Tech Tip No. 10
Originally published in the quattro quarterly
Check Fuel Distributor Screen
Early this year at the quattro club safety seminar at the Portland
International Raceway one ur quattro (original turbo coupe quattro) with 99,000 miles had a lack of power problem while under boost.
The car had this problem as long as the owner could remember, and the owner had taken the car to several shops without satisfaction.
The car started and idled well, had plenty of boost from the
turbo. Temporarily creating timing advance for sea level intake pressure didn't correct the problem. An engine computer from another car at the track was tried. Still no power.
Both fuel pressure and control pressure was within specifications. The frequency valve was operating at the correct frequencies for all tests, and both fuel filters under the car were recently replaced.
Here's what we found. . . The small screen that is installed
inside a hollow banjo bolt at the input to the fuel distributor was mostly plugged.
This screen was only intended to catch particulate matter created during manufacturing and assembly of the car. This screen is normally removed by the dealership as part of the 1000 mile maintenance. With the screen removed the car again had power.
While this one occurrence is less than 2 tenths of 1% of the ur
quattros in North America, it is something that all owners may want to have have checked to verify that it was actually removed.