smerkinseven

ok, guys i just got my car smogged today... it took an hour and a half. there was two things that stopped my from passing.... the hc level and the co% the hc was not suppose to have more than 100.. i had 1200 and the co% was 1.0.... i had 6. something. after an hour and a half we found out that a hose that connects from the intake manifold to the fuel pressure reg..... now here is the funny thing.... there was a plug on the intake side.. why was that??? is there a trick or something??? but after we installed a new hose, the car was running much much leaner ( was running really really rich). now i passed the smog test and the car is running much much smoother... damn i didn't notice it...but my car wasn't really running right before.. what was that hose for?????

spurvo

I'm looking at page F-197 of the manual, which shows when each of the emission controls are actuated. It shows that the pressure regulator control is off (which is listed as "Vacuum to pressure regulator") for all engine operation except for hot start idle. The fuel line pressure is 28-32 psi for low pressure/typical operation, and 36 to 38 psi on hot start to help with vapor lock. So perhaps someone removed the vacuum hose to your regulator to increase the pressure all the time to reduce detonation by running rich, OR they thought it was necessary for high HP operation. That's my guess...