E4350 Class C fuel pressure
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Mountain Pass
Joined: Dec 2023
Posts: 163
Likes: 36
From: Tennessee
E4350 Class C fuel pressure
Just finished a long trip out west and fought the issue all the way out and all the way home. This is a 2004 RV, but the chassis says 2003 and the engine has the 2002 return line fuel system. Left with just under 50000 miles and came home with over 54000.
Random misfires, replaced all boots and 1 coil. Ran great for hundreds of miles.
Yes I have a scan tool purchased on the road. Last scans getting home had pending misfires on 4 cylinders, 2 on each bank. This occurred after stopping to fill up and had to get over some very steep hills.
Already have a new fuel filter and just replaced the fuel pressure regulator on the rail.
Zero pressure KOEO, 29 psi at idle, 39 with vacuum line disconnected. Shut engine off and pressure rapidly drops to zero.
Can anyone explain why starting the engine gets me fuel pressure but KOEO does not? I understand the check valve failing when I turn the key off....
Random misfires, replaced all boots and 1 coil. Ran great for hundreds of miles.
Yes I have a scan tool purchased on the road. Last scans getting home had pending misfires on 4 cylinders, 2 on each bank. This occurred after stopping to fill up and had to get over some very steep hills.
Already have a new fuel filter and just replaced the fuel pressure regulator on the rail.
Zero pressure KOEO, 29 psi at idle, 39 with vacuum line disconnected. Shut engine off and pressure rapidly drops to zero.
Can anyone explain why starting the engine gets me fuel pressure but KOEO does not? I understand the check valve failing when I turn the key off....
Thread Starter
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Mountain Pass
Joined: Dec 2023
Posts: 163
Likes: 36
From: Tennessee
Been studying more, seems I have 2 fuel pumps and the switch in the passenger footwell, where I tried to get power door locks to work before we left.....Hmmmm Figured out mega fuse 17 and relay K to check.
Thread Starter
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Mountain Pass
Joined: Dec 2023
Posts: 163
Likes: 36
From: Tennessee
I am dropping the tank soon. I struggled to get pressure to come up and then it would drop instantly on key off. Using AI, and it was wrong, you have to ask it follow up questions, I have one pump in the tank. The second return line is not a return but rather an emissions line. This correlates with having 3 tubes on the pump. No return for the engine but and outlet and return for the generator.
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