Why does my Porsche 911 have a vacuum leak?
Any vacuum leaks will cause problems in regulating the mixture, and may also result in an uneven idle. To check for vacuum leaks, spray some carb cleaner or starting fluid around the hoses and injectors of the fuel injection system. If the engine idle increases, then you probably have a vacuum leak that needs to be tracked down.
Are there any problems with the Porsche 911 CIS?
Although the CIS has a reputation for reliability, it is also known for having a few characteristic problems. Warm and cold start problems are common, as well as backfiring and poor performance at startup. On the early 911s, the CIS didn’t even operate properly, until the car was warmed up.
Why does my Porsche 911 have a cold start?
Cold start problems can often be attributed to the thermo-time switch or the warm-up regulator. For more information than you will probably every need on the CIS, take a look at the book, “Bosch Fuel Injection & Engine Management” by Charles O. Probst.
When did Porsche 911 start using fuel injection?
In 1980, emissions requirements forced the introduction of an oxygen sensor into the system, which helped the engine to better run at the appropriate mixture level through the regulation of fuel pressure inside the fuel distributor. The two primary adjustments for the CIS are the idle speed and the mixture adjustment.
Any vacuum leaks will cause problems in regulating the mixture, and may also result in an uneven idle. To check for vacuum leaks, spray some carb cleaner or starting fluid around the hoses and injectors of the fuel injection system. If the engine idle increases, then you probably have a vacuum leak that needs to be tracked down.
Although the CIS has a reputation for reliability, it is also known for having a few characteristic problems. Warm and cold start problems are common, as well as backfiring and poor performance at startup. On the early 911s, the CIS didn’t even operate properly, until the car was warmed up.
How does the leak down test work on a pelican?
Set it to TDC for that cylinder, set the incoming pressure on the leakdown tester, attach it to the spark plug hole, and then read the difference on the second gauge. The difference will give you your % lost. Repeat on all the other cylinders.
What should the idle speed be on a Porsche 911?
The idle speed is adjusted by allowing more air to bypass the closed throttle. Using a large flathead screwdriver, simply rotate the screw clockwise to reduce the idle, and counter clockwise to increase it. The idle should be set to be about 950 rpm. So what can go wrong on with the CIS? Plenty.