83 SC fuel injector inspection and performance

[sjheinz]

83sc. Checking spray pattern and seals on injectors with 120k miles. Injector seal (green) replaced on injector.

Took out #2 and the "socket or Offically the INJECTOR SLEEVE" came out with the injector. I appears that there is a rubber O ring seal at the top of the socket, but it is so hardened that it appears to be plastic. [B]Answer: o ring at top hardens and needs to be replaced. If the Injector Sleeve came out with Injector it should be replaced as well. Not expensive.[/B]

Is there an o ring on the injector socket, (also heard it called a bung, but it officially a Injector Sleeve if you go to look for one) that should also be replaced (knife points to suspected o ring) ? find it here Porsche 911 & Turbo CIS Fuel Injection - Page 5 http://www.pelicanparts.com/cgi-bin/smart/more_info.cgi?pn=911-110-886-03-M260&catalog_description=Injector%20Sleeve%2C%20%20%39% 31%31%20%28%31%39%37%34%2D%38%33%29%20

How to best remove the sleeve if if doesn't come out with the injector?

Should the injector MIST or spray (as a faucet sprayer)? ANSWER:a v shaped mist

If it sprays (as in my case) will serious dose of sea foam clean these up?

Danke.

[Scott R]

Yes, replace the "hardened" o-ring on the injector bung. In fact just order new bungs as well if you're going to do all six since they sometimes break on removal.

Two ways to do this, find something that fits in the bung to use as an extractor. Or pull the CIS, remove the runners and pop them out. There are some tiny metal stakes keeping them in, but as you found out they don't really hold them very well. Use a little grease to slip them back in.

[sjheinz]

Thanks Greg,
Kinda what I was thinking.
Where might I get the "bunge"?

[sjheinz]

83sc. Checking spray pattern and seals on injectors with 120k miles. Injector seal (green) replaced on injector.

Took out #2 and the "socket" came out with the injector. I appears that there is a rubber O ring seal at the top of the socket, but it is so hardened that it appears to be plastic.

Is there an o ring on the injector socket that should also be replaced (knife points to suspected o ring) ? Scott repliesYes, replace the "hardened" o-ring on the injector bung. In fact just order new bungs as well if you're going to do all six since they sometimes break on removal.

How to best remove the socket if if doesn't come out with the injector? Scott replies Yes, replace the "hardened" o-ring on the injector bung. In fact just order new bungs as well if you're going to do all six since they sometimes break on removal.

Should the injector MIST or spray (as a faucet sprayer)?

If it sprays (as in my case) will serious dose of sea foam clean these up?

Still looking for answer on injector spray pattern. thanks.

[boyt911sc]

The spray pattern should look like a V-shape in mist form. If the fuel flow comes out as jet of stream (fuel), it is no good. Plus it should not drip at standby. Another important parameter you have to check is the opening pressure. Ideally, All six (6) plus the 7th injector (CSV) should have similar or close opening pressures. I arbitrarily segregate my CIS fuel injectors into different group numbers like:
Group I: 35 - 40 psi.
Group II: 41 - 45 psi.
Group III: 46 - 50+psi

Some criteria are uniform mist spray pattern, opening pressure, and no drip at standby. These are my personal preference and I stay away from using GROUP III.

Tony

[timmy2]

Originally Posted by sjheinz

Thanks Greg,
Kinda what I was thinking.
Where might I get the "bunge"?

Injector sleeve and o-ring here:

Porsche 911 & Turbo CIS Fuel Injection - Page 5