CIS Injectors - a little help please?

uBoat Commander · 12-23-2013, 03:32 PM

I have two questions - I ask of the forum's collective expertise -

I have a 81 EURO 928S, 4.7L 300HP CIS engine.

1. Are the injectors the same as the 79 4.5L CIS cars? When I look up parts, I only find USA parts (that are not CIS at all for a 1981)

2. I took out the injectors, and the aluminum collar (from the intake spider) came out with it. It appears that the injectors almost, well, just pry out from this? Is that correct?

Thank you all in advance for sharing your knowledge

GuyS · 03:47 PM

There is a rubber seal that sits in the injector sleeve and the injector itself is pressed into the rubber seal. I believe the injectors are all the same for the CIS cars (part number 92811022500)

uBoat Commander · 12-23-2013, 03:42 PM

Thank you!

How do I dismantle without destroying everything? Injectors being replaced, how do I get it apart?

GuyS · 12-23-2013, 03:52 PM

If you have a vice, open it just enough to sit the sides of the injector sleeve on it. I then tap the injector straight down with a piece of wood. Doesn't take a lot of force, just a few light taps. A properly sized deep dish socket can also be used to support the sleeve. The old seals can be slit with a razor and removed or if still pliable, you can then pull them off the injector.

uBoat Commander · 12-23-2013, 03:58 PM

Thank you, gentleman!

It APPEARED that was the way to do it, but I get in the most trouble when I assume stuff.

GuyS · 12-23-2013, 04:04 PM

No sweat. While you have it apart. Check your mounts on the air meter assembly. they typically disintegrate and are cheap to replace while you are at it.

I just did this job along with a rebuilt fuel distributor. Makes a world of difference. Good luck!

uBoat Commander · 04:34 PM

As everything on the intake was originally "frozen" when I got it (flood damage) I planned on cleaning everything, cleaning screens, etc.

Corrosion inside is very bad - I have to remove & clean everything.

Injectors are simply balls of rust. Did the "CLR" dunk & sand, I see this on the side -

BOSCH (014)
0437 502 012

So, for future reference, Euro 928S from 1980-83 use the same CIS Injectors as from the 1979 CIS with the above part #

uBoat Commander · 12-23-2013, 04:44 PM

Quote:

Originally Posted by GuyS

No sweat. While you have it apart. Check your mounts on the air meter assembly. they typically disintegrate and are cheap to replace while you are at it.

I just did this job along with a rebuilt fuel distributor. Makes a world of difference. Good luck!

You mind if I ask - Where did you get a rebuilt fuel distributer? Or air meter mounts?

GuyS · 12-23-2013, 04:58 PM

I used a ultrasonic cleaner on mine. Worked well, mine still leak down a bit but I am hoping that resolves with use.

My FD came from a guy who sells on eBay under the name "rebuiltsystems". Great price and service. He even sent me some before and after pics. Rebuild is possible as DIY but for $159.00, my time was better spent elsewhere.

I have a wholesale account through my business so the dealer is always an option for my Porsche parts. In this case, Roger (928srus) supplied my vac lines, seals and mounts.

Mounts are part number 99970326100. They are cheap, around $3 each

This was the fuel assembly after rebuild, cleaning and installation.

AirtekHVAC · AirtekHVAC's Garage

There is a guy on eBay that will rebuild them very reasonable. (Like 150$) You can buy a kit for about 90$ and rebuild yourself....

I used Mercedes injectors...they are a bit shorter, but work great.

Mercedes Benz Brass Upgrade 8 Fuel Injectors CIS 85 92 Used Nice | eBay

uBoat Commander · 05:27 PM

********.com has these BOSCHE Injectors, new, $35 bucks a pop. Sold.

Saw the rebuild kits on eBay - I have two to rebuild, so SOLD.

Porsche 928 4 5 928 4 7 s Bosch Fuel Distributor Repair Kit 0438100027 | eBay

LOLOL - OK - Injector sitting on my desk. I'm an impulsive idiot, and I put it up to my mouth and blew into it.

Forget the fact that I just blew crap all over my computer screen, I assume I should not be able to blow thru it as easily as I can a straw?

GuyS · 12-23-2013, 05:31 PM

Just my .02

I love learning and tinkering. Love doing all my own work and rebuilding.

With that said, I have seen too many people attempt these FD rebuilds unsuccessfully. Sealing seems to be the trouble spot. For the extra $59.00, I left the labor to someone else with the experience.

Again, not being discouraging, just food for thought.

uBoat Commander · 12-23-2013, 05:35 PM

I'll agree - anyone have a link to the guy that does the rebuilds? I've searched eBay to no avail - I only found the kits

GuyS · 12-23-2013, 06:46 PM

Here ya go!

rebuiltsystems on eBay

I had mine back in under 10 days, no affiliation, just a happy customer

Danglerb · 12-23-2013, 07:24 PM

Rust in the injectors, makes me think rust or junk everywhere so everything that fuel touches should be cleaned or replaced otherwise junk is going to clog the new stuff.

uBoat Commander · 12-23-2013, 07:34 PM

I agree completely - So far the tank has been cleaned, new strainer, new pump, new filter, flushed lines.

I'll may just buy the rebuild kit for the fuel distributer (I would like to learn the insides), new injectors. Removing entire air system to polish, clean, lube.

GuyS · 12-24-2013, 04:22 AM

Quote:

Originally Posted by Danglerb

Rust in the injectors, makes me think rust or junk everywhere so everything that fuel touches should be cleaned or replaced otherwise junk is going to clog the new stuff.

Good advice of course. I wound up replacing everything except lines and injectors. I soaked the smaller lines in brake cleaner and used compressed air (100psi or more to blow them all out. I also blew out all the main lines as well.

Check your distribution banjo bolts for the small filter screens. Sometimes they get stuck in the bolts.