Thread: Fuel supply probo....

[quote=scrambler;547368]I assumed it was a capped pipe and allowed for vapour pressure on the ambient 17 degree temperature...

You know I didn't. So how much difference does it make?

quote]

..........about 30 to 40 ft , and test methods state that the measurements should be taken at 26 Deg C - not 17

Yeah, no go on the old RRCs in the paddock, they're all pre 91, just spoke to ches, has eight of them apparently and with the Acco 6x6 and all the other gear we see....

anyhoo i'll be of to hillside in the morning an see what i can scrounge....i'll call you, johnE

GQ

to check the pumps pressure on vehicle...

Dissconnect the return line.

Cut the valve stem off of an extended valve stem from a truck tyre tube (or a unimog of someone you dont like)

remove the return line from the tank or after the regulator and install a length of 3/8th fuel hose put the cut off valve stem in this hose making sure its about 3 feet long and free of fuel then holding the valve up so that fuel cant flow to it apply a tyre pressure gauge and turn on the pump.

It will tell you the max pressure in the system and not if the regulator is cactus.

That's extraordinarily clever, thanks Dave. I can actually achieve this, and no unimogs will be harmed.

Note to Scrambler; muse all you like, I can do with some levity (and some (de)pressure pills, for me, not the fuel pump).

GQ

Quiggers,Am I right in assuming that when you ran the pump into a bucket it was still running after 20 secs but not much fuel was coming out?
The usual failure of a fuel pump is that it does not run.
For it to run and not pump is very unlikely.( it may be impossible)
IMHO, you may have a blockage in the pick up sock filter under the pump, or the hose upwards from the pump may be cracked.
I suggest that you take the pump out of the tank and have a look at it at this stage.
Look for blocked inlet sock, cracked tube upwards, maybe dirty burnt contacts where the wires go into the tank.
Regards Philip A

Look for blocked inlet sock, cracked tube upwards, maybe dirty burnt contacts where the wires go into the tank.

I suspect you might be on to something here. The shyte came from somewhere & went to the inline filter & the only thing in between is the filter sock, apart from the tube.
The flow reduced after 20 secs.

It is easy to imagine the type of shyte in the filter clogging up the sock though, especially if Q wasn't looking for it & it isn't all that big. Possibly allows enough fuel to get through to run the 20 secs.

I've got a hold of another fuel pump and it will be going in, first up tomorrow morning; came from a recent Holden and fits okay, I just have to do some wire work to adapt it.

Result wil be be posted soon...

the sock I removed wasn't foul...hmmmmm

maybe, after 290,000 ks, the current pump has just got a bit tired....

tomorrow will tell

GQ

the pumps can mechaniacally fail and electrically fail....

With a mechanical failure you get 2 types of failure

siezed in the pumping part or worn in the pumping part... seizing occours if you let it run dry or the strainer has fallen off and some crap has gotten into the pump.

Wearing is a PITA as the pump will run and generate flow when you pull the line of to check it for flow but it will make nada pressure.

Once you get a siezure electrical failure is not far behind but once youve got wear its very rare to have the pump electrically fail...

The wear type failure is increased if you get water in the fuel.

The strainer is pretty much self cleaning as its only designed to stop particals big enough to damage/sieze the pump, when you turn the engine off and the pump has stopped sucking fuel the sloshing action of the fuel dislodges most of the crud and it falls out.