Vader

For anyone who has even been unfortunate enough to work with a Bosch mechanical FI system, what is your opinion of the CIS and CIS-E systems? Personally, I feel they are a fornicating piece of excrement, substandard in design in almost every possible way. The only thing worse might be a CIE-E that leaked...

How does one go about adjusting standing fuel pressure on one of these POS? I've already dinked with the shim washers between the air vane control valve and base, and the POS car already has a new fuel pump, so that's not an issue.

This lame-āss thing makes me ashamed to be of German descent...

ede

don't hold back vader how do you really feel?

Vader

Geez, Ede. I was hoping You might have had some experience in these. You, or some of the other "old timers". I was just a bit frustrated after following the manual's procedures and screwing with that thing for two days to get the FP up to the top end of the spec. A neighbor had converted a Scirocco 16V 1.8L to a 2.0L bottom end, and it's obviously starving for fuel from about 5,800 RPM up. Pump volume is great, and dead-head pressure is over 100 PSIG. I just can't get the regulator to maintain the 81 PSI at the upper end of the factory "75-81" specification.

In exchange for being a "nice guy", I got a stark reminder os why I don't like Volkswagens. While Bosch was building a very well-designed EFI (TPI) system for GM in 1984, Volkswagen choose to use this POS mechanical injection system all the way through 1989, with bimetallic temperature compensation, mechanical vane air sensor to regulate injector pump stroke, "by-guess or by-gosh" fuel calibrations, and other special features that qualify it as excrement. How friggin' cheap could they get? I guess the German "engineering" isn't as phenomenal as some might believe. Thsi thing isn't even as good as the old Rochester RamJet FI systems from the early '60s.

Anybody have any pointers? I really don't want to log into a VW tech site if I don't have to...

ede

friend of mine has a vw deisel and i've been lucky enough to not get involved with it, other than soem consulting and i can honestly say i don't know a damn thing about it and don't want to. he did tell me for some reason after running mobil1 in it it dumped a lot of oil in the cylinders to be burnt. looked like a smoke screen behined him. switched back to rotella and no mokre problems.

forgot what i really wanted to say and had to come back and edit. is the regulator bad? seems like it must have an internal leak if it isn't holding correct preasure settings. how about bigger injectors for more volumn, but that wouldn't really help with a preasure problem.

Vader

It's running at 74 PSIG right now - just below the minimum spec. The injectors are remote, somewhat like the CPI systems. Like diesel injectors, they have a check/pressure valve that must have a given minimum pressure to open/spray. Apparently, about 70 is the minimum, since it wouldn't get fuel at all at 68 PSIG. If I only had a little magnesium...

ede

does it have a mechanical injector pump like diesels do? could you put the pump cover on a lapping table and try to remove a little bit, or have it surfaced , like .0005 -.0015 range, if it's anything like an oil pump that would increase your FP. really wish one of the experts would jump in here and help you but it looks liek all you've got so far is a dumbass from ohio

Jokerman

I had a 78 bmw 320i with the vacum CIS system. Not bad for the age, fairly reliable if maintained and serviced properly but if not you are seriously screwed. I had to have my 4cyl overhauled and when the guys at the shop we take our cars to put it in they apparently couldn't get the cold start setup to work properly and the intake boot was also cracked but they didn't seem to care or notice. Anyway i go on my marry way and 4 months later i have found a mechanic that knows bosch cis systems inside and out. He fixes the cold start and replaces the boot and some other odds and ends. Well shortly after i have a crack in my exaust manifold. Come to find out it had been there for a while and was part of the reason i kept haveing exaust gaskets slip. The car had apparently run so lean for so long with the cold start crap ****ed up that the manifold was glowing red as i was going down the road. So i replaced it and go on my marry way again. All fine and dandy until i see white smoke out the back end a few months later. The exaust manifold had cracked between the 2and 3rd cylinder, my aluminum head cracked between the 2nd and 3rd cylinder in three spots. the car is not junk. So if the system is not put together or maintained properly it can cost alot more than the $100 it might cost to have it checked out.

IROCmonkey

I have had some experiance with the CIS/CIS-E working on early 80s VW Bunny...basically the system is a PITA, couldnt get it to idle or lean out, had to borrow a Bosch manual to figure out that some jacka** had completely removed all the idle air controls!!

BTW You might want to try strolling into a nearby Borders or Barnes and Noble bookstore, whenever I have a perplexing problem I go plop my butt down in front of the auto manuals and do some research, its better than the library!

Vader

Thanks for the replies. It's an '88 Scirocco 16V with the CIS-E. Two local VW/Audi dealerships have given up in the car since it has the 2.0L case. A local VW privateer/guru that owns his own shop (where the dealer guys go when they're perplexed) doesn't have time to tear into it. I've spoken with him and he says the Bosch line regulators aren't adjustable, so you have to try new ones until you get one with a "good" spring. Really well-engineered, eh? I've looked at trying to convert to an adjustable type, but after talking to him have decided to take another route to enrichment and change injectors.

The air horn/boot is good. The idle and WOT switches are good. The differential pressure regualtor is good, the cold start and IAC work fine. I just don't want this guy to toast a head from running lean, like Jokerman did on his 320i. The main reason for the lean condition is the increase in displacement. I've looked at an ash-wiping Chilton manual, Bentley manuals and a Bosch CIS manual (but not the CIS-E). I guess he'll have to buy one for me.

I would like to see this dude get into a better vehicle, like a EFI car, but I hate to have something mechanical beat me. I've hammered on him as much as possible, stating that he doesn't need to change his banner around since I'm getting a lot of experience reading the "Neuspeed" labels backward (in the mirror), but he won't take the hint. Poor bastard...

Drkhrse89

iTrader: (1)

Vader if I remember correctly you live in my old home town. One place to check if you havent already done so is a place called *****'s it is off of Harrison IIRC (been a few years since I lived there) they worked on my moms Audi when she owned it and they were really good. That is about the best help that I can be since I know nothing of what you are talking about.