90 vs 91+ evap emissions system - ZR-1 Net Registry Forums

zr1don · 06-25-2006

I am installing a 1991 plenum, air horn & throttle body on a 1990 engine. There appears to be a difference in the evap emmissions systems on the two models. The 1990 has the cannister purge solenoid next to the cannister & the 91 has it under the plenum & I can't locate the ported vacuum fitting under the throttle body. I think I can remove the 91's vac plumbing from under the plenum & hook up the 90's purge line to the plenum fitting. The question I have is the ported vac line. There appears to be a boss on the bottom of the air horn that coould have been for a ported vac source? Can I drill & thread a vac fitting to provide the ported vac?

06-25-2006	#1
zr1don Join Date: Jan 2006 Location: Temecula, CA Posts: 92	90 vs 91+ evap emissions system I am installing a 1991 plenum, air horn & throttle body on a 1990 engine. There appears to be a difference in the evap emmissions systems on the two models. The 1990 has the cannister purge solenoid next to the cannister & the 91 has it under the plenum & I can't locate the ported vacuum fitting under the throttle body. I think I can remove the 91's vac plumbing from under the plenum & hook up the 90's purge line to the plenum fitting. The question I have is the ported vac line. There appears to be a boss on the bottom of the air horn that coould have been for a ported vac source? Can I drill & thread a vac fitting to provide the ported vac?