Passing Kalif Smog with an Air/Fuel Mix Meter.

[Spike Strip]

Got tired of going into smog tests blind so I installed an Auto Meter A/F gauge to help "pre-tune" the rig before the test.

A little hard to install the O2 bung with the downpipe in the truck since there's little room to drill, unless you own a right-angle drill (I don't), so I installed it as far up as I could get it at about 4 o'clock so as not to let condensation hit the sensor, too much. Just a ground and tap into switched power, and you're good.

....

 

[2mbb]

so once the meter was installed, what did you do to "tune" the engine? Since it is a dyno test, adjusting the idle mixture doesn't seem like it's enough.

 

[Spike Strip]

Well, it really helps doing the "Lean-Drop" adjustment as it gives a concrete parameter, v. just using Vacuum and RPM. Also, cruising at speed, between 15 and 30 mph, you get an idea of what's going into the CAT: Only way I had of simulating a dyno (or does a dyno simulate the road ?). Anyway, it gave me confidence to see that truck was idling around 15:1 and at slow cruising a little under that. It also lets you know the decel cut and those things are working as when you let off the skinny, it quickly goes very lean. Stomp on the skinny and goes rich. ... Sensor should be placed above the Air Injection port in the downpipe.

I used an analog meter v. digital as I hate digi meters at night. Distracting.

For me, mainly, it's just a way of seeing that the smog crap seems to be working 'right'.

Anyway, not gonna worry about it again for two years!

 

[Dynosoar]

Cool beans

Dyno

 

[cruisermatt]

Was that running a 1/4 tank of the "magic solution" or just pump gas?

 

[The Machinist]

Damn that's practically cheating! Now that I think about it, I'm surprised I haven't seen more people doing this.

 

[Output Shaft]

Anyway, not gonna worry about it again for two years!

You just bought the gauge I've been eye balling!
That + a pyrometer to keep a tab on load.

I've read that O2 sensors have a limited life span and their output voltage deteriorates with age.
That being the case.... are you planning on keeping it installed "forever"? or just prior to the meeting with the gallows every two years?

It would be great if you could provide more data for the rest of us what the 2F A/F ratio is during:

1. 65-70 mph "fast cruising" on freeway (4th vs 5th gear)
   
2. 55 mph light throttle cruising on freeway (4th vs 5th gear)
   
3. Pushing the 2F up a mountain hill for a bit.. floored.

I think that info would be very interesting for all of us.

 

[sheepdawg]

You are right. Digital gauges are to distracting at night. I have the same gauge as Mark A.

My a/f gage does not register at 65 mph nor when floored, but at 55 mph light throttle, it's about 14. Perfect, otherwise it runs rich, but I am de smogged.

 

[Spike Strip]

Used pump gas only for the test -- However, tank was low last night, and I dumped in a bottle of 'HEET' before going to fill up, just to see if it made any difference on the gauge, and I'll be damned, 8 oz in around a 1/8 tank, changed the mix to a bit over 16:1 ! That stuff works!

If you have multiple carb'd vehicles, this is a better thing to get: LINK

As it's portable and all you have to do in weld in (or have welded) the bung that comes with a plug. You can also get a tail pipe adapter if you don't have a CAT. Not worried about longevity of O2 sensor - the Bosch goes 100000 miles.

Sheepdawg, it was seeing Mark A. install the gauge in shrek that made me know I needed one . Unfortunately, I don't have his skill for that cool in-dash installation !

 

[Output Shaft]

that cool in-dash installation

would like to see that too

 

[FishNinJay]

Was that running a 1/4 tank of the "magic solution" or just pump gas?

What is this? And would it help with an FJ62 or any fuel injected vehicle? Please elaborate. Much thanks..
-J

 

[cruisermatt]

What is this? And would it help with an FJ62 or any fuel injected vehicle? Please elaborate. Much thanks..
-J

I'm don't live in California and my state of Florida has no smog testing whatsoever, but what I've read is that most FJ62's pass smog with ease and little effort, however not entirely sure how accurate that is.

I know mine sure wouldn't.

As regards to the juice, either Spike Strip or NLXTACY posting a thread about a few months ago. I'm not sure how necessary it is with fuel injection or if it could even mess up injectors or something like that.

 

[FishNinJay]

Thanks.. I'll look those fellas up.. once I get my FJ62.

 

[Slow Left]

Got tired of going into smog tests blind so I installed an Auto Meter A/F gauge to help "pre-tune" the rig before the test.

A little hard to install the O2 bung with the downpipe in the truck since there's little room to drill, unless you own a right-angle drill (I don't), so I installed it as far up as I could get it at about 4 o'clock so as not to let condensation hit the sensor, too much. Just a ground and tap into switched power, and you're good.



View attachment 1030617 View attachment 1030618 View attachment 1030624

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Good stuff, Spike. Thanks for posting this up!

 

[DFXR]

Great idea. Going in blind on that first test of the cycle (of misery) always sucks. Congrats on passing clean, too.

Just to get my head around the numbers on the gauge and how they relate to your test results - you're getting roughly 15:1 at idle, a little less at the 15mph and 25mph speeds? Any idea what the low threshold would be for too rich?

 

[Spike Strip]

No idea what too rich for the test would be. I was just trying to get close to the theoretical 14.7:1 ideal mix, or leaner, and wanted to see how well this held up at cruising (test) speeds. Seemed to work well enough, but it's not a substitute for a malfunctioning system, just a diagnostic tool. But I'm told, even with a malfunctioning system, and the proper 'magic solution', A/F meter should tell you where you stand, just hoping your NOx isn't too high (too lean) ...

 

[DFXR]

I passed this summer with a large amount of tinkering, a small amount of magic...and a new cat. Numbers looked great. But now I've got a sulfur smell off the cat (well past the break in period), which tells me I'm rich and that I'm probably killing the thing.

I know the meter is not a substitute for running down the problem, but I do like the idea of having a gauge on what is definitely the most mysterious part of the whole LC package.

 

[Output Shaft]

just hoping your NOx isn't too high (too lean)

No need to hope..... just install an EGT pyrometer.
NOx comes from high combustion temps. The pyrometer would allow one to keep an eye on that as well.

Knowing A/F is a good tool for tuning and pre-smog verification, but lean or rich in itself does not correlate necessarily to engine stress.

Also knowing EGT along with head temp is a good tool to let one know what the significance of the A/F reading is.
An extremely lean mixture is harmless if the EGT is low.... but can be devastating if the EGT high.
I know... another gauge & sensor.

 

[Benjaman]

I'm not sure how necessary it is with fuel injection or if it could even mess up injectors or something like that.

It's necessary, and does not mess up injectors, it may even help clean them. It's worked well for me and others, on Fj62's.