3.6 cis revisited

[RJM3]

Is the cis on early 90's 3.6 turbo engines the same in usa market vs. euro version or are they like 3.3 turbo's of the late 80's with both a euro head and usa version ? thanks jer

[rattlsnak]

Well for starters the 3.6 turbo does not have CIS, it is Motronic. The '91-93 C2T's are 3.3's with CIS but much different than the pre 89 models. As far as I can tell, looking at the part numbers the fuel heads are the same.

[beepbeep]

That's what i told him but i got corrected.

3.6 cis

Can someone bring clarity into this? I have hard time believing that Porsche would put such crappy injection on such modern engine.

[ChrisBennet]

The 1994 "Turbo 3.6" had K Jetronic (CIS). Probably the last car built in the world using CIS. Ruf had Motronic turbo's back in '87 I think so there isn't much excuse for Porsche not having it. Hard to believe but true.
-Chris

[RJM3]

Chris do you know if it is the same cis used on the 3.3 turbo..what color is the head ? Is it possible for you to see a part no. on the fuel head..??thanks regards jer

[ChrisBennet]

Originally posted by RJM3
Chris do you know if it is the same cis used on the 3.3 turbo..what color is the head ? Is it possible for you to see a part no. on the fuel head..??thanks regards jer

Jer,
My "knowledge" of the '94 Turbo is limited to seeing a friend's original window sticker. I was amazed to see "K Jetronic" in the description and I remembered it for that reason.
-Chris

[Superman]

"crappy injection" huh? Smile when you say that, pardner!

Looks like some people are second guessing the engineering behind probably the most revered and respected supercars of all time. There are thousands of CIS Porsche turbos out there still kicking butts on streets and tracks around the world. There is also a pretty impressive string of endurance race victories (which I saw in my daughter's Guiness Book of World Records a couple of days ago) to criticize if you are still inclined to regard CIS as "crappy."

Reliability is another (important) question. I have never replaced the DME relay on my '83 SC, and it has been my experience that a "k-basic" system that gets clean fuel has an excellent chance at a MILLION MILES of trouble-free motoring. Or more. Who knows?!

I'm not trying to pick a fight. There are reasons why those idiots in Stuttgart made this decision. In fact, K-Basic CIS is probably the simplest and most reliable fuel system I have ever seen. Motronic gets last place in that measure.

[KTL]

Here's where I got my info:



The highlighted part is a injector valve for a K-Jetronic/CIS injection system. M30.69 is the motor designation for the 91,92 Turbo 3.3L



M64.50 is the motor designation for the 94 Turbo 3.6L motor



Here's a look at the rest of the intake system:



That intake manifold (shared by both motors) is that of a K-Jetronic/CIS system. Also, the two motors share the same CIS fuel distributor (not shown, tired of posting pictures) but use different air flow sensors beneath the distributor.

I don't own one, but i'm pretty sure the 964 Turbo 3.6 is a CIS puppy!

Please correct me if i'm wrong!

[ChrisBennet]

While I agree that CIS is an ingenious and reliable design I suspect Porsche's reasons for retaining CIS so long had more to do with economics than engineering.
-Chris

[rattlsnak]

OOPS!! I stand corrected,. what I meant to say was the 3.6 TT, is motronic,. not the 3.6 C2, which of course was 95, not 94.