Electric fuel pump

[jgreg53]

My mechanical fuel pump stopped working. I wasn't getting fuel to the carb. Ordered an electric pump. New pump is working. Looking down the throat of the carb I see gas squirting. Car doesn't want to run. It sputters and backfires through the carb. I tries changing the fuel and air mixture, adjusting the float height,  moving the timing a little.  It was running OK before the mechanical pump failed.

Edited August 27, 2023 by jgreg53

[maok]

Try turning your distributor clockwise more.

[jgreg53]

 I moved it counterclockwise a little. I will try clockwise. 

[Sam Buchanan]

If your car was running fine when the mechanical pump quit, it should run fine with no adjustments on the electric pump.....remove one pump, install the other. The carb shouldn't be able to tell how the fuel is getting delivered from the tank. The only way the electric pump could malfunction is if it is delivering fuel at a high enough pressure to over power the needle valve. If fuel isn't overflowing the carb bowl, pump pressure is probably fine.

 

Something else has changed, unfortunately you have changed so many things now that troubleshooting has been complicated. I suggest you put everything back to book specs....float level per spec, timing per spec, and suggested idle mixture per the recommendation in the manual. Only after you have a solid baseline can you start diagnostics.....but most likely your flattie will be happy once you do all the above. 

 

But you did say one thing that might be concerning; "Looking down the throat of the carb I see gas squirting." Do you mean gas squirting without moving the throttle with the pump running or do you mean when the accelerator pump shoots a stream? Please clarify, this could be a major issue if the pump is pushing fuel past the needle.

Edited August 28, 2023 by Sam Buchanan

[Matt Wilson]

The first thought that came to mind was that the electric pump is supplying fuel under too much pressure (as mentioned above by Sam).  That is not uncommon when switching from a mechanical to an electric fuel pump.  I suggest connecting a fuel pressure gage to the fuel line just before the carburetor.  I don't recall exactly what the pressure is supposed to be, but I think it's about 3 - 5 psi.  If it's much more than that, then you'll need to install a fuel pressure regulator in the line. And as mentioned, you'll need to reset all the adjustments to where they were before.

[jgreg53]

Sam. I mean gas squirts when I move the throttle.

[Sam Buchanan]

40 minutes ago, jgreg53 said:

Sam. I mean gas squirts when I move the throttle.

 

Ok, that's fine. Consider the suggestions offered above and get back with us. 

[Doug&Deb]

Which electric pump are you using?

[jgreg53]

OK. I took the line off the carb. Turned on thr pump. Nothing. I pulled the out line from the pump. Turned it on. Nothing. Clamped the line going to the pump and pulled it off. Loosened the clamp and lo and behold no gas came out the line.  Shoved the air hose in the line and blew. Nothing. Blew some more. Gas came gushing out. Put the lines back together and she started. Had to reset the float. Drove from the garage to the front of the house she died again. Pulled the line from the carb. Pump is spitting a little gas. Not enough to keep running. This is a replacement tank from tanks inc.

Edited August 29, 2023 by jgreg53

[Sam Buchanan]

How is your tank vented? Is it via the cap? (probably is) What happens if you leave the cap off after you get it running? Does it continue to run?

 

The vents in the cap are very small openings, they may be corroded and blocked. Here is an opening inside the filler neck.

 

 

 

And this is an opening outside the neck. These passages must be clear in order for the tank to vent and allow gas to flow to the carb.

 

 

 

 

 

Here is a backup vent I drilled in the filler neck when I was troubleshooting fuel flow on my P15. I ended up replacing the ENTIRE fuel system and it has been flawless for the past three years. I still have the drilled hole in the neck since I'm using the original cap.

 

 

[jgreg53]

Interesting. Why do you suppose it hasn't been a problem until now? My tank has a vent out the top with a hose going to a vent contraption that I located inside the fender.

Edited August 29, 2023 by jgreg53

[DonaldSmith]

I've often wondered about the function of the bypass line in the filler pipe.  I remember my dad's Suburban, which like mine today, whistled during fill-up.  As the tank got full, the whistling stopped.   Ahah!  Maybe that's it.  When it stops whistling, the gas is up to the filler pipe, so stop pumping. 

 

This bypass line, or whatever they called it, did not vent the tank. It may have helped during the filling process. 

 

 

[Sam Buchanan]

11 hours ago, jgreg53 said:

Interesting. Why do you suppose it hasn't been a problem until now? My tank has a vent out the top with a hose going to a vent contraption that I located inside the fender.

 

Ok, sounds like you have a non-stock tank/vent installation. You can ignore what I suggested provided you are positive the tank is venting properly. What is a "vent contraption"?  ?

 

If fuel isn't getting to the carb there just aren't many reasons why that would be occurring, the fuel system is extremely simple. Just start at the tank and positively verify all is as it should be as you work your way to the carb.

Edited August 29, 2023 by Sam Buchanan

[Dave72dt]

!2 v pump on a 6 v system?   Even a 12v on a 12 can be polarity sensitive.  Where is the [pump located?  Will it pump if you take the fill cap off?  Where does the fuel line come out of the tank?  Top or bottom?

[jgreg53]

The contraption is a round metal piece that goes on the end of the vent tube. I took lines off all the way to the  tank. Nothing was coming from the tank. I bought 5 gallons of gas for the tank. Keep in mind my fuel gage is reading 3 forth full this whole time. I put the gas in.  Tried to start it and nothing.  I took the line before the pump and nothing came out shoved the air hose in the line and I got sprayed with gas. She started after about 3 minutes of cranking. I still need to set some things back to where they were before all this started. Thanks for your help guys.

Edited August 29, 2023 by jgreg53

[Los_Control]

Just now, jgreg53 said:

I took lines off all the way to the  tank. Nothing was coming from the tank.

Common sense says the problem is in the tank?

If you take the gas cap off & tank still does not gravity drain on the ground .... the tank is plugged.

 

Couple reasons why this can happen ..... question is, how old is the tank?

If it is original do you just want to replace it & be done with issues?

Or do you want to pull it & try to clean & restore it?

 

My tank failed because of rust inside. I could run it for awhile then the pickup tube would clog & it would die. .... Let it sit for awhile & it would run fine for awhile til it clogged again. ...... Run it off of a gas can on the bumper it is fine.

 

Possible your mechanical pump is still working? Just run a fuel line from a 2 gallon gas can to the pump & see if it runs.

[jgreg53]

I bought this tank from tanks ink about 5 years ago. I wouldn't think that there would be anything wrong with it.

[Los_Control]

Ouch! .... I also have a Tanks tank that is not installed yet .... I'm pretty happy with the quality of the tank but still welding so not installed yet.

 

I wonder what would be involved in using air to blow the tank out? .... I still think it is clogged somewhere, but you are now stuck unclogging it.

 

Couple months ago I took off the temp fuel line from my temp gas tank to the fuel pump. There was a large bug that was clogging the fuel pump.

It got into my temp tank, sucked through the rubber fuel line .... just too big to get into the fuel pump. ..... These things happen.

 

I remember years ago hearing multiple issues about bad fuel delivered to the gas stations.

I'm not suggesting you did anything wrong .... just saying it happens. I remember fighting a fuel issue for almost a year before I realized it had water in the tank .... This came from the gas station. ....... Did the gas station get a big flying dragon in its tanks that then pumped it into yours? ..... I have no idea.

 

I hate to say it, I think you need to pull your tank & see if you can figure it out where it is plugged.

My Tanks has a drain plug on the bottom .... that should work .... I would be really interested in what the gas looks like after it is poured out & settled in a bucket.

Maybe run it through a filter to see if anything is caught. Look for water in it .... Water will look like a big air bubble in the bottom of a bucket .... it is heavier then gas & collect together. ..... Not your problem but would still be looking for it.

 

My Tanks has two covers on top, 1 for fuel sender & 1 for a aftermarket electric fuel pump .... you should have some decent access to the inside.

 

You disconnect the fuel line from the tank, you have fuel in it .... it's not draining .... the problem is in the tank.

[Los_Control]

Just a thought .... I wonder how far a guy could run some wire through the fuel port of the tank?  

There should be a filter sock on the bottom of the pickup tube .... I'm guessing ... still may be able to run a probe wire into the tank ..... I dunno .... if there was a filter sock the tube should not be clogged?

Snake it out like a plumber does with drains may be a option to think about.

[jgreg53]

She's running now . Going to see where it goes from here. Having to pull the tank is not something I want to do.

[Jerry Roberts]

12 hours ago, Los_Control said:

Just a thought .... I wonder how far a guy could run some wire through the fuel port of the tank?  

There should be a filter sock on the bottom of the pickup tube .... I'm guessing ... still may be able to run a probe wire into the tank ..... I dunno .... if there was a filter sock the tube should not be clogged?

Snake it out like a plumber does with drains may be a option to think about.

An old choke cable in a drill will work as an auger . Watch out for sparks . 

[maok]

Before you blow yourself up, is there any rust blocking the fuel filter?

 

An electric fuel pump needs to be plumbed near the tank and at the bottom level or lower than the tank.

[Sam Buchanan]

14 hours ago, jgreg53 said:

She's running now . Going to see where it goes from here. Having to pull the tank is not something I want to do.

 

So.......was it just out of gas??

[jgreg53]

After I added gas, nothing was coming out of the fuel line until I blew air up the line. The line connects on the tank about halfway.  I'm assuming that inside the tank there's a hose or something that lies in the bottom of the  tank. 

Edited August 30, 2023 by jgreg53

[Sam Buchanan]

The aftermarket tank in my car just has a metal tube extending from the tank fitting to the bottom of the tank, no filter or sock. Probably a good idea for those of us with these tanks to drain (flush?) it every year or so to remove any particulate that might accumulate.