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Discussion Starter #1 (Edited)
Hi all,

I purchased an old Dodge RV (a TravCo). The former owner put an Isuzu industrial / mechanical 4BD1T in it. On a cross-country ride, it died in Iowa. First, it lost power and couldn't go more than 20 MPH. Then it died and wouldn't restart. Three fuel filters were replaced. The van will now run great for a few hours, and then it suddenly loses power, especially just after going up a hill and starting downhill, dropping from 60MPH down to 35 or less. After a few seconds or so, it kicks back to full power. A few times it died, but I could restart it. I've put various additives in the tank.

Ideas? Does the uphill to downhill change suggest something to do with the fuel tank?

Another thread mentioned a screen on the banjo bolt on the lift pump. Could that cause this?

Many thanks.
Jordan
 

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91 yj
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Absolutely would cause that. Screen in banjo is a must check. Another thing to check would be fuel pickup in tank. And also my water separator is a clear glass thingy with a small filter inside it. That little filter can be plugged as well.
 

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Fuel pressure gauge when your back in action would be a great indicator of what's going on. You can drill and tap the last banjo before the pump or buy a pre tapped one from a place like genos garage website. A simple fuel pressure gauge that reads up to 40psi as most put about 15psi . If your climbing a hill full throttle and pressure dies so does motor or plugging up filters uphill see a drop consistently. Also your mechanical pump could have sticking valves and springs.
 

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Ben, if that engine has the A100 injection pump, the fuel pressure should be in the mid to upper 20's PSI. Same pump came on the Cummins 4bt. You covered 2 very important areas. The pre pump screen in the lift pump can get clogged and shut off the fuel. Also, if there was any kind of filter in the fuel tank, those can also be clogged by diesel. Normally, don't want a filter sock in the fuel tank of a diesel. Your recommendation for a fuel pressure gauge is also good. Ranks up there with the boost and pyro gauges.
 

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I have covered every square inch of my fuel system on my conversion. My biggest problem stemmed from the small filter in my clear water separator that I couldn't even believe was in there. Then I finally got pressure back. I usually am17psi, full power and full boost Around 30psi I can drop it to 5 lbs of fuel pressure.
 
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