1986 560 CES cold start

[smokydave]

I have a 1986 560 CES with no cold start action. the problem is that there is no reference voltage going to the Coolent sensor or the fuel pump relay.Where does the voltage originate ( the cis-e module) ? I have checked all the relays and the wiring from sensor to the Cis-e and all are good. some one has replaced the coolent sensor the fuel pump relay and the cis-e controler/ without the voltage at coolent sensor and fuel pump relay there is no signal to the cold start injector. my question is has any one run into this? is it just a bad cis-e module or is there something i am missing about the origin of this reference 5 volt signal/?????

[pawoSD]

Is the Over Voltage Protection relay (black or red top with a door and fuses under it) good or has it been replaced?

[smokydave]

yes the fuse is good and the relay is new .so is the pump relay and the cis*e controler I have checked the wiring from the cis-e and the fuel pump relay and to the coollent sensor and both are good with no short to ground or short to battery + I am wondering about a resistor I see in the wiring diag it is called a ref resistor what is its function and can it cause loss of voltage to the pump relay and coolent sensor? Thanking you in advance for any help you can give me.

[Frank Reiner]

Does the engine run at all? Can it be started with fuel introduced through the air meter, or with starting fluid through the air meter?
If yes, we can proceed with the cold start valve problem.
If no, more basic analysis is in order.

When the key is turned to "on" (not start), can the fuel pumps be heard to run briefly (two seconds)?