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Random Loss of power/ engine chugs to life and slowly dies off

2K views 21 replies 6 participants last post by  sackman9975 
#1 ·
My 1984 351W HO engine will start up heavy, and chug for a while before dying off. revs are way down from when it works (will work sometimes and die out other times). Carb could be dirty, and maybe fuel filter. has fresh tank, gas, and fuel pump, and sending unit. any ideas? I can get it to run if I stay on the gas... but it struggles a bit.
 
#2 ·
Could be a number of things:

Bad wires, dirty fuel filter, timing is off, vacuum leaks, worn cam lobes......just to name a few.

Have you done anything recent to the truck that this may be a result from?
 
#9 ·
hey I own a 92 full size eddie bauer bronco 4x4 with an e4od auto trans and a 351w. I let the truck sit up for a year while I had the trans rebuilt. when I finally got the trans back in the truck would not start. I was finally able to start it with starter fuild. and when I say started I mean it just cranks and cranks but no start the the starter fuild it fires right up. but it sounds rough and with a mis fire. so I changed plugs, wires, distburer cap, rotor, and fuel filter. nothing changed at all sounds the same and it dosent start with out using starter fuild. and also the fuel pump stays on all the time when the key is on. I don't know where to begin or what to replace now. I looked on online but there is nothing specific or with details on where I should start first. and also the truck wont climb hills and it drives great on level ground. when you start to climb a hill ill be driving at 40 mph and when it starts to climb it drops to 10 mph and the truck will not accelerate till on level ground again could this be the fuel pump or what. I cant pull codes either due to the fuel pump always being on either. any help will be useful.
 
#10 ·
...also the fuel pump stays on all the time when the key is on.
Start there. :)

I had 3 fuel relays that were bad but they'd run with the key off too tho. :/
And an EEC relay that'd keep it energized with the key off. I guess it ain't
the relay then? Find out for sure anyway, it won't hurt? ;)

"when you don't know what's wrong, go through it and make everything right"
-Jack Duncan, Tucson Signal Maintainer

You know that fuel pump running like that ain't right, fix it. :)

I watched Jack Duncan fix something that "sorta" pertained to the signal
trouble at hand but mostly seemed like a waste of time, when suddenly
what he was fixing would clear the signals up and the trains would start
running again. :)

Alvin in AZ
 
#13 ·
yes I have a meter. but what do I test the battery or relay or what you weren't really specific. and I can fix anything but iam not really good at figuring out whats really wrong. need to know where to start and what to test. but I need to figure this out before the weekend is over with as this is my daily driver or at least it was.
 
#15 ·
ok besides the pump staying on with the key on what could cause the power lose on a hill. by this I mean when climbing a hill I have no power but on flat ground I have most of the power needed to drive the truck this is my main problem. could it be the fuel pump not sending enough fuel when I hit the gas to climb the hill.
 
#16 ·
ok besides the pump staying on with the key on what could cause the power
lose on a hill. by this I mean when climbing a hill I have no power but on flat
ground I have most of the power needed to drive the truck this is my main
problem. could it be the fuel pump not sending enough fuel when I hit the gas
to climb the hill.
Yeah or the fuel filter or who knows? :)

You aren't supposed to know the answer to the puzzle ahead of time! ;)

You're supposed to use your meter, fuel pressure tester (that you have
or you borrow from a local auto parts chain) and follow Ford's algorithms
to find the problem/s. That's what paid mechanics do right after their 1st
(and maybe 2nd?) guess don't pan out. They hit the books (if they ain't
got it memorized already).

My Bronco was abandoned at a mechanic's shop because the owner
"couldn't" fix it himself, handed it over to a mechanic and then found out
he couldn't pay the bill either. :/

Whatcha gonna do? ;)

I suggest you read the links on Miesk's website and follow the directions
to the appropriate links. Get what tools you need and get with it. You've
got it all-over my-Bronco's-PO, you got the internet and FSB to help you
out. You done got what you need for a first step, -when- you gonna take
that step tho? :)

Alvin in AZ
 
#19 ·
ok I replaced the fuel filter and no change at all. then I got a fuel pressure
gauge and checked pressure at the rail it measured 40 at an idle and when
I hit the gas it drops to no pressure when I let it idle back it goes back to 40
Cool! :)

so what could be the problem.
I don't know what the problem could be. :/

What does Ford's algorithm say to do next? :)

Alvin in AZ
 
#22 ·
You really need to start your own thread and not hijack one that's doesn't even match the stats of yours, plus that's still ongoing. The OP hasn't came back to tell us what his next steps were. You both have two totally different animals.
 
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