It's that time of the year AGAIN! (CIS) - Page 5

ruf-porsche · ruf-porsche's Garage

Even though my garage queen sits most of the time, whenever I go to start her she always starts and normally on the first or second try, no matter what the outside temperature is.

But then I also have a stock a/c system that is capable of blowing 32 degree vent temp in the summer.

JBO · 10-28-2005, 05:19 PM

Harry- there is actually a category #4, for those like Souk and Paul, and of course John Walker, who have tinkered with CIS enough to be able to adjust it by sound/feel. I hope to be there one day

MotoSook · 03:48 AM

limble..yep..like Ianc said, re-install the pop-off valve and go from there.

My CIS 3.0 sat for over 4 months and after a little purging and priming of the fuel delivery...it fired right up and idled just fine.

Here's something that should be kept in mind:

The CIS is not a carb. I've been told by folks that they pump the throttle before starting and during cranking. Pumping the throttle prior to cranking does nothing. There is no accelerator circuit or pump like a carb, and when you pump during cranking (with a moderately well tuned CIS) you are actually going to cause leaning and popping of the blow-off valve.....Don't pump during cranking. If you need to do that, there are other issues that need to be addressed...like maybe a too rich setting or unhealthy cold start.

All adjustments are to be performed with the engine at operating temperate.

tbitz · 10-28-2005, 08:04 PM

Quote:

Originally posted by HarryD
I saw this a while back and was saving it for a thread like this:

The world is divided into three types of CIS Owners, which one is you?

1) The guys with working CIS systems out driving their cars so they won't reply.
2) The guys that tinker with their CIS systems and have them royally screwed up and keep you running in circles with suggestions.
3) The guys that have spent a fortune on Webers, PMOs, EFI etc will tell you they're great to justify their expenditure to themselves.

Your choice.

I fall in catagory #3, but object to the cost being a fortune. EFI conversion is $1599, not sure if you consider that a fortune? It's the same as what a CIS fuel distributor would cost.

My EFI conversion does run great. This time of year the temperature in Canada is below freezing and the car starts on the first crank, and I drive away within 5 seconds after startup.

Cheers,

HarryD · 10-28-2005, 08:11 PM

Quote:

Originally posted by tbitz
I fall in catagory #3, but object to the cost being a fortune. EFI conversion is $1599, not sure if you consider that a fortune? It's the same as what a CIS fuel distributor would cost.

My EFI conversion does run great. This time of year the temperature in Canada is below freezing and the car starts on the first crank, and I drive away within 5 seconds after startup.

Cheers,

OK Tony, the parts are $1,500. As you note, not a bad deal. If my CIS system needed major surgery (it does not, runs great and I leave it alone), you WOULD be on the short list of options.

How much time to install and tune? Do I need any special tools or other equipment if I am working at home?

tbitz · 10-28-2005, 08:17 PM

Harry,

Folks have installed the kit in one day. No special tools needed. Comes with a base configuration already programmed. Some fine tuning maybe required.

Email me off line for more details. I don't want to hijack this thread.

Cheers,

MotoSook · 10-29-2005, 04:04 AM

Lets not start any rumors or scare folks. CIS is misunderstood enough

. There are plenty of serviceable used parts on the market. And if not advertised, a WTB ad will have CIS parts coming at you faster than a WTB Fuchs ad. A new $1500 fuel distributer is a poor purchase if one has a bad distributor. There are used distributors that have sold for less than $300 and there are rebuilders out there. Hell, I picked up a whole CIS for less than $300.

Again, I'm not saying CIS is the ONLY way to go. EFI is great (some ofyou know I've got a "commercial interest" in EFI kits), but sometimes a $300 fix is better than a $1500 fix+tuning on a dyno or country road.

OK! Back on topic

During cold fall or winter starting, the engine will sometimes pop if I tip in on the throttle before the engine has had a few monutes to idle. If the car has started and it's idling (higher than idle speed)...leave it be. The warm up will happen as it should...racing the engine won't make the car warm up that much quicker. Some of the behavior that folks adapted when they owned carbureted cars is not always applicable for non-carbureted cars

I suspect a lot of blown airboxes happened due to an impatient owner. If you are popping at tip in when the engine has warmed up...you may be running lean.

HarryD · 10-29-2005, 10:44 AM

Souk,

Thanks for weighting in here. IMHO, for those of us who are mostly interested in a nice street ride with ok throttle resposne, good fuel mileage and am willing to leave the last 10% of the cars potential performace on the table, I am not sure much beats a well tuned CIS system for simplicity and ease of operation.

I will stand on record as a fellow who has and likes his CIS Car. But as you note, it is important to have a guy locally who understands them and will not let me waste his time or my money fishing for problems.

randywebb · 10-29-2005, 11:38 AM

re scary rumors -- I am joking or (halfway anyway). If you already have CIS and want good cold starts (with some risk) and don't want to spend a lot of $$, then leave it on there. It will cost a lot to change it. Also, you can do the work yourself - the basic trouble-shooting procedure is to replace various parts of the system until you find the one that was broken - each component will run a $100 or a few 100 so it can add up. But you will then have new components...

CIS was economical and gave good emissions performance - it was the best solution to those problems back in the 70s. It is simpler than EFI also. The throttle response is lacking so to me it is good for your mom's Volvo, less good for a 911. A collateral benfit is that CIS makes a fine whipping boy...

sammyg2 · 10-29-2005, 12:04 PM

My CIS works great, no starting problems cold or hot. It is also basically maintenance free. No seasonal adjustments necessary, my O2 sensor does it for me.
I am a confirmed CIS lover.
besides, with what other fuel injection system can you increase the power 50 to 75% by just bolting on a small modification to the intake and exhaust?
CIS rules

Of course I have to do some "maintenance" every other year, for smog reasons

ianc · 10-29-2005, 02:03 PM

Quote:

the basic trouble-shooting procedure is to replace various parts of the system until you find the one that was broken - each component will run a $100 or a few 100 so it can add up.

No, that is how one troubleshoots carbs. CIS is much easier than that.

ianc

MotoSook · 10-29-2005, 06:20 PM

Randy, that is also the behavior of an uneducated (CIS) owner/wrench. That's like say (and I'M half way joking

) you replace the engine if the starter is dead (and you don't know it's the starter.

randywebb · 11:11 AM

Yes, well there are a lot of uneducated shops...

Also, IIRC, don't some tests require instuments that most private owners don't have?

I'll admit to another bias - carbs were the thing when I grew up, so I am used to them... Not that I haven't screwed around with CIS on 2 911s, and a Saab...

limble · 10-30-2005, 05:56 AM

She rocks, she rolls!

I epoxied the pop-off valve back in, waited 24 hours for the epoxy to set. Started it right up. I'll richen it out a little later today.

I'm going to park it in the heated garage for cold mornings. The overnight is 30 but day temps get up to 60.

The other car has 40 TIN zenith carbs. So the CIS is much less finicky.
I'm not bashing Zeniths, they're just different, so please don't flame me.

Thanks to all for the advice.

conrad_bookout · 01-05-2006, 05:47 PM

I cannot get my 3mm allen wrench to mate up with the "female" hex head on the mixture adjustment screw on my '77-S with CIS K-Jetronics. Any ideas? Could it be dirt in the head? If so, what's the best way to clean? Thanks!

MotoSook · 01-05-2006, 06:03 PM

I assume you can get it in the hole of the housing, but the wrench won't go in, right?

JBO · 01-06-2006, 06:33 AM

It takes a lot of patience, particularly the first time - like putting in contact lenses the first few times. Sometimes it helps to remove the air box cover and push up slightly on the lever while inserting the allen key.

Paulporsche · 01-06-2006, 07:07 AM

Conrad,

There may be dirt in the slot. You can try a wire (say from a coathanger) to clean it out. Some use compressed air. Or you could try inserting the Allen wrench and dripping a small amount of WD40 or penetrating oil down the shaft.

Afterward, keep it clean down there by plugging the hole w/ the factory plug w/ the loop on top or some other suitable, removable plug.

Macel · 06-14-2006, 12:49 PM

If I start the thing up, and am getting lots of sweet smelling smoke and the engine runs really rough/wants to stall, am I running too rich?

MotoSook · 06-14-2006, 01:16 PM

You have to be a little more descriptive. Start a new thread and give as much details as you can. "Sweet smelling" smoke can mean anything (e.g. that is a bakery truck went just as you started the car.)

Did you read the threads to understand enough to ask questions? I'm sorry to be so candid, but beating around the bush and soft selling won't fix the engine and we'll spend more time quessing than actually solving the problem. As I have said before, you don't go into the doctor's office and complain about a pain on your body, then shrug when he ask where on your body, right?

Now think what the situation would be like if your doctor is online and you are describing that pain on your body, but can't give any more info than that. It'd be tough for the the best doctor in the world to help you, right?