I demonstrate how to test the fuel pressure in our 1988 VW Cabriolet. This test of the Bosch CIS system checks the system pressure as well as the control pressure and the function of the warm-up regulator (WUR). I purchased an inexpensive tester from Amazon which is linked below:
BETOOLL Pro Fuel Injection Pressure Tester Kit Gauge 0-140 PSI:
https://www.amazon.com/gp/product/B01L17TPT2/ref=as_li_qf_asin_il_tl?ie=UTF8&tag=shinyfastandl-20&creative=9325&linkCode=as2&creativeASIN=B01L17TPT2&linkId=3a23a7212d758f6228bab65e25003af0
Bosch K-Jetronic Explained (video)
https://www.youtube.com/watch?v=a4fJAfXYxWk
K-Jetronic quick-reference troubleshooting guide:
http://www.cabby-info.com/images/FuelSystem/CIStroubleshooting.jpg
Addtional information:
http://www.cabby-info.com/fuel.htm