Fun video for you to watch....help!

[bradford]

Its not so fun for me.
I am lost.

Situation: 350 block, 307 heads (previous owner), 4 speed manual 4x4.

My truck has been running like crap, so one at a time, I have been swapping parts. I like new shiny stuff so I don't really mind too much but its getting annoying when it doesn't work.
The truck was way underpowered and when accelerating in third gear going to fourth (not floored), it would act like it was running out of gas ....chug jump chug....
No problem, changed the fuel filter. No good. changed fuel pump because I noticed the filter wasn't filling up at all and it was just spitting randomly into the filter.
After changing the pump, I instantly noticed a change. Not so weak, acceleration picked up. But while fiddling with the old Holley that was on it, I noticed it was leaking gas from all over the place when it wasn't running. No problem. I was going to change it out any way.

So, new fuel pump, new 600 cfm edelbrock and it runs alot better. I have had 2 instances where it bogs down like it has no gas. I do believe my distributor is bad too because when I changed out the carb, I changed the vacuum lines as well and the noticed the vacuum advance was loose on the distributor.
That and it doesn't want to start sometimes like its flooding out.

So, I have 2 questions.
1: why the hell is the fuel filter not filling up and spitting gas randomly? 1.1: Is that normal?

2: would a bad distributor make it act like it was running out of gas?

I am just about ready to start riding the motorcycle everyday and give up on this motor and save my money for a new one.
I've replaced just about every gasket I can on it to stop the oil leaks, changed the exhaust, headers, and talked to it at night and told it it was a good engine and it still wont perform the normal duties of a reliable engine!
On top of all that, it still gets 8-9 MPG!!!!!!!!! This cannot be normal!

YouTube -...

[J Knight]

Theres nothing wrong with your motor you have a fuel delivery problem, like a kinked line or a pin hole or a loose clamp thats sucking air somewhere between the tank and the pump.

[bradford]

OK so its a single tank truck.
Now, I dont know how the return line and fuel line thing works.
The fuel pump I have only has one line hooked to it.
The only reference I have to look at is the LMC catalog.
http://www.lmctruck.com/icatalog/cc/full.aspx?page=134
Is my fuel pump supposed to have two connections to it?

[76stepsidechevy]

What the third vacuum hose on that carb hooked up to? I see vacuum advance and pcv whats the one all the way to the right?

[bradford]

Originally Posted by 76stepsidechevy

What the third vacuum hose on that carb hooked up to? I see vacuum advance and pcv whats the one all the way to the right?

That is going to the vacuum ball at the A/C thing I pointed the camera at.
Its a manifold vacuum port.

[bradford]

Anymore ideas on this?

[J Knight]

Typically you should have two lines on the fuel pump and there are 3 lines to your tank.
Big diameter line is your vapor line that goes to your vapor canister. (charcoal)
Medium diameter line is your fuel line.
Small diameter line is your fuel return line, it returnes excess fuel back to the tank.

[bradford]

Originally Posted by J Knight

Typically you should have two lines on the fuel pump and there are 3 lines to your tank.
Big diameter line is your vapor line that goes to your vapor canister. (charcoal)
Medium diameter line is your fuel line.
Small diameter line is your fuel return line, it returnes excess fuel back to the tank.

Oh jeez.
Here we go.
The joys of buying someone elses project stikes again.
Im pretty sure I have no vapor canister. I will get a new pump too. Im glad it was only 18 bucks but it took a while to install cleaning old gasket crud.
Even the old pump had the second line plugged off. I wonder why.
Does it need to have the return line?
Can this cause problems?

[J Knight]

Hang on dont change the pump yet, If the pump only has one line its ok, just make sure its hooked up to the medium size diameter line from the fuel tank.

[J Knight]

Also dont cap of the other two lines (big line & small line) because the tank needs to vent if you dont have a venting gas cap.

[bradford]

Originally Posted by J Knight

Hang on dont change the pump yet, If the pump only has one line its ok, just make sure its hooked up to the medium size diameter line from the fuel tank.

OK.
I bet it is though since the hose that connected to the fuel pump was the same size.
The reason I got this fuel pump was because the motor (bottom end) is from a 72 camaro by the numbers on the block.
So, I ordered a pump for the camaro just to avoid some kind of fitment issue.

[Your41Plague12]

If it sputters under load, check the advance weights in the distributor. Take off the cap and there's little blade-like weights inside. Sometimes they seize up or even rust together if the truck (or just the distributor) sat for a while. If you have the cash, a new distributor can never hurt. If not, just use some kind of penetrating oil or lubricant and make sure they move freely. The exact same thing happened to me and this solved my problem instantly.

[bradford]

Originally Posted by J Knight

Also dont cap of the other two lines (big line & small line) because the tank needs to vent if you dont have a venting gas cap.

Looking at the sizes on LMC, the fuel line is the larger of the three unless my math is chopped, the vapor line is mid sized and the return is tiny.

[bradford]

Originally Posted by Your41Plague12

If it sputters under load, check the advance weights in the distributor. Take off the cap and there's little blade-like weights inside. Sometimes they seize up or even rust together if the truck (or just the distributor) sat for a while. If you have the cash, a new distributor can never hurt. If not, just use some kind of penetrating oil or lubricant and make sure they move freely. The exact same thing happened to me and this solved my problem instantly.

yeah its crusty and the advance canister just rattles around on it.
Im replacing it as soon as I get paid again. I already dropped a good dime on the carb and other crap.

[bradford]

Originally Posted by J Knight

Also dont cap of the other two lines (big line & small line) because the tank needs to vent if you dont have a venting gas cap.

I will see if they have been capped off or not.
My question is, why would they put a return line if its not needed?
What does it prevent? is there too much pressure at some point and the carb is not using it? would that pressure make it use more gas?
I've never messed with fuel pumps before.

[J Knight]

Im going to go outside and look I may have screwed up.

[J Knight]

My bad, I been sayin it wrong all day, Im going to have to edit all my posts.
Big line FUEL.
Medium line VAPER CANISTER.
Small line FUEL RETURN.

Sorry bout that.

I cant edit old posts.

[bradford]

Originally Posted by J Knight

My bad, I been sayin it wrong all day, Im going to have to edit all my posts.
Big line FUEL.
Medium line VAPER CANISTER.
Small line FUEL RETURN.

Sorry bout that.

I cant edit old posts.

No problem. I'm learning. Thank you.

[rayfinseats]

FYI: My 83 has a Edelbrock 600 carb and 2 lines (in/out) on the fuel pump. My filter is always about 1/2 full when running.

[Robert8096]

You may want to check out the fuel tank, it could be full of junk or rust and clogging up the sending unit sock that is on the pickup tube.

[motornut]

kinda sounds like what i'm kinda dealing with
and yup big is fuel
Holley carb and with mine the dist weights were not working right when i got it, rusted stuck
the vac advance to carb was hooked up wrong,found vac leaks/heat cracked rubber carb plugs
i was working up to doing the fuel pump fri
maybe drop the tank to clean it out
as like you almost floor it and it's like it's outa gas
but seems ok otherwise driving
but now i'm realizing mine sat for quite a while.....years
and i have an unknown cam.....
now i'm wondering what else? ......like you

[CaliDude76]

Originally Posted by bradford

1: why the hell is the fuel filter not filling up and spitting gas randomly? 1.1: Is that normal?

My truck had stalled, and was starving for fuel too... I did a carburator rebuild and everything..

This may sound dumb, but have you checked to see if there's an inline filter between your tank and engine.. meaning a secondary one under your cab, or bed somewhere before the fuel pump?

I say this because that was the case with mine. I ended up going under my truck pulling my hair out wondering, what the heck was the problem, thinking it was a kinked line or something. I seen that fuel filter tucked up under there that the P.O. had to have put. I pulled it out and tried to blow in it.. clogged like heck... put in a new one, and my truck ran tops!

Just a suggestion to ya..