Questions and Answers

Volkswagen Jetta Is Dumping Fuel Q. I just found your site, and it is great! Here is the problem I am having: I have a 1987 Volkswagen Jetta GLI with 130,000 miles, manual transmission and A/C. It is the 1.8 liter CIS-E fuel injected engine. My main problem is that I am getting too much fuel in the cylinders. The fuel pump never stops pumping from the time I turn the switch on.

It will run and idle fine for a while, but will eventually flood itself out, evidenced by wet plugs. I was having a problem after driving for a while the car would loose about 75% of its power and eventually flood out and not start. After setting for an hour or so it would start back up and do the same thing again.

I replaced the catalytic converter and that seemed to stop the lack of power problem, but it still floods out. While running, the exhaust is putting out a blue smoke that is pungent. Could you please give me a place to start finding this problem?

Thanks,
Dave

A. Pungent blue smoke is oil burning. Excess fuel would give out black smoke. I would have to see the spark plugs to be sure, but I think that wet you're seeing on the spark plugs is oil.

The fuel pump is supposed to run while the engine is running. If it runs more than five seconds with the key ON and engine OFF, then there is a problem.

It is possible the fuel injectors are dumping fuel. The CIS-E fuel injectors are susceptible to dirt and the internal springs get weak over time allowing them to open sooner and longer. There is a special cleaner/tester for CIS injectors. It cleans the injectors, holds pressure on them to see if they leak and measure the pressure they open at. New injectors should be tested before they are installed. Sometimes new injectors are just as bad as the old ones.

It is also possible the fuel pump is putting out too much pressure. A typical fuel pump is capable of putting out over 100 psi of fuel pressure. So I would start with a fuel pressure test to see what, in fact, the fuel pump is doing. With the fuel pressure tester on, you can check the fuel pressure regulator as well.

Proper fuel press is:

• System Pressure: 5.2 to 5.6 bar (75 to 81 psi)
• Differential Pressure: Connector disconnected from regulator: 0.2 to 0.5 bar (3 to 7 psi) below system pressure

There are some adjustments that can be made to the fuel distributor. You need special equipment to properly set it so I would recommend letting your Volkswagen Dealer make the adjustments.