89VORTEC
09-22-07, 12:00 AM
Well its that time of year again ... and guess what, my 89 tbi pickup failed again this year, but not as bad. Background info, 4.3 TBI, Pennsylvania emissions, 240K Miles, had the truck since 10/06, runs great since i resurrected it from '04, lol.
Failed for Hydrocarbons this time, instead of all across the board (had to get a waiver last year, lol).
HC was 715 ppm .... the PA limit is 570 ppm. Passed on CO%, 1.15% on 5.5%, passed on NOx, 1342 on 5243. (numbers are estimated, but close, since i left my test results printout at work)
HC only failed by about 150 ppm. This is a very small amount. What can i do to get this down a bit??
Full tune-up since last year, belden wires, acdelco regular plugs, rebuilt TBI with lower mileage injectors, new cat, all that stuff. I DO HAVE MY TIMING ADVANCED BY LIKE 2*-4* .... could this be causing the excess unburned fuel? ... I could also swap my msd blaster coil from my 94 blazer ... might this help too? ... remember all i need is a small amount of HC reduction to pass. Is there anything i can put in the tank to help create a more complete burn?
Thanks in advance for any suggestions
Dan
Failed for Hydrocarbons this time, instead of all across the board (had to get a waiver last year, lol).
HC was 715 ppm .... the PA limit is 570 ppm. Passed on CO%, 1.15% on 5.5%, passed on NOx, 1342 on 5243. (numbers are estimated, but close, since i left my test results printout at work)
HC only failed by about 150 ppm. This is a very small amount. What can i do to get this down a bit??
Full tune-up since last year, belden wires, acdelco regular plugs, rebuilt TBI with lower mileage injectors, new cat, all that stuff. I DO HAVE MY TIMING ADVANCED BY LIKE 2*-4* .... could this be causing the excess unburned fuel? ... I could also swap my msd blaster coil from my 94 blazer ... might this help too? ... remember all i need is a small amount of HC reduction to pass. Is there anything i can put in the tank to help create a more complete burn?
Thanks in advance for any suggestions
Dan