Do mechanical fuel pump's just quit?

I jumped in the sedan yesterday and turned the switch and my normally dependable quick firing engine just kept spinning,,

Lifted the hood and removed the breather and had my wife spin the engine while I worked the throttle linkage,,,nothing.

I disconnected the line going to the carburetor and tried again,,no gas.

Took the line off the fuel pump,,nothing

Checked the filter leading to the fuel pump and it's clean,,blew air in the fuel line and the line was clear,,and yeah the tank is almost full.

So, I'm thinking the fuel pump took a crap,,but in all my years I've never had one do that. HRP

 

If the return spring snaps,, yeah they will just quit.

 

They are more likely to die when the engine is running.

I've had several give up with no notice.

 

No WONDER we didn't see you at the swap!

Must've been the day to have gremlins- Brad threw the belt on the Corvair wagon coming off of 85

 

They will go out just like that but best thing to do is pull the pump and check it.At least it quit a home and not 40 miles out in the middle of nowhere.

 

You've never had to replace a mechanical fuel pump? They are pretty reliable but like anything mechanical they will break.

Probably a cracked diaphragm.

 

Honestly,,never. HRP

 

Yes they go bad, most likely the diaphragm. But could be broken linage, or bad check valves. They had to be replaced a lot back in the day. They will let gas into the oil before they quit altogether.

 

Everything breaks sooner or later. Most of the crap most parts stores sells now goes sooner rather than later.

 

Mine have always been when the diaphram rips, like if it sits to long with use.

 

If the valve that pumps to the carb get a piece of crud in it,no fuel. had this happen once. And another time the valve assembly fell out.If the pump can be disassembled,do it and take a look.

 

The mechanical pump died on my Studebaker engine and I was able to get a rebuild kit and fixed it myself. There ain't nothin' to them. A diaphragm and 2 check valves.

Of course I F'd it up by trying to drive the pivot pin out and broke the aluminum body. The first one I ever did and nothing is easy for me. Bad eyes contributed to the problem.

 

I would have thought it would have lit off for a few seconds with the fuel in the bowl and the accelerator pump ?

 

one thing for certain, if it is an old part, say 20 years old the replacement will only last a few years.

 

I started a thread on rebuilding original chevy mechanical fuel pumps Danny...you could rebuild yours on my thread maybe?...huh?

 

I've had several friends lose their mechanical fuel pumps on long distance cruises. Enough to where if I'm traveling any distance from home, I pack an extra, if not for me, than someone else.

 

IF that long.....the last new one I bought (sbc) from NAPA lasted about 50 miles before it crapped out.....

 

You have an extremely rare fuel pump. Those that die on the driveway rather than far away from home are rarer than complete Ardun heads.

 

they make some good noises and belch lots of oil first

 

When I was a lad my dad spent most of a Sunday trying to figure out why our old '58 Merc brandy new fuel pump wasn't working, after we changed out the old one because the diaphragm failed. Finally figured out that one of the one way valves had been installed backwards on the new pump. Darndest thing.....

Interesting what you remember too.....I was probably about 12, and he and my mechanic uncle were working on it, it was cold as hell in the garage too, natch.

 

Newer gasohol is tearing up the diaphragms on the older pumps. Fuel pump failure seems real common lately with both mechanical and electrical pumps

 

Alcohol in the gas is hard on parts that weren't designed to be used with it. You can also get a piece of crap from the tank or line stuck in a check valve. It's a good idea to put a filter before the pump.

 

I've had one quit like that, Running fine shut it off and it never starts again. Heck I had one that held pressure when idling and you could coast around that way but the minute ya gave throttle the pressure would drop to zero and quit.

 

Yeah,I have a filter between the gas tank and fuel pump. HRP

 

The last one I had go bad on a SBC just pissed gas out the weep hole. One I was able to make it home sputtering before it totally shit the bed on me. So its very possible for it to croak in the driveway, a very considerate fuel pump.

Bob

 

Had the return spring break and the pivot rod push out the side of the pump on the Suburban.
I zip-tied the choke on the 4bbl closed so it drew through just two bbls, and it pulled enough vacuum through the carb that it pulled fuel past the non-pumping pump. I drove home in 3rd gear (1:1) with 3.42 gears and tall tires--so long as I kept the RPM up, it ran fine, though a little on the warm side because it was running lean.
Went 200 miles that way and was doing great until I hit a parking lot on I-85 just north of the Georgia border.

-Brad

 

After you rebuild it don't forget to change the oil because if it ripped the diaphragm then you probably have fuel in the oil/crankcase.
Oh, and yeah, I had one just quit on me in the past and on the last car I bought the fuel pump didn't work when I got it. Both had badly deteriorated diaphragms.

 

I had one go out on a SBC years ago. It was a car that I had driven 90,000 miles and never gave the fuel pump a thought. When the fuel pump went out and I gave it a close examination I found that over time the lobe on the cam that pushed the fuel pump rod had slowly worn to the point that the fuel pump would pump no longer. It came on slowly, in fact if the car set overnight I sometimes had to prime the carb to get it running. The carb would leak down over night, in the winter I would prime it with starter fluid/ether. I used an 1/8" plastic oil line tube and drilled out the starter fluid nozzle so that the plastic line fit into it. I ran the line threw the firewall and into the original air cleaner threw an 1/8" hole I drilled in the side. The end of the line set just above the choke butterfly. One squirt and I was up and running, all from the drivers seat even in 4 degree weather.

You may want to inspect the fuel pump push rod travel.

 

yeah Brad,I remember towing you down the shoulder of I-85 with my wifes van. HRP

 

this is one of those items you want to buy an old used one,rebuilt it, and throw it in the trunk, I've had to rebuild a mechanical fuel pump back in 92 on a backroad following 66, I was smart enough to anticipate it possibly going out and brought a kit, it would have been much eaisier to swap a pump then rebuild the dam thing on the side of the road, having a known good one with you is cheap peace of mind