Cold start valve on my '74 novice question

steve meltzer · 04-30-2019, 07:25 AM

The cold start valve is really a 7th injector, right? However, it doesn't look at all like the one in a shop manual my friend emailed me. Here's a picture of what I think is the cold start solenoid, at the arrow in my photo. I'd like to test it, but want to be sure i've got the right part! The white dots indicate the hot terminal with the key "on" (not start).
Comments? Thanx for indulging my ignorance. steve

mike fitz · mike fitz's Garage

I don’t think that’s the cold start mine is bit further back....maybe I’m wrong....mine is a 75

mike fitz · mike fitz's Garage

Just checked mine and it’s at the back of the air box....

manbridge 74 · 04-30-2019, 09:49 AM

Get a mirror and keep going. Not there yet...

mike fitz · mike fitz's Garage

. The two screw holes is the cold start valve on my car it’s at the back of the air box I had a backfire last week and had to replace this box Hope this helps .......mike

boyt911sc · boyt911sc's Garage

Below is the picture of the CSV for a 73.5 CIS. It is the black fuel injector with two (2) pin connectors mounted at the lower back side of the airbox.

Hope the picture helps.

Tony

steve meltzer · 04-30-2019, 10:32 AM

OMG those pictures and advice were fantastic!! thanx so much. looks like it will be hard to access. does the box have to be removed? thanx again, so very helpful. steve

boyt911sc · boyt911sc's Garage

Quote:

Originally Posted by steve meltzer

OMG those pictures and advice were fantastic!! thanx so much. looks like it will be hard to access. does the box have to be removed? thanx again, so very helpful. steve

Steve,

Use a small mirror to locate the two (2) Allen bolts that secure the CSV to the airbox. If my memory serves me right, you will need a 4-mm Allen wrench. Another tip: Attach a long string to the Allen wrench in case you drop it while removing the bolts. You could easily recover the Allen wrench by pulling the string up.

Tony

steve meltzer · 04-30-2019, 11:51 AM

Tony, thanx for the tips, tho' i'm highly insulted that you'd think that i'd drop a small thing like a 4mm Allen Key! Jeez! (now where did that M4 nut go??) s

john walker's workshop · 04-30-2019, 12:18 PM

The CS valve only works when the throttle is open enough to close the switch in your 1st picture, then only on cold start until the thermo-time switch warms up. adjust your hand throttle so when it's up, the switch is closed.

steve meltzer · 04-30-2019, 09:20 PM

Tony, thanx again for the pictures and info. I hope you know that I was joking about the "butterfingers"....all 10 in my case! I found the CSV and it looks like you can only take the first retaining hex head, then, let the CSV rotate before you can see the second one. Is this correct?

John Walker, are you saying that the switch shown in my first photo is the "thermo time switch" and should be closed when the hand throttle is up, just before turning the ignition key to the start position? thanx again. s

93nav · 10:19 PM

The thermo-time-switch is shown in the first pic in the thread below. It is in the left chain cover, close to the distributor. You should be able to see it real easy (I do not know if this is true for all years/models).

Thermotime Resistance Testing

steve meltzer · 05-01-2019, 05:35 AM

93nav, that's what i thought. So, what is the little microswitch that I pointed out in my first post? thanx again. steve

93nav · 09:26 PM

Here is that switch in the PET. All it says is 'microswitch'. I have no clue. In your pci, what is that screw above the microswitch attached to?

The microswitch is only valid up to 1975. Is it associated with the manual hand throttle lever (or whatever it is called) between the seats?

steve meltzer · 05-02-2019, 05:28 AM

93nav, thanx again for your interest..much appreciated. here's a better picture of that fully-threaded screw that appears to me, to acuate the ?? bimetallic strip. not sure how this is involved (if at all) with the hand throttle, but last nite, with the key on, moving the hand throttle, did NOT cause any movement in that microswitch. thanx steve

93nav · 05-02-2019, 01:40 PM

Steve, Re-reading the thread, see John Walker's comment in post #9.

steve meltzer · 05-02-2019, 01:48 PM

let me make sure I got this. my switch appears to be closed no matter position the hand throttle is in. now, maybe the switch is open when the car is warmed up, which would make sense, and i'll check this. And yes, John's comment was most helpful as were yours. thanx. steve

eastbay · 05-02-2019, 02:33 PM

You need to set the hand lever to the proper cold idle speed in the tunnel, then check that the switch is contacting when the lever is up. All in the manual.

steve meltzer · 05-02-2019, 04:11 PM

93nav, as a novice here, where do i find PET manual? The exploded diagrams would be invaluable. thanx steve

boyt911sc · boyt911sc's Garage

Quote:

Originally Posted by steve meltzer

Tony, thanx again for the pictures and info. I hope you know that I was joking about the "butterfingers"....all 10 in my case! I found the CSV and it looks like you can only take the first retaining hex head, then, let the CSV rotate before you can see the second one. Is this correct?

Steve,

NO. The CSV is an electro-mechanical fuel injector. The picture below shows a typical CIS CSV used in 911. To answer your question, you need to remove both Allen bolts (fasteners) to be able to remove or rotate the CSV.

Tony