Volkswagen Repair: 1989 VW cabriolet stalls, spark plug wires, 1989 vw cabriolet

Question
I have a 1989 VW Cabriolet that stalls. The temperature light comes on and flashes but I have replaced the thermostat and the thermo radiator fan switch. The fan works and I checked the circulation and that is fine too. I have also replaced the fuel filter as well as a couple of bad vacuum lines and checked the timing which is right on the money. I even checked all of the spark plugs, regaped them, checked the spark plug wires and the distributor cap and rotor all of which were fine. The car still stalls. This is what happens: On the highway it is fine but when I drive the car in town for about twenty minutes sometimes more it begins to stumble when I slow down and then it will stall if I come to a stop or almost stop. Now it doesn't make any noise like a clunk or a bang or even squeal to give me a clue as to what is wrong. It just stumbles and dies! What do I do? If I knew what was the problem I could fix it. I hope you can help me.
P.S. I do not know how many miles are on the car because the odometer stopped working but the car is perfect visually and makes no engine noise like a lot of older VW do. Thank you in advance.


Answer
Brian,

The first thing you need to do is take out the new fuel filter and drain the fuel into a clean jar.  If the fuel is a cloudy rust colour, let it sit for 24 hours and see how much rust settles to the bottom of the jar.  I think you have fuel contamination from your metal gas tank.  If this is true then you'll find that it has contaminated the entire system and you'll neen to replace the parts.
Check the top of the filler neck for holes aswell, that where water can enter the system as well.

If you want to save a lot of money, buy and old Jetta or Golf as they have the same fuel system, but a plastic tank.
First check the colour of your fuel distributor (Black is CIS, and Silver is CISE), yours should be black (CIS). Buy a wreck with the same system, they're not interchangable.

You'll still need to purchase a new metal gas tank and a new fuel pump for a Cabriolet, but your fuel distributor, pressure regulator, injectors, and injector lines are the same as the Jetta or Golf.

Good Luck, it's a big job,

Paul