Fuel Pump Manual Operating Characteristics

[LegionPiper]

Hi there folks,

I've recently replaced all Fuel Lines from the Tank to the Pump.

The truck starts and turns over, however sputters out quickly.
There are no line leaks anywhere.
I primed the line attached to the Carb with gas and the truck, ran fine, then quit a short time later.

I removed a gas line Filter between the Carb and Pump.
When I manually pump the gas, it is not a steady stream that comes out, but rather, like a coughing drowning victim.
If I put my finger over the hose and pump, I can feel air pressure pushing upwards.

The TM test for the fuel pump pressure is at idle ( Which is not happening at this point )

Any ideas guys ? Is it possible that the diaphram's in the pump dried out when the line let go ??

Thanks

[LegionPiper]

Hi folks,
found a great test procedure in the CDN TM. ( CDN-VEH-D114)

Page 15 Para 179
"Disconnect fuel pump to carburetor line at carburetor and attach a bleeder hose to Fuel Pump.
With outlet of bleeder hose at Carburetor level or higher, the flow of fuel should be at leaast on pint in 45 seconds of engine operation at idling speed of 450 revolutions per minute "

There is also an excellent rebuild section in there as well.

[NAM VET]

good afternoon, LP. Sitting here in our sunroom, drinking hot coffee, and half way thru one of your wife's cookies. We have I think three left to share. Not sure my PM got to you, but thanks a lot for them. And the recipe for them. HC

[LegionPiper]

That's fantastic !
I'm really happy that you received them and they arrived in good condition.

Great news during these crazy times.

[LegionPiper]

One last question on this thread.

I have a Fuel Pump coming from MidWest today.

The TM makes no mention whether the Oil needs to be drained first from the pan ?

There is a gasket there, so I assume that oil is channelled somewhere here ?

Anyone pull one of these puppies ?

[ashyers]

LegionPiper,
No need to drain any oil, the level is below the pump. What the pump sees is splash lube.

Once you get the pump installed you can use the priming lever to prime the pump and ensure all you fittings on the pressure side are leak proof. If you have an issue with priming the pump check to ensure your inlet lines are tight. If loose the pump won't draw enough vacuum to prime.

Andy

[LegionPiper]

Thanks so much Ashyers !

I did have some issues with the link between the line under the Rad connecting to the ShutOff Cock.
( Slow leak ) once I removed the Shutoff Cock, the leak was repaired.
( I am assuming that this particular end is a little longer than the others along the gas line. )

However, is it possible to have a gas line connector suck air but not leak gas ?

Thanks again, I can hardly wait to put in the new Pump this weekend !!

[ashyers]

"However, is it possible to have a gas line connector suck air but not leak gas ?"

Sure, if there's no gas in it due to a pump that won't prime .

[LegionPiper]

LOL
Yuppers that would do it.

Interesting find ...

The Old Fuel Pump was full of oil in the bottom vacuum section.
I'm guessing that the gaskets are cooked in the pump and engine oil is leaking into the bottom ?

This might explain my burning oil issue since the line goes straight into the Intake Manifold.
The line to the windshield wipers is blocked off.

last question, the pipe connectors were sealed using teflon tape, which I thought would not be a long term solution.
Do you guys use permatex for the threads ?

Thanks

[Kaegi]

shouldn't need anything on the pipe threads in automotive applications though it wont hurt anything if you do. tape will just desolve in fuel or oil so is a waste of time. good clean pip=e threads pretty much never leak

[QCIM37CDN]

Another thing to check is your fuel tank cap. I found that my truck was starving for fuel. I have a transparent inline filter, before the fuel pump, and I noticed that it was bone dry when the engine was running! Also found that removing the cap when the engine was running, resulted in a a big gulp of air going down the filler. After double checking that the vent in the cap was, indeed, open, I tried leaving the cap a bit loose. Problem solved. The filter is now full when the engine is running, and the truck no longer starves for fuel.

[LegionPiper]

Hi folks,
put in the Fuel Pump today and got the truck running.
I replaced the output port on the pump as the old one had been stretched, that was the hardest part to find.
( It turned out to be a 3/8-18 NPT Male to 5/16-20 Inverted Flare. )

The truck started right up ( Thanks again to the great rebuild from Midwest )
Sure enough, it no longer burns oil, so the old one was indeed leaking oil through the vacuum pump.

The fuel pressure is much better and the truck has never run faster.

Nice when things actually work out.

Plus no leaks at any joint, without the use of any thread compound.
Thanks guys for all the help.