Cold Start Valve Access and Troubleshooting?

[NoYouRelax]

After much research and troubleshooting, I think I've pinned down an indle issue and gas mileage issue to a leaking cold start valve, on my '83 SC 3.0. I want to check it to see if it leaks when it is supposed to be closed, but accessibility looks tough. I am thinking a partial drop might be enough. I also have to check the temp switch to verify it is operating properly.

Has anyone done this task and is it easier done with a partial drop?

[timmy2]

If you have a pop off valve installed just jumper the fuel pump to run and look inside. Once the system pressure hits it, it will leak and you will know if it is spraying fuel.
No drop needed if you have a pop off and can look into the box.

[NoYouRelax]

Thanks! I have the pop off and that sounds like the plan. Now I have to start searching for my fuel jumper I devised last year.

[timmy2]

Lol, always fun finding stuff you made a year ago. Someday I will put my jumper in a logical place, for now it sits in the electrical junk drawer of my toolbox...
Once you determine if the injector is ok or not, then move on to the thermal switch.
Functional test of the switch on the car is a pain as you need to disconnect the yellow solenoid wire(s) at the starter so the car won't try to start as you energize the circuit to see if the injector sprays when it should.
Cold Start Injector circuit is only energized when the key is turned to start.

[boyt911sc]

Originally Posted by NoYouRelax

After much research and troubleshooting, I think I've pinned down an indle issue and gas mileage issue to a leaking cold start valve, on my '83 SC 3.0. I want to check it to see if it leaks when it is supposed to be closed, but accessibility looks tough. I am thinking a partial drop might be enough. I also have to check the temp switch to verify it is operating properly.

Has anyone done this task and is it easier done with a partial drop?

Bill,

The first time I did the removal and re-installation of the CSV was just removing the CIS 'pope' rubber boot only in the mid '90's engine in situ and never knew a forum like this existed. Anyway, you probably bruise your arms without an engine partial drop. To test the CSV for leak and operation with the engine installed, you need something like this:





What this hose does is bring the CSV out in front of the engine instead of sitting behind the motor. Then you could pressure test the CSV by running the FP and observe for leak or dripping. And you also test the spray pattern of the CSV safely in a glass jar or transparent vessel during its operation.

The TTS (thermotime switch) is very easy to test. Keep us posted.

Tony

[boyt911sc]

Originally Posted by timmy2

If you have a pop off valve installed just jumper the fuel pump to run and look inside. Once the system pressure hits it, it will leak and you will know if it is spraying fuel.
No drop needed if you have a pop off and can look into the box.

Bill,

You have a late SC with the spider injection plumbing in your CIS air box. The CSV won't be visible through the pop-off valve even if you have a probe scope or X-ray vision. Even removing the throttle body won't help. Unless you have the old stock air box from the '76-'77 CIS (without spider plumbing).

Why do you think I made this fuel hose to test the CSV for air boxes with spider plumbing?



Tony

[timmy2]

Bill,
Unfortunately Tony is correct as usual, the later cold start plumbing will impede your ability to see if the CSV is spraying or leaking.
I guess a partial drop and rigging up a testing apparatus is the only way to do it. Sorry, sometimes the older ones without improvements are easier...
Teating the thermal switch requires a different method with the CSV out. Pull it and test with a meter as has been discussed in other threads.

[NoYouRelax]

Tony....you win the Dr. Gadget Prize already in 2014. Congrats!!
Great to hear from you too. I have a spare CIS set up where I can rob a CSV fitting and start my testing. I can deal with the bruises, I just hate losing skin off the knuckles and watch that clear oozing stuff mix with grease and fuel.

If it ever gets warm out, I will visit you.

Timmy.....thanks for the input and the good ideas around charging the circuit. I might be able to borrow a fiber optic scope at work and snake it into the pop-off valve to confirm leaks.

Thanks guys!

[Bob Kontak]

PET says that in 1981 there was an airbox change. Not sure if it had to do with the internal baffles though. I know on my 81, I have no view through the pop off valve hole. See number 9.