Passed smog...yippeeeee

[Eric Kropp]

I posted a while back that my 1983 2.8 with 350,000 miles had high hydro-carbons and carbon monoxide at idle. I found that the air control valve from the smog pump was shot. Found one at pick and pull and put it on. From the reading I did in the manual, the control valve opens around 1500 rpm and allows air into the cat and exhaust manifolds to raise the temp and burn off hydro's and c.o.'s, kind of like when oxygen is punched into a cutting torch...I think. So my thought was to introduce air at idle and maybe have the same effect, and sure enough it did. So I did some very careful mods to the vacuum line hook up (has to look factory original for the visual inspection) at the solenoid that allows vacuum to the control valve and BAM she passes. I believe the reason it originally didn't pass is because there is just to much blow by. I now have a year and a half or so to rebuild a donor engine and fix the problem the right way. I can't wait to see how it runs with a fresh engine.

Eric<><

 

[BeaterMan]

Wow getting some miles on her huh? Sometimes vehicles fail because of the idiot driving it on the dyno. One time my truck failed and I was watching the screen- tech wasnt paying attention or keeping correct speed. I drove it out of the bay and went right around to retest in another bay and bam it passed.

 

[Eric Kropp]

Just for the record....I also did the things that this forum said to do regarding smog tests, like change the oil, clean the fill cap/vent that leads into the air filter and put premium fuel in the darn near empty tank to get me the hottest fire. I also have a buddy that has a Sun diagnostic center and we hooked the little dude up and checked all the vitals. It is amazing the difference it can make in the hydrocarbon/c.o. reads just by adjusting the idle speed. We had it pretty well dialed before I took it to the smog shop, but I still felt a little "Russian roulette-ish" when I left it there.....

Eric