I have the old hard to start when cold problem. I am getting 2.4 ohms at injector and 32.4 ohms at start time switch. from what I have read this is in spec. But when I put the injector in a glass when cranking to check for fuel spray., I am getting nothing. Where would you guys go from here? what could I further test to find if its the CS injector or start time switch? An advise helps!

 

Dumb question 1 - what is a time swith? Having the same problems...

 

I believe its called start injector time switch. It sits below your thermostat housing. plug to left. should be brown. someone correct me if i am wrong but it is what sends the signal to the cold start injector on when and how much fuel to spray.

 

You are correct. The injector will only spray when the key is in the START position.

Try this: pull the plug off of the injector and put 12v to the pin that the black wire goes to and ground the other pin. The injector should spray when this happens. If not then the injector is bad(not very common) if this works then it is either the wiring or the time switch. There are some more tests you can do to pinpoint it.

 

looking a a diagram i have one wire on the time switch plug should get voltage when cranking, the other wire on time switch plug connects to a wire on the injector plug, and the other wire in the injector plug connects to ground

 

Did you find your problem?

 

Mine is doing the same,if it don't start the first time it won't start ? Floods with gas,I have been following this Thread in hope's someone could help PLEASE ,I am so fed up with it( DRIVING ME CRAZY) what does the cold start injector time switch look like ? I have a feeling this is the Gremlin that is giving me all my grieve,When my Toyota is running right it is such a pleasure to drive. I am new to the broad its a great place YOTATECH to meet and get advise,.I have put so much work into my 1987 Toyata 4 runner and I will not give up on my new project,Until i getting running good,it has been worth every penny,I have put in to it. It's Just got the color code Dark Grey cant want to paint it,I just found out it is the Deluxe Model from the Vin #.Lots of extras,I was hoping for a striaght axle "oh well" maybe next time ,I do know how hard it was for me to find this one.I Had to change out the auto hubs.Those were a nightmare I purchased a set of used Warn Hubs Prem's best thing I every did.good night and again any help..........

 

the time switch and the injector both get 12v when the ignition switch is in the START position.
The 12v in the time switch is for a heater element that heats the sensor up.

The time switch provides the ground for the injector if the water temp is cool enough. If it is warm then it does not complete the circuit and the injector cannot open.

If the water is cold then the heater element starts to warm the time switch so that after a certain amount of "time" the sensor stops providing the ground for the injector(thats what the wire connecting them is for)

I believe this is so that if for some unrelated reason the truck doesn't start, the cold start injector will not keep filling the intake up with fuel


Does that clarify things?

 

The time switch is just under the thottle body. There are two sensors side by side. The one on the left is the Time Switch, on the right is the Coolant Temp Sensor.

This will only cause problems in cooler weather. In my case it was about 35 deg or colder. Here's a link to my thread over on Mud. Post #18 has an FSM diagram on how to check it to see if it's good or not. HTH.

http://forum.ih8mud.com/79-95-toyota...ont-start.html

 

.....cold start injector time switch on left..coolant temp sensor on right.

 

My cold start valve is showing 3.2 ohms, coolant temp sensor is showing 7.5 ohms and it's about 23 degrees here. Switch is showing 40.0. Anyone know how to check the tvv?

 

I am drawing a blank, but what is the tvv? I have gotten one of my Cold Start Issues fixed by cleaning the build up on the Cold Start Injector Time Switch, just use a brass tooth brush to get it back down to bare metal. It can get a hard water build up on it.

 

The TVV is part of the EGR system, not sure if that's what you want. If you meant the VSV for the fuel system it's linked below. There's no way to test it that's mentioned though, or I couldn't find it.

http://personal.utulsa.edu/~nathan-b...36electron.pdf

The TVV is described in the section below:

http://personal.utulsa.edu/~nathan-b...18egrsyste.pdf

 

Thanks, Guys and especially mldave! Ruby Tuesday starts like a champ (sounds like "ta-da-Vroom!") when warm but takes some time in the cold morning, so I'm working on her cold start injector system this weekend.

 

Found the cold start timing switch here:


Close-Up:


Cleaned the contacts, I had not way of checking water temp but resistane between 2 terminals was 50 ohms. I think that's within spec.

When I located the Cold Start Injector, I found that this connector was not installed properly and that the wire lock was not in its place.


Checked the resistance between two terminals of the CSI and it is within spec. 3.6 ohms.

I suspect that last person who worked on it may have done that, or some dishonest mech may have done it in hope that owner would bring it back to his shop for repair- Easy money, huh?

Waited until Sunday AM to try and it works now.

However, noticed some sort of deposit (soot? overheated Oil?) where the CSI mounts.



What do you guys think? Fuel leaking from there? Or, Is there any kind if suction in throttle body, and it's sucking in oils vapors from the engine compartment?

Will investigate further.

 

Found the cold start timing switch here:


Close-Up:


Cleaned the contacts. I had no way of checking water temp but resistane between 2 terminals was 50 ohms. I think that's within spec.

When I located the Cold Start Injector, I found that this connector was not installed properly and that the wire lock was not in its place.


Checked the resistance between two terminals of the CSI and it is within spec. 3.6 ohms.

I suspect that last person who worked on it may have done that, or some dishonest mech may have done it in hope that owner would bring it back to his shop for repair- Easy money, huh?

Waited until Sunday AM to try and it works now.

However, noticed some sort of deposit where the CSI mounts.



What do you guys think? Soot? Overheated Oil? Fuel leaking from there? Or, Is there any kind if suction in throttle body, and it's sucking in oils vapors from the engine compartment?

Will investigate further.

 

Should probably just get a new gasket. Don't see what overheated oil would have to do with the intake. And yeah, of course there's suction in the throttle body. Could be carbon from emissions I suppose. Wipe your finger through it. Is it oily, or sooty like carbon? I would wipe it off after you feel it and replace the gasket so you can watch it. Probably nbd though.

 

Busted gasket. Notice that sides much closer than the rear to the mating surface. *shrug* could be egr goo or just someones greasy finger prints, fuel splash.

 

Tnx! Yeah, could be that someone tested it just right off the throttle body.

 

Great pics!!