Hi Guys,

My 928gt (1991) manual tends to stall when the aircon is on. This is occurs more when the vehicle is cold. Any ideas?

Another question I have is, what is the optimum running temp of the 928?

Regards,

Theunis

 

What is the maintenance on the intake and ignition systems?

The temp. needle is typically in the middle of the lower and upper while lines but again maintenance will have a big bearing.

 

The idle stabilizer valve is what sets the idle speed as directed by the computer. It often gets sticky some have used lubricant spray into one of the camcover breather hoses that enters the intake BELOW the mass air sensor to free it up. Should that not work replacing it requires removing the entire intake manifold and when in there several other things like hoses, knock sensors, gaskets, many refinish the intake as well.

 

Thanks for the quick replies guys.

@Malcolm: I got this vehicle only a week ago, but it has a comprehensive service history with porsche since new until now. It has 137000km on the odo currently.

@James: Thanks for the advice. I will try the lubricant spray first. Moving on to your other suggestions should that fail.

Thanks again.

Regards

Theunis

 

hopefully the Porsche techs know their 928s......did they refresh the intake?

 

Theunis,

I don't remember the mileage readings on the metric setting - sorry.

Change the info read-out to instant fuel mileage. Get on the open road where you can keep the RPM level over 1800 RPM. With the engine speed over 1800 RPM, lift your foot completely off the throttle and let the car coast. The mileage read-out should go to a max value and stay there until the RPM level drops below 1400 RPM, where it should be at a high, but slightly lower reading. Repeat, but this time, while the mileage reading is at max, just slightly press down on the throttle. The mileage read-out should drop to a slightly lower level.

The reason for this test is to quickly and easily show you whether or not the throttle idle switch is functional. If it is not, the ISV doesn't know that it should hold the idle speed...

 

The digi dash display l/100km so the lesser the number the better.

 

I am going to have to check the records to make sure, offhand I cannot say if they refreshed the intake.

 

Thanks Wally, I will give it a shot!