CIS troubleshooting guide

Google Porsche 911 cis primer...

Same system, Bosch. Same components. Go on a Porsche site like pelicanparts and they have threads walking you through it...

 

^What he said. The best advice is from boyt911sc on the 911 Technical Forum. He is a CIS guru. Step one is always “buy a set of gauges and check your system and control pressures”.

 

Harborfreight makes a great gauge set for about 60$. You need to remove the schrader valves to make it work... it's all on the Porsche sites...

 

Link?

 

I know nothing!

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https://www.harborfreight.com/master-fuel-injection-pressure-test-kit-63727.html

Mine came in a red case. Reviews seem all over the place. I think the key is you must remove the schrader valves. I never had any problems with mine. Use the 20% off coupon...

 

Ta

 

Cool! Thanks for posting. Unfortunately, there is only one #$%#& symptom ("idle speed cannot be adjusted" = bad AAV) which does not have multiple causes!!!

 

Hence the need for the gauges to help understand what is actually going on with the system.

 

You might want to pick up a copy of this too.

https://www.ebay.com/p/Bosch-Fuel-Injection-and-Engine-Management-Handbook-by-Charles-O-Probst-1989-Paperback/813046?iid=292829133204&chn=ps

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