87 TR Coldstart Injectors no power

Finally started to "try" and track down my cold starting problem. But I was stumped almost from the start....pun intended. There is no voltage at the cold start injectors when the engine is cranking over. I swapped around some of the relays and they are fine. All the fuses are fine too. I unplugged and replugged all the connections I could...and looked for any loose ones. All appears okay. I have recently replaced both O2s sensors, the thermo-time switch, and the temp sensor. Do the cold start valves and the auxiliary air valves get their power from the same source? I thought about jumping 12 volts to the injectors just to see if they worked, but am worried about damaging something. Not sure where to look next...wiring is not my strong point...especially automotive wiring....especially ITALIAN wiring. Any help is appreciated. Thank You to ALL.

Hi Jeff,

The cold start injectors are turned on and off by the thermo-time switch.

You could turn on the fuel pumps and apply 12V directly to the injectors, and see if they work.......I have done this with no problem.

(Message edited by henryk on May 10, 2005)

Thanks Hank...as I recall the thermo-time switch keeps the inectors energized until a certain temp is reached. I installed a new thermo switch about a week ago just in the hopes that it was the problem....NOPE ! So I guess I need to track down the wiring to/from the thermo switch, and maybe look at the connection at the switch itself. To check for voltage I simply inserted voltmeter probes into the injector connector and cranked the motor. Is this correct? Is it possible to have the connectors to the temp sensor and thermo switch "swapped"?

I will check my car for the color of connector to each. I will report in a few minutes.

The front connector is brown (water temp switch), and the the one behind it is black (TTS). The front meaning the front of the engine.

BTW: I have the wiring diagram for the 87 TR, to help you further.

(Message edited by henryk on May 10, 2005)

Good News and Bad....the connectors were switched! So excitedly I swapped them with high hopes...but no change. I get only a few hundredths of a volt reading while cranking the engine. Darn it!

Thank You Hank....I guess it's back to square one.

Instead of starting the engine all the time, I would disconnect the safety circuit bypass......that way you could do all your voltage tests with just the ignition on. This is where I would begin......at take it from there.

Do you mean "connect" instead of "disconnect" ? By "bypass" you mean jumper wires used to enable the fuel and ignition circuits as shown in the shop manual? I will look into it Henry....I have some reading and studying to do. How are things in your neck of the woods?

Jeff,

he means "disconnect"!

pull the blue connector on the side of the FD. This turns on the entire system with the key, instead of making the engine run.

One "disconnects" the circuit (which protects the fuel pumps from going on with only the ignition, and not the starting motion), by "connecting" the bypass wires, as stated in the manual. It sounds strange, but makes sense.

The TTS gives power to the injectors via the "Starting injectors control relay". This recieves power from the + side of fuse #21........this is the 4th fuse from the very right......counting from right to left. Check to see if you have 12V there, with ignition on. If so, we can go further.

I am wiring up lights, fans and outlets in my new garage. The lift will go in last.