Randy V

I've got a problem with the CIS fuel distributor on my '79 auto, whereby the internal plunger tends to stick at the bottom end of its travel. This results in a dead spot between 1000-2500 RPM where the engine runs rough due to improper fuel metering.

And it's getting worse.

I have had my entire fuel system refurbished and this continues to be the weak link in achieving smooth acceleration performance.

Any suggestions for a source of a replacement CIS fuel distributor? 928 International lists a rebuilt one for $650, or a used one for $350 - both pricey options for a component that was widely used by numerous car makers in the early Bosch CIS fuel management systems.

Any and all feedback on this is welcome. Thanks.

John Struthers

Randy,
Bummer. And yeah, that is steep. I know guy's parting out 1980, 1988, and a 1991.
But I think the CIS went adios with the 79'.
The Portia site I mentioned in the 'leather'topic had several 928's and some parts/cars.give em a try and isn't there a 'SKBros' out of New Jersey that posts now and again? They said they buy/sell and part 928's and regularly have engines for sale. If you have the bucks and a great big set of brass one's - the wife - that whole 91' is, allegedly, going for $5500.00 -was in a wreak.
Good luck.
John S. & Pattycakes

Steve Cattaneo

Randy,

K-Jetronic systems are bolted to everything from Ferraris to rabbits.

The most comparable car to your 928 would be a Benz of the same year (v8). Try searching the web for CIS parts. Use the casting number on the distributor, not the 928 numbers, when searching for the parts.

Just a thought…

Good Luck
Steve C
The Great White

Jim Nowak

Randy,

I just happen to have a complete top-end off my '79, complete CIS and extrued honed induction, because I'm switching to the Electromotive engine management. I could not use any of the parts in the conversion process.

Contact me off list if your interested.

Jim Nowak

Randy V

Thanks for your insights John and Steve.

Jim, you have mail!

Max

Randy, With the Mr. Injection's handy dandy CIS training video! You too, could be a CIS mechanic in just a few short hours! And if you call in the next 10 seconds we will also include the all inclusive CIS for dumbies 3 page booklet for the low, low price and 3 easy payments of 19.95

All kidding aside,
If you have the work instructions on how to set-up the sensor plate and the CO, why don't you first try taking the Control cylinder and plunger out and clean it up. Most of the time the plunger will get a varnish build up on it that just needs to be poilshed out.
My first Porsche (78 924) had this same problem. Every 6 months or maybe longer if I did a good polishing job on the plunger, I would take the whole thing apart clean it and put it back together and every thing would work great for a while. It's just the nature of the beast (CIS beast). After you get the Sensor plate off, look to see if any of the pivet points have worn and check pins for wear/flat spots.
After you do it two or three times you'll see it's no big deal. I had it down to about two hours for the R&R, this included my typical Union breaks and soak time.

If you need info E-mail me off list and I'll look it up for you.

Cheers

Max

Randy V

Good stuff there Max, thanks.

The root problem with mine however, is that the plunger body has some scoring that results in it's 'notchy' performance.


Previous attempts at cleaning/buffing resulted in only a maginal improvement.

Max

Well, sounds like it's time for a good used fuel distributer or rebuild yours.

Many years ago you could get a rebuild kit for the Fuel distributer which included new Control cylinder and plunger, O-rings, spring and a few other things. I was able to get mine from a place call WAWD but I don't think they are around any more. Now I think World Pac has kind of taken over where they left off.

Here's the link. Keep in mind that this is for registered WP parts dealers only. I think you can at least find out through them if they offer a kit,get the part number then order it from a WP retailer.

<a href="http://www.worldpac.com/" target="_blank">http://www.worldpac.com/</a>


HTH

Max

Randy V

More good stuff from Max - gracias muchacho.

I thought those could be rebuilt, but my mechanic was not in agreement.

The search is on for a rebuild kit!

Jim V

Max,

THanks for the link to worldpac, turns out there's a dealer local to me... cool.
A quick search of their catalog shows they carry
quite a few 928 parts..well worth checking out.

JimV

Max

All,

Whats on their web sit is just a fraction of what they have in stock or can get.

Just for grins, after I posted the link, I looked up Randy's needed Kit. They show that they have one. You just can't tell what comes in it.

Cheers

Max

Dennis Wilson

Randy,

Have you checked the plate to make sure it isn't off center and binding? Also, will the plate pivot without binding with the fuel distributor head/plunger off? If those are free the problem is as you suspected. Since the plunger and cylinder are mated they both will have to be replaced together. There is a short article in Up-Fixin volume V, page 117 on rebuilding the CIS distributor. It has some good information, except the recommendation to use loctite 242.

Good luck,

Dennis

Randy V

Dennis, yes the plate (I assume you mean the air metering plate) is centered and not binding.

'Replacing the plunger/cylinder' and 'except to use Loctite 242' - could you clarify these two?

Dennis Wilson

Randy,

If you are going to get a kit to rebuild the distributor, make sure it has a new plunger and cylinder as they are factory matched for tolerance. concerning the loctite 242, the Up-Fixin article says to use it to seal the steel gasket between the two halves of the distributor. I tried using it, but it kept plugging the small openings between the top and bottom. I ended up using an old rebuilders trick of coating both sides of the gasket with axle grease instead. Hasn't leaked or blocked any passages. BTW have you checked your control pressure to make sure it isn't too high and causing your hitch?

Dennis

Randy V

Hey Dennis, thanks for the additional info - I'll keep that in mind if/when I rebuild mine.

Fuel control pressure checks out within spec limits.