checkmate1996

Folks,

I have two spark plugs (5 & 7) that are running lean. Where do I look first for troubleshooting? Should I clean/replace the fuel injector? Go right into the CIS head and start pulling apart?

I appreciate thoughts...

Brad

Dave928S

I'd get the injectors cleaned and flow tested first, before you even think about doing anything with the fuel distributor. Highly likely that you've got poor flow on those two ... and maybe others. It'll be money well spent no matter what.

checkmate1996

Dave,

Thanks for the response. After doing some digging around the internet, some other 928 owners have found success using a mercedes benz (part# 0437502047) fuel injector for $33 as direct replacement. I was thinking about just replacing them versus the cost of flow testing, etc. Thoughts?

GlenL

I did exactly that with the M-B parts and it worked great. They are a little shorter than the Porsche parts but fitted fine otherwise. $31 at Rock Auto.

The old sleeves and bushings are a pain. Plan to be down a while to get replacement parts or buy some in advance.

checkmate1996

I was thinking about buying the CIS removal tool from 928motorsports to help. Are there any special instructions on removing these things?

checkmate1996

As I am working on these injectors, is there an expectation that the silver aluminum sleeve and the rubber bushing are a one time use? Not intended for reuse?

rjm65

I went with the MB injectors about 2 years ago. I replaced all the rubber bushings, the old ones were hard as a rock. I lucked out as I did the job when 928Intl has their half off sale, ordered 8 used (new looking!) sleeves from them to have on hand. I think about half the injectors came out ok, the rest I had to use vice grips to loosen the sleeve.

jpitman2

I had little trouble remobing my injectors - get a deep socket (12mm?), fit over the injector end (pipe removed of course), and give a good sharp smack on the socket bar. The rubber grommet things were very hard, and it wasnt easy removing them, or fitting the new ones on the injectors - lube helps a lot. It seems to be relatively difficult in US the get these injectors tested and cleaned (cost me $100 the set of 8 here a few years ago), so I would just replace with the brass MB units - I have seen these as low as $21 now and again. The VERY LAST thing I would do is dive into the distributor head!.
jp 83 Euro S AT 54k

vze2jshn

Run some Techron through before anything else?

checkmate1996

I was really struggling with getting a visual on how to remove everything. I couldn't find any videos on youtube on pulling a 928 fuel injector and alot of other post descriptions were a bit cryptic. RMJS pointed me to a ferrari website and they definitely have some CIS gurus over there. One of their techs developed a nice 'extractor' of sorts...but he wanted $112 for it. Conceptually, I took the idea and ran with it ... I went to Lowe's and picked up the following goodies:

Parts: (Purchased from Lowe's for <$20)
3/4" x 24" Type L Copper Pipe $10
1/2-13x5 Hex tap Bolt Full Thread $2.37
1/2" Coupling Nut $4
1/2-13 Hex Nuts Grade 8 Qty 2 Pack $1
1/2"-13 Washer Qty 1
2 M10x60 Full Thread Hex Tap Bolts
2 M10 Washers
2 M10 Self Locking Nuts
PB Blaster

My objectives were:
Create/Describe easy way to pull the injector without leveraging valve covers, stripping hex openings and/or ruining any chance of re-using the injector.

Here's the tools I used:
Tools:
1/2" 12mm Allen Socket
1/2" Rachet
1/2" 19mm Socket
1/2" 13mm Deep Well Socket
10mm Allen Wrench
Medium Sized Vice Grips
Dead Blow Hammer
19mm Wrench
Drill w/ 5/16 & 11/16 Spade Bit

Replacement Part #s:
Sleeve - 928 110 399 02
Rubber Bushing - 928 110 398 00
Fuel Injector - 928 110 225 00 or
0437502047 (MB Part)

Process:
Before doing anything I generously sprayed down all the injectors with PB blaster and let it soak for about an hour.
While that was happening, I built a place on my bench to attach the spider and prep it for fuel injector removal.
Then I use my newly built tool and easily removed the injector.
The rubber bushings just popped out every time and the aluminum sleeves were salvaged.

Here's a quick video...let me know what you think! Thanks for all the feedback also. I'm now ready to tackle the job on the real motor!