Questioning the reliability of the 996 (starting problems) + Fuel Vent System(PICS)
06-30-2010, 10:32 PM
#106
That little fitting on the left side of the valve housing is the UNKNOWN air source im talking about
I tried to label them so i wouldnt forget.
This is the hose that i cant figure out where is comes from.
Last edited by RPMulli; 07-01-2010 at 01:11 AM.
06-30-2010, 10:34 PM
#107
After clearing all tubes, inspecting all lines and testing all valves. here are my conclusions on the vent system. there is one line that i cannot figure out where it goes and i think it is the culprit with my howling noise from behind the gas door..
06-30-2010, 10:36 PM
#109
Now, here are some notes that i wrote down as i was testing the system with the engine operating...
If i open the gas cap and push in the flapper (as if i were to refuel the car) the engine starts to bog down and die. ( i did this to figure out when the carbon valve operates)
The carbon valve is ALWAYS closed during operation of the engine
The shut-off valve is ALWAYS open until i pull the valve out of the housing while the engine is operating and then it tries to close.
If i open the gas cap and push in the flapper (as if i were to refuel the car) the engine starts to bog down and die. ( i did this to figure out when the carbon valve operates)
The carbon valve is ALWAYS closed during operation of the engine
The shut-off valve is ALWAYS open until i pull the valve out of the housing while the engine is operating and then it tries to close.
06-30-2010, 10:39 PM
#110
Conclusion, The howling noise from the vent behind the gas door leads to the carbon control valve. I think that the unknown air course that leads to the housing where the carbon valve and shutoff valve does not supply enough air through the tubing that leads back to the carbon canister. I believe that the engine is trying to suck enough air through the carbon canister and additional air ends up squeaking by the carbon control valve which ends up recirculating back to the intake manifold through the regeneration valve in the engine bay.
Last edited by RPMulli; 07-01-2010 at 08:10 AM.
06-30-2010, 10:41 PM
#111
Note:
When the engine was operating the regeneration valve was clicking on and off intermittently. Is this normal? As soon as i disconnected the harness from the valve the clicking stopped. I wonder why it would open and close like that.
When the engine was operating the regeneration valve was clicking on and off intermittently. Is this normal? As soon as i disconnected the harness from the valve the clicking stopped. I wonder why it would open and close like that.
Last edited by RPMulli; 07-01-2010 at 08:10 AM.
06-30-2010, 11:10 PM
#114
Another quick thought.... could someone remove the plug from their own regeneration valve while the engine is running and give me the voltage running to the valve? mine is ~ 10 volts. I want to make sure thats within spec.
Last edited by RPMulli; 07-01-2010 at 08:10 AM.
