High CO% Causing Smog Failure - Any Ideas? (1 Viewer)

[landscrambler]

Howdy all,

1988 FJ62 330k miles - failed smog twice. Both times were due to high CO (report below).

In the past few months, I have:
(In order of most recently performed)
- Throttle body cleaned
- checked coolant temp circuit at ECU
- replaced coolant temp sensor
- new AC compressor
- replaced throttle cable
- replaced o2 sensors
- checked for vacuum leaks
- replaced throttle position sensor
- replaced water pump

My truck has thrown lean / rich codes for the past 5 years (codes 25 and 26) and have still not been able to figure out how to fix that.

Other than all that, truck overall runs very well. Does smell strong of gas sometimes though.

Any help would be greatly appreciated, as I have the time these days to try and fix it myself.

And for those jokers, yes, I know I could move to a state that doesn't smog but that's not in the cards.

Thanks!~

 

[Spike Strip]

I'm not very familiar with the 3FE's, but your O2 is at Zero meaning your Air Injection is not working properly.... Others will say how/what to troubleshoot.

 

[landscrambler]

Interesting. Would that be a correlation or a causation to the CO being high?

 

[Spike Strip]

Yes (one of a few possible causes). High CO is caused by incomplete combustion. Part of the function of the AI system is a more complete burn.

Check you smog pump, air rail, check valves...

https://2fiftycc.com/cruiser/3FE%20Engine%20Repair%20Manual%20Suppliment.pdf

 

[SteveH]

See if your AIR pump is putting out much air, and/or add lots of E-85 and retest it. Yours is close to passing, so E85 will likely easily put it into the passing zone. There are threads all over the web on this - run the tank low on gas, put in several gallons of E85, retest, then quickly add more gas and burn out that ethanol crap.

 

[landscrambler]

See if your AIR pump is putting out much air, and/or add lots of E-85 and retest it. Yours is close to passing, so E85 will likely easily put it into the passing zone. There are threads all over the web on this - run the tank low on gas, put in several gallons of E85, retest, then quickly add more gas and burn out that ethanol crap.

Thanks!

How do I test my air pump?

 

[SteveH]

IMO, there is no great way to test an air pump, but if you take off the output hose and put your hand in front of it, there should be a pretty good breeze coming out of it at idle- not just a little air wandering out. Rev the engine a bit and see how much more you get at higher RPMs. I had a tired air pump that was missing chunks of the vanes and a replacement pump put out about 2x the air. 'How much air should come out' is subjective - so I'm just giving you vague guidelines here. You are so close to passing, that I think the E85 trick will vault you over the edge. A buddy of mine got a straight-6 '81 Ford pickup to pass with NO air pump, using just E-85. In his area, visual didn't matter.

 

[red66toy]

There should be a test procedure in the FSM.

 

[php74]

Get it nice and hot. I drive on the freeway at 70 mph for 30 minutes with AC on, then in parking lot of testing facility rev engine to 2500 for a solid 2 minutes, then run it through. I’ve done this the past 3 years on the advice of Cert Toyota mechanic. I go from failing scores to easily passing after doing this.

Do the necessary stuff first of course, but I was failing with new plugs, set timing, no vac leaks, new air intake hose (those can easily be badly cracked in the corrugated crevices), etc etc.