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shaking and loss of power

25K views 20 replies 8 participants last post by  Big-diesel21 
#1 ·
1999 F250 7.3 DIESEL WONT REV UP AND WHEN IT DOES IT SHAKES A LOT AND WONT GO PAST 30MPH. SHAKES AT IDLE AND SOMETIMES IT SHUTS OFF. SOMETIMES WHILE DRIVING IT GRABS AND GOES BUT THEN GOES BACK TO MISFIRE OR LACK OF FUEL NOT SURE HOW TO DESCRIBE. I CHECKED FUEL FILTER BOEL TO FIND IT HALF FULL AND THEN WHEN THE IGNITION SWITCH WAS TUNED ON IT STARTED TO BLOW BUBBLE WHILE FILLING THE BOWL UP SLOWLY
 
#2 ·
Sounds to me like you have a bad fuel pump or possibly a clogged up fuel screen in the tank. Do you have a full tank of fuel? Can you hear the fuel pump running when you cycle the key on before starting?
 
#4 ·
Is your check Engine light on. Sounds like you might have issues with injector wiring, but codes would be a good thing to start with.
Could be fuel issues as well.
 
#8 ·
Well I turned ignition switch on and off about ten time letting bowl fill up and then started the truck lots of shaking I shut it down and did a few more switch on and off then started again this time giving it a bit of gas and it stayed on so I let it run for like 5 mins then drove it to gas station filled her up and the rest is history. I believe I have to drop that tank and check cause it all started when I was 1/4 tank low.
 
#9 ·
still no luck

dropped tank today cleaned both filter screens and replaced strainer grill or screen that i found at the bottom of the tank. added 10 gallon of diesel back in it and took it down to auto zone to return somrthing and its doing the same thing. wont go and sound like hell all kinds of valve noise when revving it up and no power just gets up to maybe 40 and then shakes sounds bad when I floor it floor it
 
#11 ·
When you dropped the tank, you should have replaced the quick connects with standard hose and clamps. Those fuel line connectors have o-rings in them that don't seal well under suction. Just disconnecting and reconnecting them will make them leak.
Possibly your fuel pump has gone bad.
 
#12 ·
well that could be a possible one of the fuel lines came off very easy when removing them but i pulled on them when reinstalling them back on to make sure the were secured. not looking forward to dropping the tank again. i was thinking last night the pump is only 19 yrs old wouldn't hurt to replace it.
 
#13 ·
Finally your going to fix the right part. A pressure test from the beginning was what should have been done , and the slow filling bowl should have clued you in a long time ago. Just remember theres air in the system now, and after your pump, its going to run good again, but may cough or stumble over the next 500miles until the air all purges out. Unless your have a regulated return system there is no way to avoid that. Its nothing to worry about and should be expected.
 
#14 ·
Just remember theres air in the system now, and after your pump, its going to run good again, but may cough or stumble over the next 500miles until the air all purges out. Unless your have a regulated return system there is no way to avoid that. Its nothing to worry about and should be expected.
I have to disagree on it taking 500 miles to purge air out of the fuel system. If that were true, every filter change would cause the engine to run like crap for about a week (typical mileage?) The any air in the fuel rail will purge out thru the injectors in a much shorter timeframe, even without a regulated return. The filter in stock form will purge air coming from the tank and pump unless the pump is sucking air continuously.
You're right though that it (air) is nothing to worry about as long as the system is tight.
 
#15 ·
I didn't say it would run like crap, I said it may have some hickups for the first bit until all the air gets out. And yes, every filter change does allow air in. One of the reasons most guy eliminate it. ITs junk. 500 miles is a lot, I agree, but if air gets in, it can take that long to get out. Another reason the return systems were invented, and fixed this issue. Air isn't an issue, I just didn't want the guy making a new post saying it blows white smoke in the morning when he starts it and he thinks its broke. When its just a bit of air in the fuel system. Just a precautionary note so the OP doesn't panic. No need to get your undies in a knot.
 
#16 ·
Ok this morning i removed the shaft inside the filter stand as someone else suggested truck starts a runs fine a little bit of noise and rough here and there. got it on the highway and didnt lack power going uphill but still doesn't feel right. A little jerky when going 65-70 mph but at least is not slowing down to 30-40mph like before. I will gather some cash for the pump. I have been low on money this week. Thanks for all the advise. Let me know if you guys think of anything else I could be missing.
 
#17 ·
give it some time, probably just a bit of air in the system, probably be fine in a couple days of driving. Pump is a good idea still if its been over worked with a plugged screen.
 
#20 ·
This thread is about Superduty trucks which have a different fuel system than your 96.
 
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