I know what you're thinking. It's loosing prime. Rebuild filter housing and/or check fuel hoses, put a FASS on it. Stay with me.
1) Dad owned truck for 3 years. He removed the factory fuel filter assembly and put a BMP "lift pump" filter housing on it. Never experienced this he says. He towed a ~10k 5th wheel camper. (He also doesn't live near much elevation change.)
2) We got truck a year ago. No issues observed.
3) June, we bought a ~9k 5th wheel camper. I replaced every coolant line, fuel line, and hydraulic line under the hood to solve some weeping fuel lines in the valley. July 4th, took first trip with camper. Headed into the hills on a hot day with AC on max. No issues.
4) Got home, changed fuel filter as PM.
5) Very next trip. Arrived at campground. Backed into spot. Unhooked camper. 15 minutes later, restart, truck cranks, runs for a few seconds, and stalls before I can put it into gear. I figured residual air in the filter. Lift pump was running. I purged from test port and got it to start.
6) Came home, did the same thing after we unloaded. (Probably 90 minutes of heat soak time.)
7) Subsequent camping trips, same thing on hot restarts. Starts, runs for a few seconds, and stalls before I can put it into gear. Eventually it will restart. Sometimes right away. Sometimes after a few tries.
Casual observation is that I didn't get the new fuel filter on right, and it's sucking in air. Read on.
Additional info:
My theory is that the fuel pressure regulator is in the earliest stages of going bad. It takes lots of heat in the CP3 to cause it to act up. When hot, the plunger doesn't move easily and causes the typical oscillation of a bad CP3 FPR. Somehow it's fine when running, but shut it off and restart, it oscillates and hangs so bad it dumps rail pressure and stalls. New FPR should resolve?
Am I on the right track?
1) Dad owned truck for 3 years. He removed the factory fuel filter assembly and put a BMP "lift pump" filter housing on it. Never experienced this he says. He towed a ~10k 5th wheel camper. (He also doesn't live near much elevation change.)
2) We got truck a year ago. No issues observed.
3) June, we bought a ~9k 5th wheel camper. I replaced every coolant line, fuel line, and hydraulic line under the hood to solve some weeping fuel lines in the valley. July 4th, took first trip with camper. Headed into the hills on a hot day with AC on max. No issues.
4) Got home, changed fuel filter as PM.
5) Very next trip. Arrived at campground. Backed into spot. Unhooked camper. 15 minutes later, restart, truck cranks, runs for a few seconds, and stalls before I can put it into gear. I figured residual air in the filter. Lift pump was running. I purged from test port and got it to start.
6) Came home, did the same thing after we unloaded. (Probably 90 minutes of heat soak time.)
7) Subsequent camping trips, same thing on hot restarts. Starts, runs for a few seconds, and stalls before I can put it into gear. Eventually it will restart. Sometimes right away. Sometimes after a few tries.
Casual observation is that I didn't get the new fuel filter on right, and it's sucking in air. Read on.
Additional info:
- Never does it unless camper is involved. This summer it was like clockwork.
- I did errands and did short trips when it was still summer (hot out), and could not duplicate. No stalling and steady rail pressure at idle. Only after towing.
- It's not my daily driver. I can hot park the truck for a week and it'll crank right up. (Leads me to believe this is not a prime issue.)
- Before/during/after the hot stall, I notice engine tone will oscillate, observable on rail pressure readout on scangauge if I look fast enough. Once driven a bit, oscillation goes away.
- Late fall trips (not as hot) it hasn't stalled on hot restarts. Instead, I might observe the rail pressure oscillation but engine will manage to stay alive and get past it. Stab the throttle or drive it a bit, oscillation goes away.
- We can hit the hills and get it hot. If I let it idle while unhitching and let it sit overnight (complete cool off) it'll crank and idle smooth.
My theory is that the fuel pressure regulator is in the earliest stages of going bad. It takes lots of heat in the CP3 to cause it to act up. When hot, the plunger doesn't move easily and causes the typical oscillation of a bad CP3 FPR. Somehow it's fine when running, but shut it off and restart, it oscillates and hangs so bad it dumps rail pressure and stalls. New FPR should resolve?
Am I on the right track?
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