CIS Tester Guage Instruction

[Thack]

Well, now I have my tester guage but I'm not sure where to hook it up. Does it fit inline between the WUR return line and the distributor? How do you get both control pressure readings and system pressure from just turning the valve on the guage?

Mike

[Jim Sims]

Installs in line between center of fuel distributor (FD) and WUR; gage is on side towards FD and valve is on side towards WUR.

Check cold control pressure with engine stone cold (as in sitting all night) and not running; pull fuel pump relay and jumper relay socket (between pins 30 - 87a) so the fuel pump runs. Valve is open (allows flow between WUR and gage). For 1979 through sys number 0 438 140 045: 25 psi@50F, 32 psi@75F,and 43 psi@100F; for '79 sys number 0 438 140 045 and after: 21 psi@ 50F, 33 psi@75F and 47psi@100F.

After checking cold control pressure check system pressure under same conditions (stone cold engine, engine not running and fuel pump running) but valve is closed. pressure should be 65 to 75 psi for '79.

Pull fuel pump jumper and replace relay; open valve. Start engine and allow to warm up, warm control pressure should be 39 to 45 psi once engine is warmed.

Shut off engine and leave valve in open position; rest pressure should remain at or above 16 psi for at least 20 minutes.

If all of this is confusing, may I suggest you purchase a fuel injection manual to go with you tester. It will guide you through troubleshooting. One good one is: "How to Tune and Modify Bosch Fuel Injection" by Ben Watson.

Jim

[Thack]

I understand completely . Thanks.

Mike