Need help - 7.3 PS not running right
#1
Need help - 7.3 PS not running right
Need some help badly with my '02 F350 w/ a 7.3. Here are the symptoms:
Wife was driving the truck about a week ago. Was low on fuel (below 1/4 tank) and she stoppped and got fuel (100% sure it was diesel). About 5 miles down the road truck lost power to where it won't move, engine was knocking loudly, and belching white/blue diesel smoke. Found out truck was low on oil so some was added. No change. Pulled it home (won't move at all under it's own power). I haven't been the best about changing the fuel filter, but tried changing that to no effect. HPOP reservoir is full to within 1" below plug. (guessing HPOP is functioning OK) I can open the fuel bowl drain and turn the ignition on and get LOTS of fuel flowing out of the drain. (guessing fuel pump is OK). Any ideas on what to check next? Here's a little incentive to help - if someone figures this out I will send you a $5 Starbucks gift card (or your favorite coffee shop). I really need this truck to run and right now can't afford to get it towed somewhere to be fixed.
Here's exactly what it does now:
Cranks fine, glow plugs work fine, starts as normal. Runs a little lumpy right after starting. About 10 seconds later the engine starts knocking loudly and the diesel smoke starts billowing out of the exhaust. Throttle pedal has no effect on engine (won't increase RPMs). Will run like this indefinitely, but will not move. Oil pressure ok on gauge.
Truck is in central Iowa if that matters.
Thank you in advance for any/all help. I'll answer diagnostic questions as quickly as I can. I've looked through the archives but haven't seen a truck with these exact symptoms.
Wife was driving the truck about a week ago. Was low on fuel (below 1/4 tank) and she stoppped and got fuel (100% sure it was diesel). About 5 miles down the road truck lost power to where it won't move, engine was knocking loudly, and belching white/blue diesel smoke. Found out truck was low on oil so some was added. No change. Pulled it home (won't move at all under it's own power). I haven't been the best about changing the fuel filter, but tried changing that to no effect. HPOP reservoir is full to within 1" below plug. (guessing HPOP is functioning OK) I can open the fuel bowl drain and turn the ignition on and get LOTS of fuel flowing out of the drain. (guessing fuel pump is OK). Any ideas on what to check next? Here's a little incentive to help - if someone figures this out I will send you a $5 Starbucks gift card (or your favorite coffee shop). I really need this truck to run and right now can't afford to get it towed somewhere to be fixed.
Here's exactly what it does now:
Cranks fine, glow plugs work fine, starts as normal. Runs a little lumpy right after starting. About 10 seconds later the engine starts knocking loudly and the diesel smoke starts billowing out of the exhaust. Throttle pedal has no effect on engine (won't increase RPMs). Will run like this indefinitely, but will not move. Oil pressure ok on gauge.
Truck is in central Iowa if that matters.
Thank you in advance for any/all help. I'll answer diagnostic questions as quickly as I can. I've looked through the archives but haven't seen a truck with these exact symptoms.
#2
Here's a possibility- I'm assuming you have not done the Hutch Mod?
Could be clogged screens in the mixing chamber of the fuel pickup, in tank. Try this (sorry Trey): disconnect fuel line PRE fuel pump. Use a small amount of compressed air to blow back through the line in hopes of dislodging the crap from the screens. Again, low pressure. It shouldn't take much.
Some of the more in-the-know guys will be along I'm sure.
Could be clogged screens in the mixing chamber of the fuel pickup, in tank. Try this (sorry Trey): disconnect fuel line PRE fuel pump. Use a small amount of compressed air to blow back through the line in hopes of dislodging the crap from the screens. Again, low pressure. It shouldn't take much.
Some of the more in-the-know guys will be along I'm sure.
#5
Blowing backwards through the fuel inlet before the pump didn't change anything. I'm thinking pump too because if I start the truck it runs kinda ok for about 10 seconds, then starts knocking and shaking and smoking like crazy. I can hear the pump running down on the frame rail (I replaced it with a Bosch OEM pump about 4 years ago. I have a really bad habit of running the truck below 1/4 tank of gas in it. When I pulled off the inlet just now it doesn't run fuel out - gauge is about 1/4. Sound right? Guess I'm off to get a pump... Suggestions of a reasonably priced one? I'm going to first add a schrader valve to it tomorrow to rule out anything else. Hopefully I can find something that will work locally instead of waiting for something from Diesel O-rings website.
Last edited by ScottInIowa; 11-06-2013 at 07:10 PM. Reason: clarification
#6
It really seems like your pump is just fine, if you're cycling the key and fuel is running everywhere. The OEM pump is pretty reliable... Some never go bad. To have 2 fail in a 4 year period is very bad luck.
I'd bet the farm that you need the Hutch Mod done, especially considering you just said you have 1/4th of a tank at this exact moment. That is prime danger zone for a truck without the mod done. I'd also bet that this COULDVE been your problem last go round.
Do this before spending $100+ on a third pump:
Welcome to guzzle's In-tank Hutch Mod Web Page
I'd bet the farm that you need the Hutch Mod done, especially considering you just said you have 1/4th of a tank at this exact moment. That is prime danger zone for a truck without the mod done. I'd also bet that this COULDVE been your problem last go round.
Do this before spending $100+ on a third pump:
Welcome to guzzle's In-tank Hutch Mod Web Page
#7
Let me rephrase. Your problem is most likely the pickup foot in your fuel tank. The very bottom piece of the fuel pickup assembly. They're prone to falling off completely, which leaves a gap between the line it attaches to and the bottom of the tank. You'll notice it around 1/4 of a tank.
Try putting some diesel in it, maybe you can get the level past the line and get fuel to the pump again. When you disconnect the pump inlet line, fuel should run out constantly regardless of whether the key is on, or whatever. You aren't getting fuel from the tank.
Try putting some diesel in it, maybe you can get the level past the line and get fuel to the pump again. When you disconnect the pump inlet line, fuel should run out constantly regardless of whether the key is on, or whatever. You aren't getting fuel from the tank.
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#10
OP- Was this problem solved?
#11
#14
Went back and reviewed the receipt - definitely diesel. FINALLY was able to get a schrader valve into the fuel bowl just now. 15-20 psi in the bowl with the truck off and the fuel pump on. Looks like a toasted pump for sure. Yes, my truck looks/sounds EXACTLY like the video posted. I think if this was a 'needs the Hutch mod' problem I either would have no flow, or it would be ok on pressure with the engine off, but would drop with the engine running (restricted flow, but can still build pressure). New pump being installed on Monday and will report back then. Thanks all!
#15
Went back and reviewed the receipt - definitely diesel. FINALLY was able to get a schrader valve into the fuel bowl just now. 15-20 psi in the bowl with the truck off and the fuel pump on. Looks like a toasted pump for sure. Yes, my truck looks/sounds EXACTLY like the video posted. I think if this was a 'needs the Hutch mod' problem I either would have no flow, or it would be ok on pressure with the engine off, but would drop with the engine running (restricted flow, but can still build pressure). New pump being installed on Monday and will report back then. Thanks all!