CIS works only then starter is on

[karpis]

Hi,

please help with any ideas for this issue.
My 1980 911 with CIS was working fine before I removed and reinstalled air box. In process I removed throttle body and fuel distributor. After reassembly CIS is not supplying fuel to injectors while ignition is on and air plate is lifted. The fuel appears only then starter motor is engaged. I checked air plate switch and connector on fuel distributor and it seems to function ok.

Then I was experimenting with all connections near engine I found that if I disconnect a white connector with 2 red and brown wires, under rear fuse box cover, fuel starts to flow and can be controlled by lifting/lowering air plate.

I’m suspect this to be an electrical problem, but can’t figure out what is disconnected or not working.

Thank you for your suggestions.

[Jim Sims]

Check to see if you have switched the connectors for the air flow switch and CSV. Here's a section from a previous reply on the topic:


However, if you are connecting the wiring harness plug for the air flow switch to the cold start valve (CSV) instead of the air flow switch, the cold start valve circuitry will ground the circuit, energize the relay coil and cut power to the fuel pump(s). The connector for the air flow switch is higher up and just below the fuel distributor on the front (car's front) of the CIS system; the wiring harness plug that attaches to the airflow switch should be painted green or have a green dot on it. The CSV is down lower on the front side of the CIS system and it's wiring harness connector should be painted blue or have a blue dot on it. If these two connectors are correctly installed then check the air flow switch to see if it has continuity across the terminals. Put a VOM (voltage ohm meter) or powered 12 volt test light across the terminals and lift the air flow meter arm; if there is continuity when you lift the arm then there is a problem with the switch.

[karpis]

Thank you Jim, switched connectors was the cause of my problems.