Help Locating Cold Start Valve '89 930

[blichjr]

For the life of me I can't seem to find the location of the cold start valve on my '89 930. I believe it is the K-Jetronic II, but I'm not 100% sure. The throttle body casting part number is 930 110 180 3R. Here is a photo with the intercooler removed. I am assuming it is on the back side of that casting (toward the top of the picture) but I can't see it. Does the K-Jetronic II not use a CSV? I scoured through the parts PDF and didn't find one. I did find the thermo switch on the LH Cam cover. Any help much appreciated!

body

[HaroldMHedge]

I think you have to remove the air cleaner 930.110.020.01 and then you can see it under the back side of the throttle body.

See K-Jetronic I page 56, Item 44, 930 606 107 01, electronic starting valve of this PET.

911 USA 87-89 Katalog

Harold
87 Carrera Coupe

[T77911S]

its in the back under everything. you cant see it.
remove the air cleaner.
on the front of the fuel dist you will have 2 fuel lines coming off the front. the right one goes to the WUR, the one to the left of it goes to the CSV.
the line runs down and under the Afm bowl to the back of the intake manifold.

its not really that easy to get off with the engine out.
why do you want to find it. they don't usually go bad.

[blichjr]

I'm having trouble on hot start sometimes where she won't fire up. I come back after a couple hours and she starts - a little rough running for a bit, but after a couple minutes runs fine. I wanted to test the CSV and the thermo time switch. And now it just won't start at all.

Thanks Harold - I looked back there with a mirror and didn't see it. And the funny thing is that it isn't shown in the parts manual. Check out P. 59. Again, mine looks like a K-Jetronic II, not the I. On the I it definitely shows it located exactly where you mention.

I'll pull the air cleaner off tonight and have a look again.

[blichjr]

OK - I took a closer look and see that the intake manifold appears to be the same for the K-Jetronic I and II and the throttle body is just different. I should be able to locate it once I get the air cleaner off. But holy crap - could they make those two screws on the top any more difficult to install?

[blichjr]

I found it! But it is in a most inconvenient location. Are there any tricks to remove the CSV to test it, or do I actually need to remove the complete mixture control assembly including the lower housing?

[T77911S]

told you it was a witch. I would not pull it out for your problem.
verify the 2 wires are on the TTS.

the CSV has nothing to do with hot starts. that could be residual fuel pressure and/or the check valve at the fuel pump.

here are some things you can do first. I like to do easy stuff before I jump into something hard or spend $$
make sure the FP's are running.
locate the connector on the top rear of the AFM and remove it.
remove both FP relays up front,
turn the key on
put in one relay and verify you hear a pump. don't leave it running long. remove relay.
put in other relay to verify other pump.
turn off and put relays back.

turn key on
on top of the AFM there is a spring load mixture adjustment thingy. yea I said thingy.
push that down and that will put some fuel into the engine. don't do it but a few seconds.
its best to do it while someone else cranks but you can do it by yourself.
this will simulate the CSV circuit.
the IC needs to be back on but you can leave the air cleaner off for this.

did you verify spark.

does the frequency valve vibrate with the key on

[blichjr]

Thanks for the suggestions! I'll run through that list. My thought on the thermo switch was from the CIS troubleshooting guide. If the switch is failed closed it'll cause hot-start issues. If failed open it'll cause cold start issues. The hot start was fairly intermittent. But the cold start is something new. I can get a volt meter on the thermo switch and have someone crank the engine to verify (CIS disconnected of course) that. I'll also work through the other steps you've mentioned. Good to hear the CSV's are reliable - any failure history on the TTS? Oh, and what is the frequency valve? Sorry - kind of a newbie on this engine. By the way, I use thingy regularly ;-)

[T77911S]

I don't know how often the TTS fails. I think its pretty rare.
thing is, the problem you describe has it failing BOTH ways, first closed then open.
not to say anything cant happen, just looking at the odds.

if you can get to your TTS then you are better off than I am. not sure I could get a meter on mine.
one side has power all the time. the other only when cranking.
I would probably use a test light and connect it to 12v at the fuse in the engine bay since the TTS is providing ground.
check both sides, light should light.
let it heat up and open up, then only one side should light the light.
never checked this, light may not be as bright as if grounded.

[HaroldMHedge]

Originally Posted by blichjr

I'm having trouble on hot start sometimes where she won't fire up. I come back after a couple hours and she starts - a little rough running for a bit, but after a couple minutes runs fine.

I agree with T77911S, your description describes a residual pressure problem so check the residual fuel pressure. Your pressures should be 1.6 bar after 10 minutes and 1.4 bar after 20 minutes.