Can Aux air pump affect idle?
11-09-2020, 02:07 PM
#1
Burning Brakes
Thread Starter
Can Aux air pump affect idle?
Hi everyone!
Yesterday I noticed that aux air pump belt was breaking, I cut it, put in the bin and restarted engine.
1 the engine at idle is very quiet, so I need a new and a pump overhaul is due.
2 idle is so much smoother.
How air pump can affect idle? Maybe the diverte valve is not working properly? Vacuum hoses are new and I have lo leaks.
How to inspect diverter valve?
Any help is very appreciated
Francesco
92 gts 5 speed
Yesterday I noticed that aux air pump belt was breaking, I cut it, put in the bin and restarted engine.
1 the engine at idle is very quiet, so I need a new and a pump overhaul is due.
2 idle is so much smoother.
How air pump can affect idle? Maybe the diverte valve is not working properly? Vacuum hoses are new and I have lo leaks.
How to inspect diverter valve?
Any help is very appreciated
Francesco
92 gts 5 speed
Last edited by siscogts; 11-09-2020 at 02:08 PM.
11-09-2020, 02:27 PM
#2
Rennlist Member
The bearings can be bad, making noise, creating drag on the idle speed..
But otherwise it has zero effect on idle air or fuel flow to the engine.
It's output when cold goes to the cat, and when warm goes to the airbox as "fresh air".
But otherwise it has zero effect on idle air or fuel flow to the engine.
It's output when cold goes to the cat, and when warm goes to the airbox as "fresh air".
11-09-2020, 03:28 PM
#3
Burning Brakes
Thread Starter
Thank you!
I can move the pulley of the pump with zero effort,there is noise but no effort but at higher rpm I think there is some drag...
OK, I will remove and overhaul it...
It is not necessary to pass smog test, but I like the 928 in the original shape, with its pros and cons.
I can move the pulley of the pump with zero effort,there is noise but no effort but at higher rpm I think there is some drag...
OK, I will remove and overhaul it...
It is not necessary to pass smog test, but I like the 928 in the original shape, with its pros and cons.
11-09-2020, 03:33 PM
#4
Rennlist Member
Thank you!
I can move the pulley of the pump with zero effort,there is noise but no effort but at higher rpm I think there is some drag...
OK, I will remove and overhaul it...
It is not necessary to pass smog test, but I like the 928 in the original shape, with its pros and cons.
I can move the pulley of the pump with zero effort,there is noise but no effort but at higher rpm I think there is some drag...
OK, I will remove and overhaul it...
It is not necessary to pass smog test, but I like the 928 in the original shape, with its pros and cons.
It's worthwhile to have there to offset main bearing load from the alternator.
11-10-2020, 01:04 AM
#5
Burning Brakes
Thread Starter