TheSamba.com :: View topic

Mon Mar 01, 2010 6:15 pm

I drive a 1976 Wesfalia, 2.0 liter. I'm having a problem with it acting like it is running out of gas after I drive it for an hour or two. It will sit and idle just fine !! Everything is new (engine, carb, fuel pump and filters). There isn't a relay on the power source for the fuel pump. With no relay could this make the FP act like this?? If not my next step will be to pull the fuel tank out to see if there is something restricting the fuel pickup.

Mon Mar 01, 2010 6:23 pm

When it dies is there fuel in the carb(s) bowl?

Mon Mar 01, 2010 6:30 pm

It's protesting the shitty carb setup because it wants its fuel injection back.

Mon Mar 01, 2010 7:22 pm

Where is your pump getting its power from? Coil? You say this happens after a couple hours of driving? So an hour is okay? I would look for blockage in the tank, no need to drop the tank right away, drain the tank, remove the fitting and check the screen. There is a chance the pump is getting hot after a certain amount of run time and not pumping, but then you say it will idle and the pump does not care if you idle or run 100mph it provides the same amount of fuel unless it is getting hot and slowing down the flow. When this problem happens have you put your hand on the fuel pump to check if it is hot? Also put your hand on the coil, maybe it is getting hot and breaking down, that is a wag.

Mon Mar 01, 2010 7:29 pm

Double check to make sure your tank is venting properly. When it dies out open the gas cap if it hisses then your vent lines might be pinched or clogged.

Mon Mar 01, 2010 7:37 pm

My pump gets it's power from the coil. If the car starts to die, I can push in the clutch and it will continue to idle. Once it starts doing this, it will start to die as soon as I try to get into 2nd gear. It acts like its not getting enough fuel. I have even changed the setting on my fuel regulator to see if that makes a difference and it doesn't!! I did check my gas cap and there wasn't any pressure built up in the tank!! The fuel pump doesn't feel hot.

Mon Mar 01, 2010 7:42 pm

I think I would power the pump up via a fused relay myself. LIke this...

http://www.germansupply.com/home/customer/product.php?productid=16928&cat=&page=2

Mon Mar 01, 2010 7:58 pm

Randy in Maine wrote: I think I would power the pump up via a fused relay myself. LIke this...

http://www.germansupply.com/home/customer/product.php?productid=16928&cat=&page=2

This goes back to my initial question(purpose). Does this relay help keep a better power source to the pump and by getting my power directly from the coil could it be affecting the pump???

Mon Mar 01, 2010 8:04 pm

Never happened to me, but some folks that do that have said that after the coil gets pretty hot (like after a decent long drive), the coil is no longer able to supply adequate power to both the engine and the pump.

If it were me I would use the relay.

Mon Mar 01, 2010 8:09 pm

Randy in Maine wrote: Never happened to me, but some folks that do that have said that after the coil gets pretty hot (like after a decent long drive), the coil is no longer able to supply adequate power to both the engine and the pump.

If it were me I would use the relay.

Thanks Randy !!! I think I'll order one and change things around. While I'm waiting for the parts to arrive I'll drain the tank and see what I find on the screen.

Thanks Again to all that responded!!

Mon Mar 01, 2010 8:15 pm

Before you do anything else, you should install a fuel pressure gauge so you can monitor the pressure. If the pressure is steady you can rule out the fuel system - however it is acting like fuel starvation.

The coil gets its voltage throgh the ignition switch and then from the battery. It is unlikely that is the culprit but on GP I would not overload the switch and would do as Randy suggested by installing a relay.

If a gauge rules out the fuel pressure, what kind of distributor set up do you have? If it is points check them to be sure they aren't burned and if they are replace the condensor. If you have an electronic ignition then try another one. Sometimes when electronic circuits die they do so under load. It may be strong enough to support idle but be breaking down under load. I've seen other electronic ignitions die this way. My CJ7 and a friends Ford did it just like you are describing.

Mon Mar 01, 2010 8:48 pm

I have this type of double relay on both my buses.
http://www.paultaylorimaging.com/VW/Fuel_Pump_Relays/Fuel_Pump_Relays.htm

You did not mention which style pump and where it is located, too much head on a pump and it can cavitate and not provide fuel. A rotary style needs to be flow fed, a Facet style can draw a 12" to 18" head depending on model.

Tue Mar 02, 2010 5:12 am

Dondobe wrote: I'll drain the tank and see what I find on the screen.

Unless you've cchanged it to an earlier tank, your '76 doesn't have a screen in it.

Tue Mar 02, 2010 8:14 am

In addition to the previous replies and suggestions made, it would help if you could supply this info:

Type of Carb and fuel pressure it likes

Type of electrical fuel pump and pressure range it puts out

Whether or not there is a fuel pressure regulator installed, and
if so, what kind

Fuel pressure you are getting now to carb after pump/regulator

Tue Mar 02, 2010 9:53 am

Carb is a Weber progressive/ 3-8psi range (new), fuel pump is Airtex 2.5-4.5 psi, fuel regulator (set @ 3 psi)
I'm going to check pressures today.
This bus runs GREAT until this happens. Then it's a pain in the ***!

Jody '71 wrote: In addition to the previous replies and suggestions made, it would help if you could supply this info:

Type of Carb and fuel pressure it likes

Type of electrical fuel pump and pressure range it puts out

Whether or not there is a fuel pressure regulator installed, and
if so, what kind

Fuel pressure you are getting now to carb after pump/regulator

Tue Mar 02, 2010 11:36 am

May not of come from the factory with a screen but that does not mean a PO didn't put one in, I removed one from my 78 when I got it, and have pulled them from many later bays. Also fished out several red rags over the years.

The progressive does not need a regulator for that pump, but having one is okay as long as the regulator is not causing this problem. Where is the pump mounted, under the vehicle or in the engine compartment? I am guessing but the Airtex you have is a 8016S solenoid type?

Tue Mar 02, 2010 9:06 pm

Yes my pump is the 8016s and now I'm at a real loss, THERE WAS NOTHING IN MY TANK !!!! It was clean and did not have a screen.
I checked the pressure and it was 4 psi at the carb. Tomorrow I plan on putting pressure gage in line so when it happens again I can see if it changes.

busman78 wrote: May not of come from the factory with a screen but that does not mean a PO didn't put one in, I removed one from my 78 when I got it, and have pulled them from many later bays. Also fished out several red rags over the years.

The progressive does not need a regulator for that pump, but having one is okay as long as the regulator is not causing this problem. Where is the pump mounted, under the vehicle or in the engine compartment? I am guessing but the Airtex you have is a 8016S solenoid type?