Fuel Pump?

[Mayhem]

Ever had a mechanical fuel pump go bad and dump pieces of the diaphragm into the fuel line and catch in the filter?

I apparently experienced this today. Fuel pump started failing and falling on its face. Noticed glass filter was almost running dry at times. Made it to auto parts store and got new one, limped it home, replaced it.

Fuel pressure is now back to 9 psi, but engine started falling on its face again and not wanting to idle. Clear glass filter is full.

Upon getting it home again and looking, filter is full of little brown and black chunks of junk. I am extremely hoping it is just diaphragm fragments and not crap in the fuel.

It acted like it was running rich and almost flooding, not wanting to idle, but fuel pressure was holding good. Even smoked at idle at a red light like it was rich.

Waiting for it to cool off now. Am going to remove and replace new filter, and then run some fuel from line into a jug and make sure all is through the lines before reconnecting.

Thoughts?

[PxTx]

Could have a little dirt in the needle/seat vale on the carb if it was acting rich. Post what you find. May want to consider going with an electric fuel pump. If you have one already and push through the mechanical, that could be what caused the diaphragm to fail. If the diaphragm failed, what stops fuel from leaking into your crank case? Change your oil too.

[69 Post Sedan]

^^^^What Paul said.....go through the carb. I would get rid of the clear fuel filter also. I have heard nothing but bad things with the glass breaking and causing a fire!

Kurt

[Mayhem]

All good thoughts.
I wanted to convert to an electric, but funding is short right now after the holidays. I replaced with a new mechanical one.

I have never heard of a glass filter breaking. At least not on its own. It is suspended to where it can't hit anything, without a major impact anyway.

Still don't want a fire in an impact either though. That leaves the cheesy plastic "kind of clear" ones. I always liked being able to really see what was in there.

I am putting one before and after the pump to rule out dirty gas or anything coming from the tank. This actually started right after I filled up with some pump premium.

Will let ya know. Thanks guys.

[njsteve]

Sadly, I think the diaphragm going bad is a symptom of ethanol added to modern gasolines. It attacks the old rubber components that aren't made to interact with modern fuels.

[Mayhem]

No doubt. I don't know how old it was either. So are the same components used in an electric pump? Could it have the same rubber failure of an impeller or diaphragm?

[Tommy]

Changing the oil is a good idea. I had a Vette years ago that had a bad diaphram and leaked fuel into the crankcase. How old is your fuel tank? Is it the original? I don't like the glass filter either and personally I would stay with a good mechanical pump.


Tommy <<GRAEMLIN_URL>>/3gears.gif

[Mayhem]

New mechanical pump, 2 new plastic clear filters between the tank and pump, one glass (well isolated from everything) just before the carb.

We dropped the tank, drained it completely, filtered the fuel through old T-shirts into 5 gallon fuel jugs, and kept sloshing and rinsing the tank with clean fuel.

We kept getting green soft material in little chunks/pieces the size of sawdust or wood shavings. I can only describe the color is that of neoprene gloves-kind of a bright deep green.

After multiple rinses it looks like most if it is out. The tank looked great, like new, as does the whole underside of the car.
We put it all back together, went and filled it the rest of the way with premium (the only performance shop with fuel is closed until Tuesday!!!)

It seems to be better, but the filters don't seem to want to fill up much. The plastic one is less than half full, and the glass was almost empty when I pulled in and opened the hood, Once I let it idle it filled back up, but the plastic one just before the pump won't get past half full.

We blew out the cool-can, the entire line back to the tank while it was off, the sending unit and sock filter looked fine.
The only possibility left would be something in the carb, but I cannot imagine how anything would get past the filter, and I REALLY don't have the knowledge or care to tear into a brand new carb.

The oil looks and smells fine, and the old fuel pump arm didn't have any signs of fuel smell. I have the stuff on hand to change the oil, but likely won't get to it today.

I'm gonna get cleaned up and drive it to our Saturday night meet and see how it does.

[PxTx]

First off, some of the old electric fuel pumps do not like the modern fuel. The Holley Blue seems to work just as well tody as it did back in the day.

Big question is do you run a return line or not? The Holley Blue can suffer from running too hot due to &quot;dead head&quot; when the regulator sees the carb has enough pressure to the needle valve. A return line is a better design, but I've been running a Holley Blue and regulaor w/o a return line for 20 years.

I've not know a car that didn't improve the ET when a mechnical fuel pump is replaced with an adequate electric pump and complimenting fuel system (lines, reg, etc).

As for the Glass Filter. I really like them. Against the advice of wise people (#1 my Pop) I kept one on my wife's car. I like being able to see the fuel. Motion sold them, so they couldn't be bad, right?

I've probably typed the story before, but basically we were driving in the Duster and hauling up the mountains around Penn State. Started to smell gas, then SAW gas running in the car. Pulled over quickly and poped the hood. Gas was spraying everywhere!

The fuel was spraying out from between the glass and the metal end caps. It then would bounce off different parts and the mechanical engine fan really blew things around. Gap, plug wires, all soaked in gasoline!

I walked about a mile to a station and got some things to rig up a safe fix. Saved the fuel filter and found it could be tightened up, but stayed away from the poor design for ever.

I know you might not want to mess with the HP carb you just bought, but it might be worth checking the bowls and also making sure there is no dirt pinched between the needle valve.

[Mayhem]

Hey Paul, I was waiting for a response from you. <<GRAEMLIN_URL>>/grin.gif

Nope, no return line. Just the single 3/8 feed line. Now, coming from the tank on the passenger side, next to the feed line, there is a second line that disappears under the car somewhere, and there is a line connecting to the charcoal (?) vacuum canister at the front of the engine bay. I assume it is the same line.

There are also 2 more lines connected to 2 more ports on the same side of the tank but don't have clamps, and running to unknown locations, and also 2 more old lines (not connected to the tank any more) going up into the trunk body area from the drivers side of the tank that don't have clamps, so I assume they are vents or breathers, but there is no canister apparatus in the trunk, and I have no idea where they end up.

This is getting confusing, and I keep editing here- in total there is a feed line, a vent/canister line to the front, 2 more unknown lines that are connected near the feed and canister lines, but they don't have clamps, and 2 old lines on the other side no longer in use, with only one capped port on that side of the tank. WHY on Earth would there be 6 lines???

This car ran great until yesterday when the issue began. We have gone through the entire fuel system at this point. There are a couple of sections of fuel hose, and I replaced them with new fuel line and hose clamps, to rule out dry rotted line sucking air (which is really the best way to describe the symptom.

Under any driving condition, both filters would eventually run almost dry. Obviously it would occur faster when getting on it. Now I did just change a section of hose I missed earlier, and put a new piece on the canister portion under the hood, and went ahead and clamped it since it fit a little loose.

ON a test run I just took, it seemed to not run the filters dry, and even made a hard run through the gears with no muss this time. But it still drops from it's usual 9 psi down to anywhere between 3-6 at times, not just when getting on it either. ** (This is also just a POS standard mechanical pump used in an emergency situation at the time.)

I can't explain why it worked fine before and has these problems now, and I can't imagine anything getting past the filter element into the carb.

I am definitely going to get a nice MagnaFlow electric pump/filter assembly as soon as funding allows. I would have to think that pumping fuel from the rear is much better than trying to suck it all the way from the front.

Any thoughts on the possibility of running a new hard line the whole length to do away with the hose sections? It seems there is going to be at least one section in there coming from the tank sending unit to the pump.

Any thoughts or help would be great.

Thanks everyone, and all your input is very welcome and used. Once I get through this issue, I will do away with the glass filter. But for now it is valuable for debris confirmation.

Here is a drawing to either help clarify, or totally confuse you. <<GRAEMLIN_URL>>/grin.gif

http://blueicehouse.com/n5ssi/Tank.JPG

[PxTx]

Well, the return line comment is more for when you go electric. The fuel staving problem is probably your effort to prevent those green fragments from getting into your fuel pump.

I would not have any filter between the fuel tank and your pump- be it electric or mechanical. A pump typically does much better at pushing. A filter before it is a restriction. Your air bubble in the filter before the pump is trapped air. The filter will not fill up until tha air can purge out. That air bubble is also a restriction.

When the time comes for the electric fuel pump, I would encourage you to run a lare, 1/2&quot; aluminum line as the main feed. You can use the old 3/8th as the return line from a nice regulator. The important part is that the new line has a good pickup so it doesn't suck air. The pump is designed to push, and will have a flame arrestor screen that will be adequte to keep any debris large enought odamadge the pump out. Put a filter on the push side of the pump to protect your carb. I know there are two schools of thought on where to place the filter, but I beleive they do more harm that good when placed before a pump.

[TDW]

I've never seen one of the glass filters be &quot;full&quot; of fuel. Be it in a car or on a motorcycle, they always look like they are half full. Maybe you are chasing a problem that doesn't exist? Like someone else said, I would pull the bowls and see if there is any trash in the needle and seat.

[Mayhem]

The glass filter is almost always full or above 75% anyway. The extra filter before the pump was to rule out anything coming from the tank.

So far, nothing has been found actually coming through the line. The green crap was found while the tank was off and the fuel strained.

We have concluded this must have come from the tank of the gas station where I gassed up when all this started.

I am going to replace the glass filter with the new plastic one, between the pump and carb.

Paul, your info on the 1/2&quot; line for an electric is useful and will be put to use when I can order the setup I want.

This car is somewhere around 450 HP right now, and I just don't think a stock mechanical pump is adequate.
I know they have high flow mechanicals, but I honestly prefer the consistent volume of the electric, and the control of the regulator to maintain the suggested psi the carb wants.

Heading out to change the filters around as stated, and then change the oil. The needle/seat advise has been ruled out as it would run great for 15-20 minutes before faltering.

It is definitely a fuel delivery issue in the line. Hopefully, as Paul said, removing the extra filter will help. It ran great last night on a test run. Thanks.

[Mayhem]

Paul- (PXTX)

or anyone who cares to jump in as well,

there is only the 3/8&quot; port on the fuel tank. When I add an electric pump, will it be 3/8&quot; hose to the pump, and then 1/2&quot; coming out of it, or can I replace the sending unit with one with a 1/2&quot; line?

It would be nice to run braided line or hard line, but it seems there is going to be at least a very short hose jumper from the tank to the pump.

Is there another way? I know on my Camaro it was all braided line, but it was coming from a fuel cell, not a stock tank.

[69 Post Sedan]

I personally see no reason to change from a mechanical fuel pump to electric on a 450HP motor as long as you are running a good pump.

My motor, for example, is around 450HP and I shift at 7000 RPM's with no issues and I am running a edelbrock mechanical pump with a 3/8&quot; fuel line.

Kurt <<GRAEMLIN_URL>>/beers.gif

[PxTx]

Kurt, great example. I was in the same camp as you. How do you know you wouldn't benefit from an improved fuel system?

I gained .4 in the 1/4 with no other changes on a 350 hp set-up I would have sworn was sound.

[69 Post Sedan]

WOW.....that's significant. Maybe I should hook up the Holley fuel pump that's still bolted to the car just for sh!ts and giggles.

Thanks for the heads up Paul.

Kurt <<GRAEMLIN_URL>>/biggthumpup.gif

[Mayhem]

Finally! All is well again.

I am only running a clear plastic fuel filter-no glass. The new fuel pump is running 10 lbs at idle, which is too high, but will have to ride until payday when I can start working on the electric pump conversion and get a regulator on it.

I also remounted my &quot;Cool-Can&quot; in a better spot and have all new fuel line. As well as an oil change and radiator flush with new coolant.

It's a happy car again, and I am very thankful this chapter is over with. Simple problems that become a 2 1/2 day nightmare.

Thanks for the help guys. I will be quiet (until I start the electric conversion). <<GRAEMLIN_URL>>/whistle.gif