s928s

I have just started the rbuild process on my 1982 euro 928 with CIS. I have a few questions to start with the CIS system.

1. has anyone ever converted the hard lines to stainless braided lines ?
2.Can I or should I rebuild the CIS distributor? If so where would I get the parts and how difficult is it ?
3. Is there any perfomance mods to enhance the CIS.
4. Is it better to replace with a EFI system.

..thanks in advance, DAVID

GlenL

1 - Not that I've heard of. (Why?)
2 - Possibly. The o-rings inside it get hard and the plunger can get gummed-up. (Search)
3 - Not really "mods" but tuning the mixture rich/lean is super easy.
4 - That'd be a lot of work and money. It works great when it's working great.

John Veninger

1. Why convert?
2. The CIS distributor can be rebuild but many don't since it requires precision and keeping everything very clean
3. There are minor ones, but on a stock car there is no need. My non-stock motor still runs stock CIS
4. How much money do you want to spend?

Most of the issues with CIS is dirt. Check the screen going into the fuel distributor and also the screen in the warm-up regulator. They some times get clogged up.

s928s

Thanks for the input..I was concidering the braided lines as a cosmetic upgrade, but I am sure I can utilize the current lines. is there a rebuild part number for the "o" rings, and is it worth it. I an not having any drivability issues...I am not looking to spend money hat is not cost or h/p effective.
thanks again, DAVID

John Veninger

Then leave the CIS alone.

Dennis Wilson

David,

Bosch and Porsche considered their fuel distributors to be factory rebuild only, so no part numbers are published. Actually the adage "if it ain't broke, don't fix it" really applies to the distributor. I have ran a 924 with over 300K miles and the distributor didn't miss a beat. The worst thing you can do to one is let it sit for an extended period with fuel in the system. When the o rings do go, they will normally dump too much fuel to the injectors. Rebuilding instructions (abbreviated) can be found in the PCA's Up Fixin V. There are 4 surfaces, 8 orifaces, 8 valves with springs and 10 o rings involved. I found the correct size o rings at the local auto parts store. Just make sure they are the fuel resistant type. As John V stated, the surfaces must be super clean and flat. The cylinder and piston must be clean, undamaged and unhoned otherwise it will leak like a sieve. Needless to say everthing has VERY close tolerances. That is why dirt or fuel additive accumulation can kill the system.

Dennis

tammons

I have just started the rbuild process on my 1982 euro 928 with CIS. I have a few questions to start with the CIS system.

1. has anyone ever converted the hard lines to stainless braided lines ?

Possibly, but it would be difficult

2.Can I or should I rebuild the CIS distributor? If so where would I get the parts and how difficult is it ?

Its not that complicated. I had mine apart, but from what i understand its tough to get it right. Probably best to get a rebuilt one.

3. Is there any perfomance mods to enhance the CIS.

Doubt it unless you go a euro high compression engine.

4. Is it better to replace with a EFI system.

IMO yes. I had so many CIS problems I bailed. Went to a tec III but it is expensive. Also I was turbocharging my car and the CIS system was too limiting and the rebuilt distributor was $850 anyway.


..thanks in advance, DAVID

checkmate1996

I thought that RICH99P(sp?) rebuilds these and has had very good reports...

GlenL

There's a pdf out there (looked, didn't find) on how to do this. Good pictures and descriptions.

This is not something to do a preventative maintenance. Besides, removing the fuel distributor is about a half-hour job.

Do clean the screen at the inlet that John mentioned. It's part of what looks like an adapter on the body of the fuel distributor.