7.3 spits and spudders
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7.3 spits and spudders
alright my 1992 7.3 none turbo with 181 thousand miles on it is not running right.
sitting at an idle sometimes it will start to buck and run rough. while im driving lets say in third holding the throttle at one spot with out moving it, it will get a kinds of power and accelerate other times it will loose power. sometimes when i take a corner the engine dies like its not getting any fuel. leave it in gear and step on the pedal and it will pick back up and run. this is not how the engine runs period the hole time its on but it does these things on a daily basis. if im lucky i get one day a week were it dosn't act up.
i don't know much but i'm thinking injection pump. any ideas how i can self test injection pump, fuel pump, and anything else that could be causing this without just replacing one thing at a time till it stops?
sitting at an idle sometimes it will start to buck and run rough. while im driving lets say in third holding the throttle at one spot with out moving it, it will get a kinds of power and accelerate other times it will loose power. sometimes when i take a corner the engine dies like its not getting any fuel. leave it in gear and step on the pedal and it will pick back up and run. this is not how the engine runs period the hole time its on but it does these things on a daily basis. if im lucky i get one day a week were it dosn't act up.
i don't know much but i'm thinking injection pump. any ideas how i can self test injection pump, fuel pump, and anything else that could be causing this without just replacing one thing at a time till it stops?
Posting Guru
Joined: Dec 2005
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From: Peterborough, Ontario
Sounds like it's sucking air somewhere, or at least starving for fuel. I would look over the fuel lines to make sure that none are cracked rusted or leaking, make sure you have at least 1/4 tank to eliminate fuel pickup issues.
Other potential areas could be the fuel filter, the filter base, or maybe the lift pump.
Other potential areas could be the fuel filter, the filter base, or maybe the lift pump.
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as far as fuel lines go i inspected them pretty thoughly. couldn't find any wet spots, no leaks to be found. doesn't mean thats not the problem though. got to check the fuel filter but i have changed that before after a regular oil change and it was doing this before the filter change. it does it with a full tank but if the fuel pump was bad would that matter? i got a few more things to check but is there anything else that i can look at with out much tools or knowledge needed?
Fleet Owner
Joined: Jul 2006
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From: Mi'kma'ki
yeah for sure.if the lift pump is no longer supplying enough pressure and flow rate,she can't get enough fuel.
that's the first thing to check.
you also should know,as general rule the ip and injectors are medium ware items,and last around 100k miles at peak performance and fuel economy.so if they're stock anyway,and you plan on driving the truck for much longer.it's something to keep in mind.
TikiWiki : IDI Fuel Injection Servicing
that's the first thing to check.
you also should know,as general rule the ip and injectors are medium ware items,and last around 100k miles at peak performance and fuel economy.so if they're stock anyway,and you plan on driving the truck for much longer.it's something to keep in mind.
TikiWiki : IDI Fuel Injection Servicing
Posting Guru
Joined: Dec 2005
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From: Peterborough, Ontario
Well, when it's running at an idle, you could try depressing the schrader valve and see whether it gives you a clear fuel flow, or if you are getting bubbles.
If you want to check fuel flow (the lift pump) pop the wire off the fuel shutoff solenoid, pull the core out of the schrader, and cranking it should give you about a third to half a pint at 5-7 PSI...dang it..forget the time period for that....someone will come along shortly to post that I'm sure!! I want to say about 10 seconds though?
A common spot for line issues are the cross member where it goes from driver to passenger side, it's steel at that point and tends to rust. It also gets dribbles from the engine at times, so it may be hidden by oil leaks. I think I recall someone saying they had a rubber line from the steel line to the lift pump deteriorate and start to leak as well.
If you want to check fuel flow (the lift pump) pop the wire off the fuel shutoff solenoid, pull the core out of the schrader, and cranking it should give you about a third to half a pint at 5-7 PSI...dang it..forget the time period for that....someone will come along shortly to post that I'm sure!! I want to say about 10 seconds though?
A common spot for line issues are the cross member where it goes from driver to passenger side, it's steel at that point and tends to rust. It also gets dribbles from the engine at times, so it may be hidden by oil leaks. I think I recall someone saying they had a rubber line from the steel line to the lift pump deteriorate and start to leak as well.
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