Background:
- I'm finally going through the process of getting my '86 FJ60 smogged in CA so I can get a street parking permit, the truck has previously been out of state, but was getting driving a couple times a week and running well (got 14-15mpg driving 750 miles across NV/CA this past weekend)
- Under the hood the truck is all stock, its originally a NM truck and passed emissions there over the years
- The only tinkering that's been done to the emissions components has been swapping in 2 new VCVs a couple months ago, carb was last tuned in SLC (~4,400 ft); Mudrak also helped fix a leak in the intake manifold ~2 years ago
Situation:
- I drive ~30mins on the freeway (~2500-3000 rpms for a solid 15-29mins) to the smog shop, get tested... pass with pretty good numbers on emissions, but fail the visual because there is a crack in the hot air pipe that helps feed warm air to the carb when its cold out
- The smog shop agrees to give me a free re-test so I go next door to Napa get a replacement hot air pipe, install that and go back to get retested
- The truck probably sits for ~45 mins while I'm finding a pipe that fits; I also have to disconnect the hose that goes into the bottom of the EGR modulator and pop it off to get access to underneath the air cleaner. I put everything back on and head back to get retested
- During the retest I now pass the visual but fail emissions
+ CO @15mpg/25mpg went from .08/.06 on first test to 1.35/1.28 on second test (fail; max allowed is .79 /1.00)
+ NO jumped from 604/620 to 1580/1501 (fail; max is 1062/1073)
+ HC also jumped from 22/12 to 97/56 (pass; max is 125/96)
+ C02 decreased from 16.2/15.9 to 14.5/14.6
Questions:
- Is this symptomatic of the EGR not kicking in during the second test? (High CO means its running rich? High NOx means EGR isn't working?)
- Could I have knocked some soot in the EGR modulator loose when I moved it around while installing the hot air pipe (which shouldn't impact emissions)?
- Would the ~45mins of cooling off have made this much of a difference in the test?
I'm honestly a bit stumped as to why the results from 2 tests within ~1hr could vary so much, but I'm tempted to replace the EGR modulator and get it nice and hot before trying to test again this weekend (will be ~$30 for another retest). I am also planning to get a t-case rebuild done at Valley Hybrids in two weeks, so can probably get some help from @orangefj45 if all else fails
- I'm finally going through the process of getting my '86 FJ60 smogged in CA so I can get a street parking permit, the truck has previously been out of state, but was getting driving a couple times a week and running well (got 14-15mpg driving 750 miles across NV/CA this past weekend)
- Under the hood the truck is all stock, its originally a NM truck and passed emissions there over the years
- The only tinkering that's been done to the emissions components has been swapping in 2 new VCVs a couple months ago, carb was last tuned in SLC (~4,400 ft); Mudrak also helped fix a leak in the intake manifold ~2 years ago
Situation:
- I drive ~30mins on the freeway (~2500-3000 rpms for a solid 15-29mins) to the smog shop, get tested... pass with pretty good numbers on emissions, but fail the visual because there is a crack in the hot air pipe that helps feed warm air to the carb when its cold out
- The smog shop agrees to give me a free re-test so I go next door to Napa get a replacement hot air pipe, install that and go back to get retested
- The truck probably sits for ~45 mins while I'm finding a pipe that fits; I also have to disconnect the hose that goes into the bottom of the EGR modulator and pop it off to get access to underneath the air cleaner. I put everything back on and head back to get retested
- During the retest I now pass the visual but fail emissions
+ CO @15mpg/25mpg went from .08/.06 on first test to 1.35/1.28 on second test (fail; max allowed is .79 /1.00)
+ NO jumped from 604/620 to 1580/1501 (fail; max is 1062/1073)
+ HC also jumped from 22/12 to 97/56 (pass; max is 125/96)
+ C02 decreased from 16.2/15.9 to 14.5/14.6
Questions:
- Is this symptomatic of the EGR not kicking in during the second test? (High CO means its running rich? High NOx means EGR isn't working?)
- Could I have knocked some soot in the EGR modulator loose when I moved it around while installing the hot air pipe (which shouldn't impact emissions)?
- Would the ~45mins of cooling off have made this much of a difference in the test?
I'm honestly a bit stumped as to why the results from 2 tests within ~1hr could vary so much, but I'm tempted to replace the EGR modulator and get it nice and hot before trying to test again this weekend (will be ~$30 for another retest). I am also planning to get a t-case rebuild done at Valley Hybrids in two weeks, so can probably get some help from @orangefj45 if all else fails