TheSamba.com :: View topic - '85 Cabriolet fuel pump questions (VW newb warning)

Sun Aug 28, 2005 10:34 am

So I've spent the last 45 minutes searching through the tech posts here and haven't really been able to answer my question. I have an '85 Cab. that isn't pumping fuel. I'm relatively good with a wrench (rebuilt several V8's) but am new to the VW world, as well as this site (obviously). I have a Haynes manual on the car but on this matter it's about worthless.
I've tracked the lack of fuel to the external fuel pump but I've seen a few posts here that mention an internal pump as well. Are there two pumps? If so where can one pick up an external pump? (The local Autozone is worthless.) If the external pump doesn't resolve the issue what all does it take to remove a gas tank in one of these things? Are there any decent write ups or technical websites specifically on Cabriolets?
Any insite would be appreciated. Thanks for the site, looks pretty cool.
Darren

Mon Aug 29, 2005 8:09 am

Yes there is a pump in your tank. I think the Scirocco and convertible models got this setup before the other VW models actually, towards the end of the 1984 model year. The tank "transfer" pumps have a reliable lifespan of about 10 years. Beyond that and they are not to be trusted. (I carry a spare in with my spare parts in the back of my 85 Golf) The main pumps very seldom die, there's been a lot of main pumps replaced over the years when they were just fine because people don't check that transfer pump in the tank.

To access the pump, you don't have to pull the tank. There is access inside the car. Pull up your rear seatbottom cushion. There will be an access panel towards the passenger side of the car, held down by three screws. Under this is the combined gas guage/fuel pump assembly. Label the hoses, disconnect them , then unplug the electrical connection. On a cabrio I think it's a twistlock setup, you have to get a large channellock and get it situated between two of the openings on the rim of the combined gas gauge sender/transfer pump holder and twist counterclockwise about 1/5th of a turn. Then the assembly will come out, straight up. Best not to do this with a full tank of gas, by the way.

But before you loosen anything to remove it, you can always do some checks on the pump - if you know how to remove the fuel pump relay and replace it with a jumper wire with some male plugin connectors crimped to each end. Both pumps should run with this bypassed, usually you can hear and feel the pump running there where the connector plugs in under the back seat. Unplug it while it's energized and you will usually be able to hear the difference as the pump turns off. Then you can remove the outlet hose from it, connect that to a 3 foot long piece of fuel hose in a container of some kind that holds at least a quart, and then connect the pump to power again, and see if/any fuel comes out. I think it's supposed to be like 13.5 ounces in 10 seconds.

transfer pumps are much cheaper than the main pumps, by the way. here's one for 60 bucks on eBay.

http://cgi.ebay.com/ebaymotors/VW-in-tank-fuel-pum...enameZWD1V

andy

Mon Aug 29, 2005 10:23 pm

I'm on my 5th A2-chassis VW('85-92 Golf/Jetta), and I've had to replace the transfer(in-tank) pump on 4 of them....not a one has needed the main pump, and the lowest mileage car had about 190K on the ticker.

The factory-installed VDO-brand pumps were the most problematic; here is a brandy-new Pierburg pump for about the same $$ as the Ebay one.....and I'm positive the customer service, quality guarantee & shipping are better here than from an Ebay seller anyway:
http://www.germanautoparts.com/Volkswagen/Cabriolet/Fuel/98/1
Don't forget those three clamps too - the factory ones are the 'one time use' type.

The 2-pump system was installed after 1985 model chassis number 000122, and continued through the end of the A1-chassis Cabriolet production in 1993.

Mon Oct 03, 2005 10:15 pm

yep, that's(transfer pump) what was wrong with a cab that I got. Actually it was just the piece of hose that connected the pump to the metal hose on the sending unit. Nobody could figure out what was wrong with it. 3 or 4 mechanics, etc... I did some research, and that was it. The car would run real crappy as the weather got warmer. then if it got above 75 degrees outside, it would just not run, it would start spuraticly, but not run. the only thing I have heard of that ever killed the main pump was running it out of gas, it is lubricated with the fuel that runs through it.