Cant find the cold start valve

[brett25]

I can find where the CSV is located. Could anyone point me in the right direction?The photo in the Bentley guide isn't much help. Thanks very much

1980 911 SC

[crustychief]

Behind the filter housing, almost in the center of the engine compartment.

[crustychief]

Look in the Bentley on page 200-3, the line from number nine is almost touching it.

[brett25]

ok, thanks crustychief, so you have to reach around and feel for it? Is it possible to replace this with the engine in the car?

[crustychief]

It can be done with the engine in the car with a mirror and patience.

[Peter Zimmermann]

Originally Posted by brett25

ok, thanks crustychief, so you have to reach around and feel for it? Is it possible to replace this with the engine in the car?

Brett, just curious, why do you want to replace it?

[brett25]

well im thinking I might have to. My symptoms are very difficult cold start. Once the car is started, everything else is normal. Warm/hot starts are normal. In the morning it takes alot of cranking to turn over. Do you think it may be something else?

[scotricker]

It is located way back behind the engine, way down in there in the back. I have never seen mine yet... but I didn't look too hard either, I guess.

But I did check the Thermo-Time-Switch that is right there in plain view on the driver side cam cover. The TTS (search for it) was faulty, so I replaced it with a used one that I got from a fellow Pelican on the parts for sale forum.

That might be something to diagnose, too.

[arbita1]

Honestly, I was never really able to locate it until I removed my engine. Oh...so that's where it is. If you're going to replace it, it will be by feel mostly. Maybe a partial engine drop would help.

However, before getting into that I would recommend testing the wiring and temp sensor that controls the cold start valve first. They are much easier to get to as well.

Always start with the easy things first.

[boyt911sc]

Originally Posted by brett25

I can find where the CSV is located. Could anyone point me in the right direction?The photo in the Bentley guide isn't much help. Thanks very much

1980 911 SC

Brett,

This picture will show you where the CSV is located. I could removed and install the CSV without any partial drop because my fore arms are small and skinny. Most individual would have problem reaching it and could results to bruises and cuts without a partial engine drop. The clearance between the top of the engine bay and the engine is quite tight. At the lower right side of the picture (below) with a bluish plug and connector just below the throttle housing is the CSV. HTH.



Tony

[brett25]

thanks for your replies.

scotricker, thanks. I read your post at length, so did your issue turn out to be the TTS? The thread dropped off. I believe yours tested bad? Did that fix your issue.


boyt911sc, thanks for that excellent photo. I can feel the CVS and its somewhat reachable for me as I no longer have any of the engincompartment padding so there's a bit more room. I read your helpful replies to scotricker's thread, and this helped me alot as well.

Since my issue is purely a cold start issue (hard to start when cold) I am assuming that it is the CVS/TTS circuit. AM I correct in this theory.

I have purchase a used replacement TTS for starters and will test this tomorrow, before dealing with the CVS

thanks again everyone

[boyt911sc]

Originally Posted by brett25

thanks for your replies.

scotricker, thanks. I read your post at length, so did your issue turn out to be the TTS? The thread dropped off. I believe yours tested bad? Did that fix your issue.


boyt911sc, thanks for that excellent photo. I can feel the CVS and its somewhat reachable for me as I no longer have any of the engincompartment padding so there's a bit more room. I read your helpful replies to scotricker's thread, and this helped me alot as well.

Since my issue is purely a cold start issue (hard to start when cold) I am assuming that it is the CVS/TTS circuit. AM I correct in this theory.

I have purchase a used replacement TTS for starters and will test this tomorrow, before dealing with the CVS

thanks again everyone

Brett,

Get the CSV off the engine by using an allen wrench attached to a long string. Chances are that you'll drop it during removal. And to retrieve the fallen wrench would take so much effort and time or luck to locate it. Do not disconnect the fuel hose and electrical plug because you'll need that for your test. Plus you cannot removed the electrical plug without getting the wire clip off. You'll know what I'm talking about when you do the job.

Place the disconnected CSV with the fuel hose and electrical plug still connected into a suitable glass container and start the engine (CDI/ignition disconnected). Two things you have to check:
1). Does the CSV get power (during cranking)?
2). Does the CSV injects fuel (during cranking)?

The TTS (thermotime switch) is grounded (closed) when the engine temperature is below 113°F and open above this temperature. Note: This is the engine temperature not ambient temp. Keep us posted.

Tony

[brett25]

hi tony,

hopefully it will have been the TTS, but im gearing up for the CVS.

one question, I heard it was possible to see the CSV squirting fuel with the unit still installed (perhaps through the throttle body) also what the size of the allen wrench?

thanks

[brett25]

well,after replacing the TTS with a used replacement, as well as installing a new battery, the car fired right up this morning. It was a bit warmer this morning, so Im not 100% sure yet, but it could very well have been the issue. I will post again if status changes. thnaks for your help and interest

[Bob Kontak]

Originally Posted by boyt911sc

Get the CSV off the engine by using an allen wrench attached to a long string.

Ha - how smart is that?

I loosened mine and I am pretty big. Scuffed up my forearms plenty but no partial drop and I have metal fuel lines. I pulled it back out one or two inches, set up a video camera and a good light and turned the key. Let me know it was working.

[scotricker]

Brett, I just checked back, and it looks like you are doing well.