no power to the cold start injector time switch
12-20-2015, 01:29 PM
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no power to the cold start injector time switch
I have a problem with my 95 3.0 4Runner not wanting to start well when cold.
I pulled the cold start injector and tested it with 12 volts and it opens and sprays fine.
I then checked the cold start time/thermo switch and it measures about 81 ohms
when engine is warm. Looking at the wiring diagrams there is a green wire and
a blk/yellow wire going to the time switch and the cold start injector.
When I jump the connectors at the time/thermo switch I do get power to the green
wire at the cold start injector with ign switch to cranking. When I tested the cold start
injector wires first thing in the morning at 30 degs temp, no power to the green wire
at the cold start injector. So this would be a bad cold start injector time switch if I understand this?
I pulled the cold start injector and tested it with 12 volts and it opens and sprays fine.
I then checked the cold start time/thermo switch and it measures about 81 ohms
when engine is warm. Looking at the wiring diagrams there is a green wire and
a blk/yellow wire going to the time switch and the cold start injector.
When I jump the connectors at the time/thermo switch I do get power to the green
wire at the cold start injector with ign switch to cranking. When I tested the cold start
injector wires first thing in the morning at 30 degs temp, no power to the green wire
at the cold start injector. So this would be a bad cold start injector time switch if I understand this?
Last edited by 67lotus49; 12-20-2015 at 04:08 PM.
12-20-2015, 10:06 PM
#2
If you find it hard to figure things out when they're right in front of you, it's harder for us. Why don't you post that wiring diagram so we can help better?
12-21-2015, 06:45 AM
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Could be.
Your resistance measurement is within spec. http://web.archive.org/web/201411140...ne/97colds.pdf But that just tells you the internal heater is not shorted/open. To open the CSI, the time switch shorts the STJ (Green) line to ground. Therefore, there should NEVER be "power" to the Green line, rather with key to start the B-W line to the CSI gets 12v (which is grounded through the STJ line when cool).
I would pull the solenoid connector (small wire) to the starter so I'm not dodging the fan while testing. I would disconnect the CSI injector, and a) look for ground on the green wire, and b) 12v on the B-W with key to start. If you don't have ground on the green wire I would suspect the time switch.
Note that jumping the connectors on the Time switch is "backwards"; you're connecting the 12v (at start) B-W line to the Green line. The Green line is supposed to go to ground to fire the CSI, not to 12v. If you had the time switch connected when you jumped the terminals, you would have put 12v straight to ground and blew up the starter relay. Try to be more careful with your jumping.
Last, my EWD shows the other wire to both the CSI and the time switch as B-W, not B-Y. But 20 years can do that.
Your resistance measurement is within spec. http://web.archive.org/web/201411140...ne/97colds.pdf But that just tells you the internal heater is not shorted/open. To open the CSI, the time switch shorts the STJ (Green) line to ground. Therefore, there should NEVER be "power" to the Green line, rather with key to start the B-W line to the CSI gets 12v (which is grounded through the STJ line when cool).
I would pull the solenoid connector (small wire) to the starter so I'm not dodging the fan while testing. I would disconnect the CSI injector, and a) look for ground on the green wire, and b) 12v on the B-W with key to start. If you don't have ground on the green wire I would suspect the time switch.
Note that jumping the connectors on the Time switch is "backwards"; you're connecting the 12v (at start) B-W line to the Green line. The Green line is supposed to go to ground to fire the CSI, not to 12v. If you had the time switch connected when you jumped the terminals, you would have put 12v straight to ground and blew up the starter relay. Try to be more careful with your jumping.
Last, my EWD shows the other wire to both the CSI and the time switch as B-W, not B-Y. But 20 years can do that.
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