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-   -   It's that time of the year AGAIN! (CIS) (http://forums.pelicanparts.com/showthread.php?t=185926)

Paulporsche 05-29-2007 05:28 AM

Gunter has given you a test for the CSV. You can try that and let us know the results. As a general rule, however, if the engine starts, then the CSV is working, although there are variables, such as the length of firing and whether it is leaking.

Your symptoms sound to me more like your AAR is not operating correctly, but it is at least working. Check out mystery train's thread on AAR repair.

I am thinking your WUR is not operating correctly. I can't remember, have you checked your fuel pressures? I think your control pressure may be off, and your mixture setting may also be set slightly off.

The photo shows the later style AAR which is not adjustable per se, as Gunter said. There is a fix for it however, which involves removing it and squeezing it in a vice tom reduce its dimension by 1 mm. This "adjusts" it into the correct config. You may want to replace it w/ another, maybe earlier, one from a wrecker, or remove it as many have.

EDIT: Sorry, above paragraph refers to Decel Valve not AAR

T77911S 05-29-2007 12:17 PM

someone else had a question about the firing voltage of the CSV ( this is not related to the problem). but if you take out the CSV, try firing it with a 9v battery. someone else said theirs fired at around 10v and didnt know if that was correct or not.

you can use a hand vacuum pump on the decel valve. i believe mine opened around 20in. ?? you should not be able to blow through the big fittings with it closed.

+1 on what gunter said about it working great, it is also reliable and yes simple compared to carbs, only 1 adjustment on CIS, plus a LOT better gas mileage. i am getting 20+ and i have it set rich. dont get me wrong, i love the sound and performance of carbs, i just cant afford them and i have a good CIS system if the FD ever goes bad, hello carbs.
learn CIS, its not that hard once you understand what role each part plays.

my money is still on the AAV and/or the plumbing to it and the AAR.

if the car is lean due to an air leak, lifting the sensor plate compensates for the air leak.

favrok01 05-30-2007 10:23 AM

MY problem was fixed by the adjustment of the AAV. Thank you Paulporsche & Gunter. It does go down quicker but not as fast as i am used to. it is turned all the way down.
i think i will do a parts swap with another CIS i have and see if its just a "old" AAV or if its just sticky.

MotoSook 10-24-2007 07:04 PM

here you go Jeff.

http://forums.pelicanparts.com/uploa...1193280955.gif

sand_man 10-21-2008 05:34 AM

Giving this the annual:
http://forums.pelicanparts.com/uploa...1224595981.jpg
(BUMP)

For all the CIS NOOBs that might be wondering what's going on, now that the temps are dropping...

MotoSook 10-21-2008 06:52 AM

Nice bump :D Ouch...

It was 40 degrees during my commute this morning. I'm sure some CIS engines out there were doing some hunting to start out their morning.

GothingNC 10-21-2008 07:42 AM

No difference with my start at 39 degrees yesterday morning.

1st turn of key without idle hunting.

sand_man 10-21-2008 08:07 AM

Quote:

Originally Posted by GothingNC (Post 4251651)
No difference with my start at 39 degrees yesterday morning.

1st turn of key without idle hunting.

Yeah, same for me. Started as soon as the key was touched and needed very little help with the idle (I removed my AAR long ago). However, things smell a tad rich for me, in the cool weather. I'll be checking my pressures and checking AFRs with my LM1, just to be sure.

P Moore 10-21-2008 01:57 PM

Been doing lots of reading here..
OK, i imported my 1975 targa from Arizona in june this year and i believe the car had not been started in about a year or so.
I have rebuilt the whole car, interior, paint, seals etc....no rust.
When it came to the engine i only gave it a clean up and replaced the rocker seals and the rubber rings on the inlet manifolds, also i noticed that the plunger thing on the fuel distributor was stuck but this was sorted with some carb cleaner and then i was able to move it up & down freely, - Sorted I think ??
When it came to starting the car for the first time after all this it started very very first turn !!
i could'nt beleive it that it started so easy, but it seems to be running very very rich, blackish smoke and i know by the smell of it !! also idling high, It takes throttle no prob and its very responsive
These are my thoughts.....
The Cold Start Valve is staying open, is this possible ????
The WUR is faulty....Any way of testing this ?? i have no way to carry out a pressure test...
Also over here in Ireland we use 95 octane but i dont think this would have a big affect....
Previously on the forum i had some issues about the connections to the WUR/CSV/ etc. so im hoping these are ok.
The Decel valve was disconnected when i got it so i have left it like this.......

Over here in Ireland there is not many experts for these motors, and i have to say id be lost without this forum...

Paulporsche 10-21-2008 02:08 PM

PMoore,

I would suggest you start a new thread w/ this post.

You will prpbably get more responses and ones that are specific to your problem.

BTW you probably should get a CIS fuel pressure gauge which is helpful in tracking down CIS problems. And check your mixture so that you have a baseline, especially if you think it is running rich. JW recommends 3.5% which is about 13.1 or .2 to 1 AFR.

coolngroovy 10-21-2008 07:30 PM

Quick Q,
This CIS fuel pressure gauge you gentlemen are refering to, is that a designated part? or will any fuel pressure gauge do the job?
Cheers, Col.

MotoSook 10-22-2008 07:32 AM

Any guage that has a 0-100 psig range will work, but it isn't just the gauge. One needs the correct connectors/fettings, lines and a valve to isolate the system pressure when testing.

911 tweaks 10-22-2008 10:45 AM

does pelican offer a tool to test cis??

brads911sc 11-08-2008 07:19 PM

CIS Question
 
There is a vacuum part over by the Oil Fill tube, right above the spark plugs, that has two big hoses going into the back of it and a vacuum line coming out the front... The vacuum hose is quite long and goes over to the driver side of the engine bay. Question... what does this vacuum line get connected to? I was doing a clutch job and this got disconnected and I have no idea where it goes... The pics Ive seen seem to show it connected to the throttle body... thanks...

Gunter 11-09-2008 07:29 AM

Quote:

Originally Posted by brads911sc (Post 4291388)
There is a vacuum part over by the Oil Fill tube, right above the spark plugs, that has two big hoses going into the back of it and a vacuum line coming out the front... The vacuum hose is quite long and goes over to the driver side of the engine bay. Question... what does this vacuum line get connected to? I was doing a clutch job and this got disconnected and I have no idea where it goes... The pics Ive seen seem to show it connected to the throttle body... thanks...

Stating the year/type wouldn't hurt.

I assume it's a later SC with Lambda and you're describing the Deceleration Valve The small vac line goes to the back of the TB right next to the vac advance connection for the distributor.
There are several small connection nipples; pick one and plug any open ones.

MotoSook 10-07-2010 11:02 PM

Just saw a few threads on CIS that appear to be weather related....

wesayso 11-12-2016 02:51 AM

A very old thread, yet I have visited it regularly. Winter is a bit late here this year...
Each fall I have to turn my mixture screw 1/8 turn CW, each spring I dial it back again.
(sometimes I need a small adjustment for our version of the MOT, resetting it to where it was after that)
This thread together with http://forums.pelicanparts.com/porsche-911-technical-forum/232089-cis-idle-speed-mixture-setting-without-analyzer.html has kept me sane driving my CIS car all year round.

Thanks for this valuable information, Souk!

MotoSook 11-12-2016 06:30 AM

Talk about a way back machine ;)

My last post on this thread is about as old as my youngest born. I'm glad folks still find this stuff useful. I haven't touched a CIS car in years...probably couldn't find the mixture screw ;)

Keep the CIS alive boys!

Souk

wesayso 11-12-2016 06:34 AM

Hahaha, I've been driving this car for 11 years now and I've visited both of your CIS threads multiple times. It's about time I said: thank you :D.

Porschephanatic 11-12-2016 02:46 PM

I forgot about this thread. I'm glad I subscribed in '04. I still adjust twice a year. I keep the allen wrench in my glovebox, and it works every time! LONG LIVE CIS! :D


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