Engine started acting like running out of fuel. I limped it back to shop. Only showing 1 1/2 lbs at Schrader valve. Installed new Carter fuel pump, now showing 3 lbs when idling. Then dropping off quickly close to zero when increasing rpm. I changed fuel filter, no difference. Bypassed both fuel tanks and directly fed from fuel jug to pump. Still holding at 3 lbs but slower to drop pressure to almost zero in only a few seconds.

What are the odds both fuel pumps being bad? The old one has 10,000 miles. Manually operating the arm it builds up pressure and holds vacuum.

Is there anything else in the fuel delivery that can do this?

There are no leaks on top of engine. My other option is removing a lift pump from a running truck to confirm the new one is bad.

 

Which engine? N/A ot T? Are you sure your guage is correct? How did the new pump perform outside of the pressure reading?

 

Engine is all stock and original. No turbo in `86. The engine is missing on some cylinders as fuel pressure drops, Gauge is a 0-15 psi that checks dead on. Whitish smoke pouring out exhaust when pressure drops. Does not smell like antifreeze.

 

I would run some atf and or diesel kleen through the pump, I don't know exactly how it works, but there is a bypass that does flow excess fuel from the top of the ip,

It is mainly there to purge small amounts of air, as it goes to the top, from there, there is a fitting on the top of the return line, it's a small adapter coupling screwed into the top of the pump, that one goes to the return hose.

I would take it off and check to make sure the glass bead is in there and not stuck open, it might flow more fuel than is supposed to if it were stuck open.

That tiny glass ball pressurizes the pump properly, so it might do funny stuff if it aint doin' it.

That might or might not be it, but I would clean and check it out anyway..

3psi is a pretty normal pressure, and dropping a little is also normal but not really below 2 really, it can go lower as long as it has some flow, but not holding it, yeah, that's no good.

There might be something in the pump, if it's internal I don't know, except to run some cleaner through it and let it set over night, maybe clears it out.

 

3 psi at idle sound low to me. my facet produces 9 at idle and 3 at full throttle

 

I've been saying it for years on here, I just can't wrap my head around why people are still running mechanical pumps on IDI's. I know, I'm a broken record, I just don't get the resistance. I didn't even put either of my work trucks into use without electric pump conversions first. All those so many issues I've not had to deal with over the years due to those. The most; failing fuel selector valves, but those are rare.

 

^ X2,, just no, no mech fuel pumps

 

The OEM mechanical fuel pumps have worked great for me. They are simple and they track rpm. There's no reason that today's mechanical fuel pump replacements couldn't be great. But alas the reports keep coming in on early failures. Some guys carry spares. All made in slave shops using second rate materials and manufacturing. I wish some enterprising young folks would start an autoparts business, like Dennis Carpenter has on some items. I'd pay a lot more money for a domestically built part to OEM spec.
The epumps are also subject to offshore mfgring so buyer beware. I'm hearing of them not lasting as long as they should as well. The epump boys here will share their favorite. But it's likely made overseas as well. I'm still running an OEM mechanical pump. Lots of miles on it. Fingers crossed that it hangs in there.

 

The one International or Ford hung on the side of the block 40 years ago, I'm sure that one was good quality. ..

But I think all the repops are the same pump in different boxes, and they're garbage, probably not even really designed to function right to begin with, and fail real quick, causing engine to stop running on the road, or leak fuel into the crankcase.

There's no *reason some enterprising person couldn't make a good one, but here's why no one does

You'd be compteting in a captured and consolidated industry, owned by big equity industry investers,

If ownership of your factory was publicly traded, They would and do, offer you a lot of money to buy your factory out,

fire everyone, shut it down, and just put that same trash repop import pump, with a new label in your retail box.

The same people are majority stake holders of different sectors that coordinate, you'd be surprised,

mega investo bros is #1 shareholder on the board, of the factory overseas, the box and label companies, the wholesale dist, the shipping company, and the retailer,

If you persist in trying to compete with a small private factory, they have cornered everything, they have ways to undermine and eliminate you,

everything is geared to incentivise and protect consolidation monopolization, and vertical integration,

it's currently not a system or environment that really allows much horizontal growth and productivity, I'm not saying don't try. I wish it were otherwise.

they'll just buy the s**t stuff again and again.

few people will really search out a better replacement part to purchase outside of their ecosystem.

 

I appreciate what you say. I think it's economics. You can't really compete against low to no cost labor. And I said I wish someone would and charge accordingly for good materials and manufacturing. I'd pay for it. I bought a Ford truck to support union labor in the US. In the end you get what you pay for. That's when a lot of people were turning Japanese, I really think so. Double or triple the cost as needed over the junk to produce good parts. I'm old and retired, otherwise it would be fun to build a domestic company building quality parts. I hope some young person sees the need and fills it. I've already run a few businesses. It's time for my fishing pole now.

 

the Facet duralift pump is still made in Elmira New York. same place since 1950..
unlike 99.999% of the mechanical pumps which are made of chinesium with .001% quality control.

 

So what is the real life range of pressure that a pump should show? I have found minimum psi readings, as mine just barely squeaks by on.

The other thing I thought is a possibility of sucking in the small broken pieces of the pick up screen in tank. I am on the third one on the center mounted tank. The new pump first seemed to fix the problem when I took it around the block. But have not driven it anywhere since then. Now it is acting exactly the same as first pump.

 

That's great! The last of the Mohegans

 

Do you have dual tanks? Are you sure your FSV is working properly? If it's not indexing on one tank or the other that restriction can harm fuel pressure and flow. My Chiltons doesn't have flow and pressure for the diesel mechanical lift pumps, so where you would test it isn't shown. If you test flow and pressure before the filter it will be higher than after the filter as there will be losses through the filter. Some positive pressure is needed to supply the IP. As long as the flow is there the IP can pull some fuel as needed. Typical gas mechanical pumps deliver 5 to 7 psi to a carburetor, but that's a horse of a different color. Have you searched the internet for proper testing of the diesel lift pump? Hopefully some body can answer that question.

 

a properly working lift pump will supply 7 PSI pressure and 1/3 pint fuel from the filter heaad schrader valve in 10 seconds cranking.