 psi. This doesn't change when I start the engine.

I have not done any work on the truck since this started happening. I forgot to mention that I did tried installing a new fuel pump cutoff relay to solve this problem, but it had no effect.

 

AND for my standard fuel related question answer!!! Dedicated gas line dryer when you put it under load it pulls more fuel swirling up the water in the fuel filter, fuel rail,
etc. Water has a high surface tension and it could block the small orifices in the injectors and a partially clogged fuel filter. Stop at the parts store grab a couple of bottles of heet and maybe a fuel filter.