Fuel delivery issues

[nm9stheham]

So is the one that is connected... connected to a vent line going up front? If so, where does it terminate up front? That would be adequate, but I would put a little filter on that line to keep dust, etc., out of the tank.

 

[Dave Haertel]

So is the one that is connected... connected to a vent line going up front? If so, where does it terminate up front? That would be adequate, but I would put a little filter on that line to keep dust, etc., out of the tank.

I'm not sure, I never followed it, it may have gone straight up to the separator. I think it's probably safer to just cap them all and then use a vented cap, since the can is gone as is the separator.

 

[TrailBeast]

Thanks, this sending only has a supply, no return line on it. The pump itself has two different types for inlet and outlet. The outlet (going to the carb) is a hard line threaded that gets connected to rubber line to go to the carb, so those connections are correct as they can only go one way.

I think I’m going to pull the hard line off, make sure nothing is blocking that off somehow going to the carb. Then I’ll look at the supply line to see if there’s a crack or break somewhere stopping it from creating suction. So frustrating that it was working before I swapped this out.

What I like to do when I question weather the fuel is capable of being picked up is to take the inlet line off the pump and blow in the line until I hear bubbles.
No bubbles= no fuel available to be picked up.

BTW, mechanical pumps never need primed, so if 1-2 shots in the carb doesn't make it get fuel something else is wrong.

 

[Dave Haertel]

What I like to do when I question weather the fuel is capable of being picked up is to take the inlet line off the pump and blow in the line until I hear bubbles.
No bubbles= no fuel available to be picked up.

BTW, mechanical pumps never need primed, so if 1-2 shots in the carb doesn't make it get fuel something else is wrong.

I was thinking that also, that it never seemed to take this long. It seemed crazy that it just wasn’t getting fuel since it was never an issue before that.

 

[Dana67Dart]

Just a note... before you go to the trouble and expense of replacing fuel lines,

• disconnect the line at the tank, and at the fuel pump and literally blow into the line. if you can blow air through the line it is not plugged.
• next do the same at the tank, hook up a few feet of tube to the fuel pickup tube to the tank and as someone else already mentioned blow and see if you hear bubbles in the tank. There is a possibility that the pickup is not bent down enough, I saw a Factory service bulletin once for a different car that told mechanics to bend the pickup down as some factory made pickups were not at the correct angle.
• next hook up a short piece of fuel line to the inlet of the fuel pump and submerge it is a can of gas, prime the carb and see if the pump will pull fuel from can and feed carb once you get it running.
• next be sure fuel lines and filter are free to flow by disconnecting both ends and blowing
• check the floats and needle seat is free to move, attach piece of fuel line to carb, be sure the float bowl is empty and blow into it, if you can, the needle is not stuck to its seat

ON A SIDE NOTE... are you sure you have the right fuel pump, the wrong one might not be hitting the eccentric.

Any chance the eccentric is no longer in place?

 

[Dave Haertel]

Just a note... before you go to the trouble and expense of replacing fuel lines,

• disconnect the line at the tank, and at the fuel pump and literally blow into the line. if you can blow air through the line it is not plugged.
• next do the same at the tank, hook up a few feet of tube to the fuel pickup tube to the tank and as someone else already mentioned blow and see if you hear bubbles in the tank. There is a possibility that the pickup is not bent down enough, I saw a Factory service bulletin once for a different car that told mechanics to bend the pickup down as some factory made pickups were not at the correct angle.
• next hook up a short piece of fuel line to the inlet of the fuel pump and submerge it is a can of gas, prime the carb and see if the pump will pull fuel from can and feed carb once you get it running.
• next be sure fuel lines and filter are free to flow by disconnecting both ends and blowing
• check the floats and needle seat is free to move, attach piece of fuel line to carb, be sure the float bowl is empty and blow into it, if you can, the needle is not stuck to its seat

ON A SIDE NOTE... are you sure you have the right fuel pump, the wrong one might not be hitting the eccentric.

Any chance the eccentric is no longer in place?

I guess it's possible the eccentric is out of place but I never turned the car over with the fuel pump out of it so I'm not sure how it would slip. I would think if it was out of sync that the handle would have been mangled on the one I took out or at least marred up, which it wasn't so I'm just not sure on that part.

As for the other items, all good troubleshooting ideas. I plan on getting under the car tomorrow morning and running through all of those ideas. I wish for once I had bought a compressor, I could actually put a good amount of air through the lines then to maybe push out any garbage in there. With only blowing through it with my lungs, doubtful anything is going to move with the exception of some air.

The section from the outlet of the pump to the carb is short enough, I'll just go ahead and replace all that just to be safe.

 

[Dana67Dart]

My point about blowing is that you will be able to tell if the tube has a restriction or not. if not that's not the issue, move to the next.

 

[Dave Haertel]

My point about blowing is that you will be able to tell if the tube has a restriction or not. if not that's not the issue, move to the next.

Oh I understood, I'm just thinking about if it was enough pressure and there was just a simple bit of debris, a compressor could blow it through, where blowing with just my lungs wouldn't get that done but might blow enough through to prove that it's not fully blocked. I'd find other uses for it (a compressor) but I just never pulled the trigger on one.

 

[Dave Haertel]

Just a note... before you go to the trouble and expense of replacing fuel lines,

• disconnect the line at the tank, and at the fuel pump and literally blow into the line. if you can blow air through the line it is not plugged.
• next do the same at the tank, hook up a few feet of tube to the fuel pickup tube to the tank and as someone else already mentioned blow and see if you hear bubbles in the tank. There is a possibility that the pickup is not bent down enough, I saw a Factory service bulletin once for a different car that told mechanics to bend the pickup down as some factory made pickups were not at the correct angle.
• next hook up a short piece of fuel line to the inlet of the fuel pump and submerge it is a can of gas, prime the carb and see if the pump will pull fuel from can and feed carb once you get it running.
• next be sure fuel lines and filter are free to flow by disconnecting both ends and blowing
• check the floats and needle seat is free to move, attach piece of fuel line to carb, be sure the float bowl is empty and blow into it, if you can, the needle is not stuck to its seat

ON A SIDE NOTE... are you sure you have the right fuel pump, the wrong one might not be hitting the eccentric.

Any chance the eccentric is no longer in place?

Ok, so I pulled the line off the inlet side of the fuel pump and blew into it, I felt a lot of back pressure but my wife did hear some noise in the tank, not bubbles but heard some activity when I was blowing into it and smelled fumes. While I was at the end of my breath I tried to stop the pressure by not allowing air to escape but not blowing into it, the pressure slipped away like there was an opening somewhere, not sure if that's a good indicator that something is wrong with the line or those vents that should or shouldn't be hooked up.

Next I dropped a hose into a gas can and connected to the inlet side of the tank and she more or less fired right up, so at this point, my assumption is that the fuel pump and the connecting hoses/filters to the carb are good.

 

[Dave Haertel]

I got called into work until about 5 but after that, I'll be crawling under to look at the lines and the tank. Unfortunately, this uncovered some other issues, the driver's side head seemed to be sizzling hot, not getting coolant my guess, and the brake vacuum somehow got all screwed up because the brake pedal was stuck to the floor and wouldn't budge, so I've got those 2 issues to now deal with also.

 

[Dana67Dart]

The fuel line to the tank should not hold pressure. The tank has many open vents and with the gas cap off an even larger one.
A slight restriction could be you pushing fuel out of the tube and back into the tank.

I would still pull the hose off at the tank and blow into theline at the fuel pump end. There should be basically no restriction once any fuel in the line is blowen out.

You know the fuel pump works and the lines to the carb and carb are working

As a final thing you could hook up a piece of hose to the tank end of the fuel line, put that into a can of gas and see if it runs. Then you have only the sender pickup to be the issue

 

[Dana67Dart]

my assumption is that the fuel pump and the connecting hoses/filters to the carb are good.

Just noticed in your video that your fuel can was higher than the carb. Do the same test but with the can on the ground. The fuel could have been assisted by gravity and you could actually have a bad fuel pump.

 

[Dave Haertel]

Just noticed in your video that your fuel can was higher than the carb. Do the same test but with the can on the ground. The fuel could have been assisted by gravity and you could actually have a bad fuel pump.

Thanks, the can was actually on the ground when I started the car the first time, I just moved it up to try and move the car a little bit, that's when I found the brakes were locked down.

When I get home tonight, I'll pull the line off the sending unit to see if I can blow through the line no trouble. I'm starting to lean toward those additional 4 vent hoses being capped somewhere else in the system, so capping them off would be a priority. I couldn't find any caps for those at the local auto parts store but I've got some others a little further a way that I'll try.

I'm probably going to replace the check valve on the brake booster, as that's fairly cheap and easy enough to replace, hopefully, that'll give me brake pedal back. I'll have to dig around some for the head issue. Not sure why it's only the driver's side that seems to be running hot, probably worth swapping a thermostat and check for leaks.

 

[Dana67Dart]

I'm probably going to replace the check valve on the brake booster

If you are refering to the valve that goes between the vacuum hose and the booster that would not produce the pedal to the floor that you experianced. The external valve only keeps vacuum in the canister. There is some valving inside the booster that must be malfunctioning.

For the moment you could cap off the vacuum to the booster and as long as you brakes work propperly you could temporarilly drive it that way.

. I'm starting to lean toward those additional 4 vent hoses being capped somewhere else in the system, so capping them off would be a priority

As long as you have a vented gas cap, capping them should not be an issue, as well as leaving them un capped for the moment( other than insects and dirt and moisture and fuel vapors)
If you think you are pulling a vacuum in the tank leave the gas cap off while testing

 

[Dave Haertel]

If you are refering to the valve that goes between the vacuum hose and the booster that would not produce the pedal to the floor that you experianced. The external valve only keeps vacuum in the canister. There is some valving inside the booster that must be malfunctioning.

As long as you have a vented gas cap, capping them should not be an issue, as well as leaving them un capped for the moment( other than insects and dirt and moisture and fuel vapors)
If you think you are pulling a vacuum in the tank leave the gas cap off while testing

Ok, I'll leave the cap off for now then. Still stuck at work but hopefully done soon with a little bit of time left to work on it some more tonight. If the booster is shot, it's probably going to be later this week then before I can get a replacement so I can drive it. I also still have to figure out the overheating issue on the driver side. The heads were sizzling and I only ran it for a handful of minutes so there's some serious lack of coolant movement going on there, not sure why but that'll need addressing as well.

 

[Dana67Dart]

Thanks, the can was actually on the ground when I started the car the first time,

Got it. That does prove the pump through carb is good to go.

Your getting closer!

 

[Dave Haertel]

Got it. That does prove the pump through carb is good to go.

Your getting closer!

Yea I felt good about that progress this morning. I'm hardheartedly thinking that maybe since it's primed now that it'll create enough suction to get it through the line. That's probably just wishful thinking though.

 

[Dave Haertel]

Ok, I just finally got back under the car and found the issue. If you look at the image below, that's the section between the sending unit outlet and the first section of steel line. Dry rotted all to hell. Replaced it with brand new hose and she fired right up. Not only that but actually filled the filter more than it was before.

I also somewhat figured out part of the brake issue, the last time the car was moved from the shop that I had help me with the electrical, the tow truck driver applied the parking brake. I never saw it was engaged. I still have a softer than normal pedal but I think that's just lines that need to be bled or the Master Cylinder needs attention.

Serious thanks for everyone who posted assistance on this issue. I'm glad she's running again at least.

fuel-line-section

 

[red67gts]

glad you found where it was sucking air