bosch fuel pump

[otto]

hi guys,

sorry if this has been covered to death but i couldnt find what i was looking for in the search.

i just recieved my new 910 pump and noticed on the outlet side it has that fitting for a banjo conection (ie, holes around the side) and a hole on the top at the end of the threaded bit. i just wanted to know what was the pourpose of this fitting and weather or not i could replace it with a normal fitting that would resemble the intake side as it seems abit disfuncional to have a banjo fitting coming off at 90 degrees if im going to mount it in tank. i can see a little spring in the side holes which had me wondering if it was a check valve aswell???

thanks.

[C_DawG]

Nah i wouldnt replace it with a hose barb or anything, its a sorta one way valve thing, top stop fuel running backwards through the pump I guess.

I just used a banjo, cap nut, and a loop of In-tank hose from the banjo to the top of the bracket. Double hose-clamped it at both ends.

[C_DawG]

Oh btw, dont use those hose clamps that are like threaded strips that pull closed, they tend to cut into the hose. Use those ones that are internally smooth and just have a bolt at the top.

[otto]

cool thanks, i thaught it surved a higher purpose. I was abit confused cause ive seen some photos in other posts where it seems like the outlet hose just goes straight up (no banjo).

Does the cap nut block off the hole at the top??(sorry just not to familiar with the banjo).

does anyone have a pick of this setup?

[C_DawG]

Yeah the cap nut blocks off the top. Its a Dome nut type thing.

Ive seen those straight up type connections, but we figured that Bosch wouldnt put a valve on there for no reason so we got the Banjo fitting.

[JimX]

The banjo fitting isn't necessary. With my 044 I couldn't find one that fit the ball bearing valve on the top of the pump. Spoke to a few people, the consensus was that it is to stop fuel running back down into the tank, but that it's not necessary. So I took it off and fitted a standard barb connector and it's never had a problem. Not even extended cranking after sitting idle for 2 weeks. The 044 primes so fast that the valve isn't needed.

Since you already got the banjo fitting that's good, but if anyone else out there can't find one then you don't need it.

[otto]

what does the standard pump have to keep pressure (stop fuel from running back to the tank) in the supply line when the pumps not operating?

[JimX]

Nothing that I know of. The only thing I can think of is that the valve would keep the fuel line under pressure even when off. I don't think it would all drain back down into the tank, because that would mean air would have to get in the line. Where would the air come from? The regulator should stop any air coming back through the return line. Get a straw full of liquid and hold it by the top covering the end to see what I mean.

[otto]

that makes sense, i know the supply side of the pump (standard)holds pressure though cause when i disconected it just after that fuel tank cap once it spray out fuel everywhere.

i guess if i cant find the banjo ill get a barb fitting. do these pumps always come supplied with the banjo fitting?

[otto]

sorry that was abit hard to understand i ment when i disconected the fuel line just after the cap(on the outside of the fuel tank) where the hose connects to the cap. if that makes any sense

[JimX]

The pumps don't come with a banjo fitting, that's why I had to remove the valve. Sorry I misread your post, I thought you already had a banjo fitting for it

I went to Pirtek and Earl's who both have a bazillion connectors, and neither had a banjo connector of the right size. I spoke with the guy at Earl's and he said it shouldn't be necessary, and a couple of other people have told me likewise since. I've still got the valve though, in case someone comes up with a good reason for putting it back on and gives me a banjo connector to suit. But until then it stays in my spare parts box.

[otto]

sorry i meant do they alway come with the valve, I wonder weather the valve is just there as an option to fit a porticular make of car. it ticks me off how they supply us with this wiz bang valve thats impossible to get fittings for.

oh well seein as ur in syd and didnt find the fitting it looks like ill just have to remove the valve and get a normal fitting for it,

gives me a bit more confidence doin it this way knowing its already worked for you.

[lukits01]

Just wondering,

arent the 910s meant to be an external pump?

The power (+/-) wires arent exactly perfectly sealed

if by some act of misfortune a short happens wouldnt it blow the tank?

[JimX]

You won't blow the tank even with a short. For a start, there is no air in the fuel, and you need air to have a fire/explosion. Secondly, even in the air above the fuel (if the fuel level drops below the pump) there are too many fuel vapours for it to ignite (ie, too rich a mixture). And thirdly, consider this - the fuel pump runs off 12v. The spark will be 12v. Your ignition system runs off 10's of thousands of volts, and even then sometimes it fails to ignite even when vapourised and at the correct mixture (think cold cranking on cold winter's morning).

Put it short (no pun intended) you're not going to blow up even if you botch the wiring

[T0nyGTSt]

So you're telling me that all these movies with cars that explode with the lightest taps are fake???

Say my mobile rings in my pants pocket when I'm filling up at the servo? My balls won't spontaneously explode like the sign says?

btw. does anyone have a list of all parts you need to get from Earls to installl an 044?

T.

[lukits01]

So there is absolutely nothing wrong with mounting an external pump inside the tank?

even though the voltage wires are not sealed at all?

What if I mounted a 910 outside the tank with the stock pump as a lifter?

and no surge tank?

[JimX]

My 044 has exposed wires. There'd be no way to really seal them on an internal pump I don't think, fuel has a very low surface tension and it gets through everything easier than even water would. If the circuit is good then there's nothing for it to spark against anyway.

If you really want to test it, get a car battery and a small amount of petrol, and try sparking it with wires to make the fuel ignite. Do it under the most favourable conditions you can think of. See how hard it is to do, then imagine it being 100 times harder in your isolated fuel tank where you couldn't even breathe the air above the fuel due to the vapours.

It's just not going to happen. I've read about stories where people accidentally set fire to their petrol tanks through the inlet (usually through static grounding of the pump), and there's only a tiny flame despite it being above 50 litres+ of fuel. The only place it burns is where it's getting enough oxygen from, which is the inlet. So you can stop it just by putting the petrol cap back on.

Btw Tony, I saw a promo thingie on the History channel today about engineering's greatest failures. They had a bit where they showed a Pinto getting rammed from behind and exploding. I'm pretty sure that the main reason Hollywood picked up on the "crash -> explode" car phenomenon is entirely due to that great piece of American engineering. What I want to find out is where they picked up on the "crash head-on, then immediately vault into the air doing a torsional twist in a graceful arc before crashing back onto the ground" thing. Various movies/series spring to mind that do this, but the one that sticks in my head the most is the A-Team series from the early 80's. I don't think an episode went by where that didn't happen at least once.

Sorry, I'm just ranting. It's late and I need to go to sleep.

[C_DawG]

Guys dont go to Earls or Enzed or Pirtek or whatever for banjo fittings.

Just got a diesel engine place, Trucks use heaps of 12mm banjo fittings in their fuel system. I got a Banjo and cap nut for $5 from Trickies Diesel. With copper washers also.

[jvs007]

the only thing that is covering the terminals on a factory pump (r32 gtst) is a little rubber cover for the positive lead terminal, the negative terminal is exposed bare. So if out of the factory they werent worried about sealing these connections then why would we. As long as the wires are crimped properly and nut screwed on tight, it shud be kool.

i pulled the banjo fitting supplied with the 910 off and didnt use it.