Hello and Fuel Pump Options

[derelict74]

Howdy folks, new to the 914 world here, ( not to VW's had lots back in the day...)just aquired a 74 2.0 that was allegedly the restoration project of the laziest man alive for the whopping price of " I don't want to deal with it" ...ie zero.

now to the tricky part, it's been sitting for many moons, and the sum total of his restoration was to take random things apart , and make my life more difficult. (IMG:http://www.914world.com/bbs2/html/emoticons/spank.gif)

So right now I'm trying to get it started , as I'm moving in two weeks, and it would make my life much easier if I could actually drive the thing the 30 miles to the new place ( I'm probably dreaming, but it's worth a shot)

anyways on to the fuel pump. I can get the pump to run, but when connected to gas, it just fills up with gas, and stops.

gas appears to be getting in through a small hole ( 1/8 or so ) through into the motor from the pump chamber.

Is there supposed to be something in there that's fallen out? cuz as it sits, I don't see how it could possibly NOT just fill up the pump with gas...

if I can't get this thing to work reliably, I'll get a generic pump ala one of the ones listed in this thread... http://www.914world.com/bbs2/index.php?act=...f=2&t=32241&hl=

So, any bright ideas out there?

cheers,
ryan

[Trekkor]

Check the relay in the engine compartment before you spend any money...

They get corroded.
Welcome on board.

KT

[MecGen]

Hello
Welcome to the club !
Where is Chemainus ?

If its been sitting a while the first thing to do is take out the tank and clean it. You would be surprised at the crap that fall out a 30 year old tank. This junk always seem to make its way around to the worst places. blow out the lines.
Make sure you have a strong 12 volt source, making the pump guttless. Relay boards are an issue with these cars.
The oem fuel pump works well, for a long time, but I am really unfamiliar with "alternative" pumps. I switched to carbs a long time ago.
Just checking...you still have the FI ? As you know, Carb and FI pumps are different.
Any factory, pre- unleaded days, pump ...have a risk of screwing up after sitting too long, the older pumps were designed with the lubed (lead) gas in mind.

For your bits and pieces you can check the classifieds, or keep an eye out for "sawzall party". Most guys will take it apart and ship it to you. This is an awsome club for these types of things. Have you checked the 914 Resourse pages?, you might find a solution for some of your "random" needs.

Have a seat and stay awhile...

Later
Joe

(IMG:http://www.914world.com/bbs2/html/emoticons/beerchug.gif)
I been in the VW crowd, lots of VW guys here.

[derelict74]

electrics are fine, or mostly, doens't seem like the mice ate anything too important..., the pump will run for a while, after I take it apart and drain the gas out of it....

Fuel tank is one of the things he'd removed so it was all drained and reasonably clean.


So basically it's not so much an electical issue, as one of keeping the gasoline out of the inner workings of the pumps electric motor...

guess it's a question for the other cheap buggers out there who've tried to fix their own fuel pumps....

and what's supposed to be in that little hole in there...

thanks for the help guys. all the parts are there for this car, their just in a bunch of unlabelled boxes in the shed...

once I've established that the engine does run and that the tranny isn't humped (two things that would turn this from a fun project to another money pit I don't need) I'll deal with the rust...passenger side rocker is ugly, but my rusty old landcruiser has given me a fair bit of practice at welding and fabwork, so that part I'm ok with.

So yes. I think hell hole is a rather good name for that spot under the battery.
cheers,
ryan

[mihai914]

Hi and welcome aboard!

First, could you post a picture of your pump just to be sure you have the OE one.

Second, the fuel pump circuit is designed that when you turn the ignition key to the ON position, it will energize the pump for two seconds and then turn it off untill you start the engine.

If the engine cuts off so will the fuel pump for security purposes.

The fuel pump is also designed to have the motor cooled by the fuel going through it.

The question is are you getting any flow down to the injection system?

Your pump may be wrongly connected, you may have a kink in the supply line or even a blocked line from old gas.

We will need more info on you setup and symptoms.

[derelict74]

pump is the OE one, ( sorry no digi cam, and rather less pic posting ability....) I had a look at a bunch of the old threads on here, and it's Identical to the others..

anyways, pretty sure its hooked up the right way, the essential issue here is that I have a buggered pump...

it's possible I suppose that it's pumping against too much pressure from a blocked line and that's forcing the fuel back into the pumps inner workings, but frankly looking at the steel vanes of that pump, and the hole inside that chamber that is rather large by comparison , I think something must be missing ( some tiny widget that dropped out when I took it apart perhaps? )

When you say it's designed to be cooled by the flow of fuel, where is the fuel supposed to run to cool it?

fuel is making it all the way to the armature on my pump, hence the difficulty
While it works ( for those 30 seconds before it floods with gas and dies) it does turn on for 2 seconds with the key, and run when I'm turning the engine over, so things do seem to be working properly in that regard.

Heh, it's been ages since I've owned a vw , I've had a diesel landcruiser for the past ten years, but I think my parents tallied it up once, that between all of us in the family we'd owned something like 40 odd vw's....(and my dad had a 1960 356B that was mint and the bastard sold it when I was 15....)

kinda fun swearing in german again...

cheers,
ryan

ps, chemainus is on Vancouver Island....waaaaaayy our west.

[mihai914]

Well I can shoot a picture tomorrow of the internals of a working pump.

The ports on the pump have to be mounted a specific way also like in this picture.

I don't know if it's supposed to be cooled right down to the armature.

[bd1308]

sounds like you toasted the pump....or it sounds like everything works fine and you just need to keep on crankin' to get that fuel flowing

[redshift]

The fuel cools the pump while it's on it's path thru it.

There is a valve that keeps it from cavitating, seems you have no valve, or it's not working.


M

[derelict74]

yep thats the pump I have, and looks like it's mounted in pretty much the same orientation.

anti cavitation valve....hmmmm this could be the problem....other than the steel pump impeller, and the five little "bearings" there arent any other moving parts inside...

guess I need to see another pumps innards....

thanks for all the help guys !

cheers,
ryan

[davep]

The computer allows the pump to run a few seconds, to build pressure, when the key is turned on. The pump will not start again until the computer sees enough RPM to indicate the engine has started.

If you get vapour lock, the only way to get fuel into the pump again is to repeatedly turn the key on, then off. The pump makes a lot of noise until it is full of fuel. I realize this is not the problem at present.

I take it you have found the pump connections diagram and the fuel system diagram. The fuel line routings are very particular for correct operation. You have to use the correct fuel filter for the year. You have to use the custom hose; tapered to adapt a large line to a small line and about 3 to 4 inches long. You need to use the correct type of line clamps; common gear clamps are bad news, since they cut into the hose over time, relax and cause a fuel leak under high pressure. You don't want to use fabric covered fuel hose, and you need to get high pressure gasoline rated fuel line. Even the injectors need a lot of attention; no fabric line on them, this was a recall item. The injectors have two seals on them; the big one for the clamp, and the small one for the tip. The tip seal is critical since it shrinks under high heat and drys out; you cannot allow an air leak here. The injectors tend to leak where the plastic is bonded to the metal; this is the prime cause of 914 fires. Check the plastic lines for cracking / crazing, this will lead to failure quickly.

The pump is supposed to be flooded with fuel. It has in, out and bypass ports. The bypass is Y'd to the regulator bypass and to the return line, the smaller of the two lines to the tank.

[mihai914]

Here are some pictures of internals.

[mihai914]

In the previous one nevermind the orientation of that big plate, I'm sure it's not in the correct position.

[mihai914]

Last one clearly shows that the hole you are referring to is supposed to be there and is provided for cooling. I bet if crap gets in there and either rusts the pump or blocks it with varnish the pump motor will not cool very well and cause you alot of weird problems.

[MecGen]

Hey Dude
I'm raised in Vancouver !
Great to have you aboard !
BC connection
These guy are strong in VW, but for gods sake don't ask them about a 914. Average prices, good service, real bad 914 tech support....don't ask... (IMG:http://www.914world.com/bbs2/html/emoticons/icon8.gif)

Later
Joe

(IMG:http://www.914world.com/bbs2/html/emoticons/beerchug.gif)

[derelict74]

Ok, so, that hole is supposed to be there, and nothing goes into it...

Man that just seems fuckin bizarre...having the whole motor casing totally full of gas....

Good tho I guess, means I didn't lose any tiny little parts.

Many thanks for posting those pics !!

So, then what gives, last time I had the pump in there, I'd turn the key on, and it would run for 2 seconds, then stop, I did that a few times, and then it wouldn't turn on anymore.

crawling underneath with some jumper wires I tested it with direct 12v, and no go. brushes had stuck ( and apparently the fact that I had to dump a cup of fuel out of the motor casing wasn't the problem... (IMG:http://www.914world.com/bbs2/html/emoticons/screwy.gif) )

So, if it was trying to work too hard and couldn't move the fuel past a blockage I suppose that could happen....

hmmm. further testing is required methinks. but all in all judging by the depth of the grooves the brushes have rubbed into the comm, I'd say the pump is well aged, and could be a tad feeble...

but, I spose I'll have to crawl back into that horrible place and reinstall it again....man, cars been mine for about a week, and I'm already whining (IMG:http://www.914world.com/bbs2/html/emoticons/laugh.gif)

cheers,
ryan

Vancouver eh JoeSpark? man I'm a-skeered of that big city...I just hide out here on my island in the woods....