TheSamba.com :: View topic

Thu Jun 14, 2012 2:37 pm

Hello,

I have just bought a 1975 pickup with the 1800 type 4 dual carb engine to accompany my 1978 bus with the 2000 FI engine.

The idle speed on the pickup is very high.
I have found a vacuum hose close to the fuel pump that is disconnected. If i connect it to the fuel pump, the idle gets a lot lower but then the engine loses a lot of power and hesitates when I accelerate. I have to rev up very slowly, otherwise the engine stops.

My conclusion is that the idle is high because of the vacuum leak, and when I connect the hose the engine doesn't get enough fuel.

But why? What is the purpose of the vacuum hose connection to the fuel pump?

Regards,
Joachim

Thu Jun 14, 2012 3:00 pm

Welcome,
I'm not aware of a vacuum connection at the fuel pump, the small hose on the fuel pump is a drain if that's where you connected it.

How about some pictures of your engine and these hoses? http://www.thesamba.com/vw/forum/viewtopic.php?t=6

And some of the truck too :wink:

Sat Jun 16, 2012 11:12 pm

Thanks for the quick reply and the welcome.

here's a picture of the pump and the hose.

And one of the truck:

Any ideas what the hose does?

Sun Jun 17, 2012 7:01 am

Bayerleiner wrote: Any ideas what the hose does?

No crystal balls or x-ray vision here, where does the other end go?

Sun Jun 17, 2012 8:11 am

Wildthings wrote: Bayerleiner wrote: Any ideas what the hose does?

No crystal balls or x-ray vision here, where does the other end go?

:D Point taken! It disappears mysteriosly behind the tinware. Just wanted to check if anybody knew anything about it before removing the tinware to see where it goes...

Sun Jun 17, 2012 8:13 am

start by figuring out what engine you have. Is it the original one? If so, hunt down a vacuum line drawing for the engine. If you play the experiment game you will get burned.

Sun Jun 17, 2012 8:59 am

The hose has been pinched between the piece of engine tin and the engine. Remove that piece of tin and the you should find the hose is only a few inches long, and goes nowhere. With the engine tin back in place the hose should be attached to the lower nipple of the fuel pump, the free end is just inserted into the obvious hole in the engine tin. I have always thought this is a type of breather tube that inserts into the tin to keep it clean(ish).

Gorgeous looking single cab. Nice find.