smog passing help

[4runnerrocker]

i have a 88 4 runner with a v 6. it did not pass smog. hc level was at 134 -max allowed 121 @15mph/ 128 -max allowed 101@25 mph.,, co% was 2.48- max allowed .70@15 mph/ 1.95 -max allowed .90 @25. they also stated that they couldnt time it because the mark was moving , they said it might be a slipping harmonic balancer? i was going to get some of that gaurtee to pass fuel additive. does anyone have any idea to get it pass it runs fine. i just put a new muffler and cat on it.

[JWG]

I know that on a 22RE motor, the ESA system will adjust the timing on the fly, so it's normal for the timing mark to move around a bit. However, during smog tests, I believe they usually short the T-E1 connector, at which time I think the timing should stay right at 8deg BTDC. I'm not familiar with the V6 motors, but they may operate on the same kind of system.

If the timing is indeed jumping around abnormally, your distributor could have some slop in it.

As for your smog results, was your catylitic converter nice and hot before the test? They won't clean the exhaust gases very well until they've been heated up. My truck wouldn't pass my last smog test, and I ended up having to put a new cat on it. Oddly enough, my truck wouldn't pass at the 15mph test, but would pass at the 25mph test.

John G

[OEMonkey]

did you pass NOx? what was o2 %? these are important #'s to look at for smog diagnosis.
check your VIR. did they fail you for timing? look under functional test.

[4runnerrocker]

Originally Posted by OEMonkey

did you pass NOx? what was o2 %? these are important #'s to look at for smog diagnosis.
check your VIR. did they fail you for timing? look under functional test.

i passed NOx , the max was 1006 @15mph and i was 522\ the max was 866@25mph and i was 663. my o2% was 0.1@15 and 0.0@25 . i failed HC and co% and i failed the timing cause they said they couldnt read it cause it was slipping, they said my harmonic balancer was loose. my VIR stated that i passed visual ,failed functional --due to the timing , failed emissions- gross polluter.

[OEMonkey]

First thing you gotta do is verify that the harmonic balancer is indeed loose and wobbly, enough to cause timing to jump around. You'd be surprised how many smog techs don't jump(or don't know how to jump) the connectors on the DLC when checking base timing especially at test only stations. Check the timing yourself. Jump T(or TE1) and E1 on the diagnosis box, and ensure your @10deg. BTDC. Again, fix the functional failure first then worry about the tailpipe emission. Looking at the numbers, seem like a bad cat. Look into anything that would cause the mixture to be on the rich side. Usually when it's running that pig rich(high CO, zero O2), NOx should be way down. But maintenance neglect on any vehicle will produce these kinda numbers. Old worn plugs w/ gaps way past spec and clogged or non-operational EGR system contribute mostly to high NOx. A rich AFR or timing thats retarded contribute to high CO. HC by itself don't usually fail. Usually when both CO and NOx pass, HC will pass as well. Unless there's a clogged PCV valve, overdue oil change, etc.(again, maintenance neglect.) There's really a lot of possibilities. Sure you can throw a new cat in there and it'll clean em up but it's just masking some problems and wont make your vehicle run the way it should. I recommend taking it to a pro as it's fairly difficult to diagnose a vehicle over the internet. Sorry, hope I at least helped a little bit.