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

[1984BroncoXLT]

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.

[sackman9975]

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?

[1984BroncoXLT]

recently replaced the rusted gas tank that had really dirty fuel, didn't change fuel filter yet. Spark plugs and wires are new. pretty sure i fixed the vacuum leaks...

[sackman9975]

Were the problems present before you did these things?

I would definitely change your filter next.

[Alvin in AZ]

Originally Posted by sackman9975

Have you done anything recent to the truck that this may be a result from?

Man-oh-man is that a good question. :)
That baby should be at the beginning of every "trouble thread".

Alvin in AZ

[1984BroncoXLT]

it ran somewhat rough, but ran better once I replaced parts. then it started getting rough again. but it will randomly run like a champ, and then the next day run like crap. could it be that i had just gotten gas? the place may have had bad gas.

[sackman9975]

Change the fuel filter then report back

[joesolo71]

Sounds like sending unit problem

[the beast]

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.

[Alvin in AZ]

Originally Posted by the beast

...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

[the beast]

all the fuses and relays are good I double checked them all already. and the fuel pump stays on only when the key is on. I think it may be a fuel pump but I want to be sure before wasting money on something that isnt broke.

[Alvin in AZ]

Originally Posted by the beast

...the fuel pump stays on only when the key is on. I think it may be a fuel pump...

Wow, good shrooms, huh? ;)

Wouldn't it be whatever's energizing the pump at the wrong time be the problem,
instead of the pump itself?

Got a meter? :)

Alvin in AZ

[the beast]

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.

[Alvin in AZ]

Originally Posted by the beast

yes I have a meter.

In that case you got it by the balls but just don't know it yet. ;)

I don't know how to navigate Steve83's website or I'd do it for you.
I give up on that, turned out to be a waste of time. :/

Miesk has got a website with the information on it you need too...
http://www.broncolinks.com/index.php
...it's easier to "run". ;)

Alvin in AZ

[the beast]

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.

[Alvin in AZ]

Originally Posted by the beast

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

[the beast]

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 so what could be the problem.

[BFE1193]

I'd say its one of those terrible VV carbs, those things always have trouble

[Alvin in AZ]

Originally Posted by the beast

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

[Alvin in AZ]

Originally Posted by BFE1193

I'd say its one of those terrible VV carbs, those things always have trouble

LOL :)

BFE, could you be quiet and just pass the molar pulling pliers, please.

Alvin in AZ