Failed Emissions high CO with ABV vented (02 into exhaust stream), passed 5K miles ago

[Infinity00]

1985 FJ60 with 217,234 miles. Rebuilt engine & carb, all emissions was working when it passed 5,000 miles and 6 years ago.
New 5 speed, 33" tires. Passing test results in 2018 @ 212,189 miles: HC 1.1057, CO 9.5632, Nox 1.6973 CO2 752.7458

1st failed test results 217,180 miles:
HC: 1.7525 limit 4.0000 PASS
CO: 75.4628 limit 45.0000 FAIL
Nox: 1.0542 limit 5.0000 PASS
CO2: 692.3288

2nd failed test results 217,234 miles
HC: 1.3628
CO: 52.0268 limit 45.0000 FAIL
Nox: 1.3015
CO2: 678.2393

The test results are getting closer to passing. I don't want to get a carb compliant cat as they start around $1,000 and I just put one on 5,000 miles ago, so I want to try other things. I really want to do one thing at a time, but I only have one free test. Both tests done after highway speeds and engine fully warmed up. No accessories on.

• Question, is it better to have good oxygen from the smog pump go to the exhaust-j pipe, or to the air rail (it can't be setup to go to both, only one or the other). I have good air flow especially at higher rpms. I have the oxygen going into the exhaust j-pipe thinking that would be best, but I could plug the ABV port causing the air to go into the air rail instead. Is this better?
• Question, does retarding the dizzy, or even removing the vacuum that the HAC is supplying helpful? Last time I tested when it passed, my HAC diaphragm was bad so the dizzy was what it was without the high altitude adjustment. I may have had it slightly advanced by rotation of the dizzy but not nearly as much as it is now. It may have been closer to 7 or 9 deg BTDC but I really don't remember

1st Failed Test:
Miles: 217,180 - engine rebuilt at around 200,000 miles, carb rebuilt and leaned out before testing, using lean drop method. Leaned 1/4 turn more after 1st failure
Dizzy set to static 7 degrees BTDC, HAC working, pulls to ~14 degrees BTDC, vacuum advance working, no changes made after 1st failure

Changes after 1st failed test:

• leaned out another 1/4 turn clockwise, using lean drop method plus 1/4 turn. Have AFR meter reading 15.1-15.3 when idling and cruising highway speeds it might drop to 14.7, and cruising at 45 mph AFR reading 13.1-13.5
• Air Injection VTV port F broke off while I was testing for air going into the air rail, so I left ABV vented; meaning AI sending oxygen directly to exhaust j-pipe, check valves new when engine rebuilt
• Added 6 gallons of 91 octane to near empty tank

Things I didn't do YET, as it passed 5,000 miles ago with flying colors, see bottom test

1. smaller main jet
2. change air filter
3. change oil
4. change spark plugs
5. retard dizzy
6. put smaller tires on it and inflate to 40 psi
7. no E-85 added, no heat added
8. cat 5,000 miles old, didn't replace
9. adjust valves
10. check pcv

 

[2mbb]

That's a fancy report compared to California, but too bad there is no residual oxygen measurements from the tail pipe. It also looks like it is a dyno test. I'm not sure how important the idle mixture screw setting is (leaning out 1/4 turn for example), when the test is not done at idle. The other carburetor systems must be contributing more to the fuel mixture than the idle setting.

If you have the ACV set to always route AI into the exhaust pipe, then you should also check the other components--air pump output, the check valve, the AI relief valve,, etc. A local smog tech that is working on another customers FJ60 discovered a check valve that was clogged/frozen; My relief valve seemed to be leaking air.

I recently went through an ordeal with California smog. I had both high HC and CO. You can read more here. I tried two different carburetors, sourced used AI valves, rebuilt my air pump, ran through all the tests in the emissions manual. Eventually I installed a new catalytic converter to get it to pass. I'm not saying you need a new cat, but you need to check all the components to be successful. Good Luck.

 

[Spike Strip]

High CO is from 'Incomplete Combustion' - Your pics don't show O2 levels so no idea if Air Injection is working, although your AF meter readings seem good, if not a little lean (mine reads pretty close to yours FWIW).

When you say 'VTV' nipple broke, the VTV is the Blue/White round valve - Is that what you're talking about?

In any case, if you have the Air Pump always directed to the downpipe that means there's less Oxy for the combustion. Your O2 levels at the pipe will increase but combustion will be less complete.

I'd fix/replace the broken bits and retest. Maybe lean the mix out another 1/8 turn or so, and see what the A/F meter says. That's how I do mine. If it goes too lean, back off the same amount.

And, if you put a 1.38 primary jet in, it will always pass.

 

[Infinity00]

That's a fancy report compared to California, but too bad there is no residual oxygen measurements from the tail pipe. It also looks like it is a dyno test. I'm not sure how important the idle mixture screw setting is (leaning out 1/4 turn for example), when the test is not done at idle. The other carburetor systems must be contributing more to the fuel mixture than the idle setting.

If you have the ACV set to always route AI into the exhaust pipe, then you should also check the other components--air pump output, the check valve, the AI relief valve,, etc. A local smog tech that is working on another customers FJ60 discovered a check valve that was clogged/frozen; My relief valve seemed to be leaking air.

I recently went through an ordeal with California smog. I had both high HC and CO. You can read more here. I tried two different carburetors, sourced used AI valves, rebuilt my air pump, ran through all the tests in the emissions manual. Eventually I installed a new catalytic converter to get it to pass. I'm not saying you need a new cat, but you need to check all the components to be successful. Good Luck.

dyno test, it was on rollers
air pump output seemed good especially at higher rpms (probably why the numbers got better at higher speeds). I might need to adjust my idle to 950 rpms, they don't care what it's at
check valves newish, maybe 12,000 miles old. I do need to check relief valve. One I had laying around but didn't use was def leaking
cat is only 5,000 miles old. Hate to replace again but know this might be the way
I've read all your failed emissions probably where I got my summation of what to check next!

 

[Infinity00]

High CO is from 'Incomplete Combustion' - Your pics don't show O2 levels so no idea if Air Injection is working, although your AF meter readings seem good, if not a little lean (mine reads pretty close to yours FWIW).

When you say 'VTV' nipple broke, the VTV is the Blue/White round valve - Is that what you're talking about?

In any case, if you have the Air Pump always directed to the downpipe that means there's less Oxy for the combustion. Your O2 levels at the pipe will increase but combustion will be less complete.

I'd fix/replace the broken bits and retest. Maybe lean the mix out another 1/8 turn or so, and see what the A/F meter says. That's how I do mine. If it goes too lean, back off the same amount.

And, if you put a 1.38 primary jet in, it will always pass.

Sorry I meant vsv2, the solenoid that operates whether the vacuum goes to the abv top port or not (I don't have my fsm in front of me so I could have it wrong still, but yeah its the solenoid valve, not the vtv), my vtvs are new 5,000 miles ago.
So, when you say there's less o2 for the combustion, in my other configuration air goes to the air rail when I have the abv top port has vacuum (vsv1 may control whether it has vacuum under certain conditions but lets just say mine has vacuum all the time forcing the air rail to get o2). Doesn't that just add air into my exhaust side of the valves? How does that help combustion? Interestingly, I did drive it over to the smog station with it configured that way and it did seem like the AFR wasn't reading as low at 45 mph. I'd love to learn more about how it helps the combustion. The first test was with all the bits fixed, and it failed, so I took advantage of the situation...
Is the 1.38 primary still available? I have no problem doing that

What do you think about retarding the dizzy or just plugging the HAC advance on the vacuum can. I was reading alot about that last night but nothing definitive came out of my reading.

If I didn't just get 18" of snow I'd head down to work on it today. Chose poorly to test when I did even though I've been waiting for the best 10 day stretch I forgot to check for snow!!!

 

[Infinity00]

Ordered a couple jets from Jet R Us. The thread pitch might not be quite right but I’ll deal with that when they get here

 

[Spike Strip]

Mikuni Jets work, IIRC. Otherwise the FJ60 Non-USA NAPCO kits have a 1.38 primary jet. Some on ebay.

I retard the dissy to 5* for the test to lower NOx. In Calif, you can only be +/- 2* from stock or you'll fail. Don't know about CO.

HAC will lean out the mix about 5% or so, above 4k feet elevation. Good to have it working if you're above that (assuming HAC valve is working).

 

[2mbb]

I installed the Mikuni jets in my carburetor . I measured my old jets to have an M5x0.8 thread pitch. The Mikuni's were specified as M5x0.7, but when I got them, the thread pitch looked the same as the originals. I got stock sizes (147.5 and 200) and had them in for my first round of smog tests, but as I failed smog so many times, I eventually put the OEM jets back in. However, now that I have passed CA smog, I put the Mikuni's back in...

The OEM jets have a straight bore that measures between 1.45 and 1.50mm and 2.00mm for primary and secondary respectively. (I have a set of wire gauges that I used to measure the bore size). The Mikuni jets have an hourglass shaped bore and the smallest diameter for the 200 jet measures larger than 2.00. I'm not sure if I tried measuring the 147.5 Mikuni jet.

 

[Infinity00]

Funny, I just dug through a bunch of old posts and saw your reference to Napco. I emailed the eBay vendor to see if the jets are still included bc when I’ve bought the keyster kits, even back in 2017 or ‘18 the jets were never included. You also mentioned in those posts that the accelerator pump cover doesn’t disintegrate on the Napco, that’s my keyster nemesis, torn pump cover after a couple years. Plus the “leather” on the accelerator pump is a bonus. I think Keyster does have this …
Edit: keyster doesn’t have the leather one.

my HAC is working, but I should check the pipe going to the carb again to make sure they aren’t plugged. I’m at 6300’ and the HAC adds the 6 degrees advance. Colorado doesn’t check timing so I might plug that additional advance for now. When I passed the last time, my vacuum advance outer wasn’t working, and that’s why I’m wondering if less advance might be better for passing emissions on my truck. @NeverGiveUpYota was nice enough to send me one of her good ones so I have a working one now.

 

[Infinity00]

I installed the Mikuni jets in my carburetor . I measured my old jets to have an M5x0.8 thread pitch. The Mikuni's were specified as M5x0.7, but when I got them, the thread pitch looked the same as the originals. I got stock sizes (147.5 and 200) and had them in for my first round of smog tests, but as I failed smog so many times, I eventually put the OEM jets back in. However, now that I have passed CA smog, I put the Mikuni's back in...

The OEM jets have a straight bore that measures between 1.45 and 1.50mm and 2.00mm for primary and secondary respectively. (I have a set of wire gauges that I used to measure the bore size). The Mikuni jets have an hourglass shaped bore and the smallest diameter for the 200 jet measures larger than 2.00. I'm not sure if I tried measuring the 147.5 Mikuni jet.

I bought the 137.5 and 140. Good to hear the pitch is that close. I’ll let you all know how it goes tomorrow when I retest. Jets won’t be here for awhile so I’m going to try a few of the other things and see what numbers I can get

 

[CruiserTrash]

@Infinity00

I responded over on the Rising Sun forum, but you’ve got a lot more info here. These trucks pass roller emissions testing when they’re tuned up and all the emissions system gadgets are 100% working. They just do. I think throwing jets at it covers up the real problem and you’ll end up chasing your tail - if not now, then on the next test. If you get everything working now that makes the next one easier.

I‘ve had a cabin mounted AF gauge for years and these trucks like to run lean. I think Toyota was shooting for lowest CO possible in order to hit EPA targets. This was before NOx testing was a concern so they didn’t have to have a balanced air fuel ratio, and the stock cooling system could handle the heat - so **** it, design them to run super lean and ship them to dealers. That’s my theory anyway. So I’m stock form these things typically easily pass the CO test but have trouble with NOx.

I’m going to respectfully disagree with @Spike Strip (a rare occurrence) on the actual AF numbers. Idle doesn’t really matter with the roller test … I run 15 at 50% throttle, 15.5-17 at 80% throttle (regular highway cruise), and 13.5-14 at WOT when the secondary opens. It’s been the same on two 60s I’ve own and a third one that did not belong to me. Like I said, I’m convinced Toyota designed these to run lean, so if you get those numbers that means most emissions systems are working. If you’re seeing wildly different numbers, something isn’t quite right.

In addition to advancing static timing 4*, the HAC also puts air into the intake manifold at the base of the carb to lean out the mix at altitude (where the air has less oxygen). Down here in Denver the HAC contributes to sometimes running at 17+ on the AF while cruising on the highway. I actually put a 25cc (red) VCV on the main air feed from the HAC to choke that off a bit and it runs at 15.5-16.5 now. Runs better, runs cooler, less NOx on the smog test. My own little “hack” but not necessary.

I’ll post the graph here again:

So either you are running too rich, or your air injection system ****ery is fooling your O2 sensor, or both. Your numbers are much richer than I’ve seen in other 60s, and rich corresponds to too much CO. If that ain’t a smoking gun…

I would:
Change the oil
Change the spark plugs
Change the air filter (more air!)
Set the timing to 7* (HAC unplugged)
Make sure the HAC is working

That might be enough. If not:
Make SURE the ACV and ABV and all the air injection stuff is routing the smog pump air correctly. Let it do it’s job, don’t try to force it.

 

[Infinity00]

Interesting and informative post. Thank you for clearly writing it up. That graph alone is worth all the trouble we’ve (many of us here) have had!

I’ll give those things a try tomorrow and get back to everyone

 

[CruiserTrash]

Interesting and informative post. Thank you for clearly writing it up. That graph alone is worth all the trouble we’ve (many of us here) have had!

I’ll give those things a try tomorrow and get back to everyone

Yes, let us know!

 

[Spike Strip]

@Infinity00

I responded over on the Rising Sun forum, but you’ve got a lot more info here. These trucks pass roller emissions testing when they’re tuned up and all the emissions system gadgets are 100% working. They just do. I think throwing jets at it covers up the real problem and you’ll end up chasing your tail - if not now, then on the next test. If you get everything working now that makes the next one easier.

I‘ve had a cabin mounted AF gauge for years and these trucks like to run lean. I think Toyota was shooting for lowest CO possible in order to hit EPA targets. This was before NOx testing was a concern so they didn’t have to have a balanced air fuel ratio, and the stock cooling system could handle the heat - so **** it, design them to run super lean and ship them to dealers. That’s my theory anyway. So I’m stock form these things typically easily pass the CO test but have trouble with NOx.

I’m going to respectfully disagree with @Spike Strip (a rare occurrence) on the actual AF numbers. Idle doesn’t really matter with the roller test … I run 15 at 50% throttle, 15.5-17 at 80% throttle (regular highway cruise), and 13.5-14 at WOT when the secondary opens. It’s been the same on two 60s I’ve own and a third one that did not belong to me. Like I said, I’m convinced Toyota designed these to run lean, so if you get those numbers that means most emissions systems are working. If you’re seeing wildly different numbers, something isn’t quite right.

In addition to advancing static timing 4*, the HAC also puts air into the intake manifold at the base of the carb to lean out the mix at altitude (where the air has less oxygen). Down here in Denver the HAC contributes to sometimes running at 17+ on the AF while cruising on the highway. I actually put a 25cc (red) VCV on the main air feed from the HAC to choke that off a bit and it runs at 15.5-16.5 now. Runs better, runs cooler, less NOx on the smog test. My own little “hack” but not necessary.

I’ll post the graph here again:


So either you are running too rich, or your air injection system ****ery is fooling your O2 sensor, or both. Your numbers are much richer than I’ve seen in other 60s, and rich corresponds to too much CO. If that ain’t a smoking gun…

I would:
Change the oil
Change the spark plugs
Change the air filter (more air!)
Set the timing to 7* (HAC unplugged)
Make sure the HAC is working

That might be enough. If not:
Make SURE the ACV and ABV and all the air injection stuff is routing the smog pump air correctly. Let it do it’s job, don’t try to force it.

Jim C commented a long time ago that the FJ60 was set up to run 'Fat' for that giant OE CAT. That would be supported by the fact the stock primary jet is 1.47, largest stock jet in any carb'd land cruiser. But the stock CAT probably had three times the catalyst and three times the catalytic surface area as a modern high-flow aftermarket, so whatever reasoning was behind Toyota's choices is probably gone when the CAT is replaced with a modern one.

So maybe with the newer CAT lean(er) is better? I'm at about 800ft sea level so I don't worry about HAC.

I don't run much advance beyond stock, maybe 9* 'cuz I want to run regular gas (87) and the gas here in L.A. is blended crap anyway.

Based on CruiserTrash's data, I'm going to try and lean the mix out a bit and see how she runs.

Unfortunately, I run an Analog A/F meter (I wanted to match some of the stock gauges), but it's a little difficult to get precise readings. I will swap out eventually for Digital gauge which is much easier to read.

And FWIW, anyone who has is running an Autometer A/F gauge, the replacement O2 sensor from Autometer is around $125+, but it's just a Bosch 17018 which is less than half the price:

https://www.amazon.com/Bosch-17018-Oxygen-Sensor-Fitment/dp/B000BZL0LC

 

[Infinity00]

Good to know, I have the auto meter. Its o2 is located on the down pipe circled in yellow

And I just pulled my plugs. Running rich for sure. I did have problems starting it this morning and flooded it. I had to pop my air cleaner cover off to get it started. Air filter on the way to the parts store. I don’t think flooding it caused it to be that fouled though but may have contributed to some wetness.

 

[CruiserTrash]

Good to know, I have the auto meter. Its o2 is located on the down pipe circled in yellow

And I just pulled my plugs. Running rich for sure. I did have problems starting it this morning and flooded it. I had to pop my air cleaner cover off to get it started. Air filter in the way. I don’t think flooding it caused it to be that fouled though but may have contributed to some wetness.

View attachment 3768223

View attachment 3768224

I have an Autometer AF gauge as well, and my sensor is plumbed about 9" further back than yours. Not as ideal as further upstream, but it hasn't given me any issues.

 

[Infinity00]

Replaced the fouled plugs, gapped to 0.031” & torqued to 13 Ft lbs

Emissions that have checked good so far:
- HAC tests good. Pipes going to the carb ports are correct and clean
- PCV was easy to blow into from the bottom to the top passing that test. Blowing from the other direction is supposed to allow a small amount of air to pass. It didn’t, until I sprayed it out and put some compressed air thru it, then it allowed a small amount of air to pass. It may have passed without cleaning if I used the compressed air first. Will probably order a new one for the future.
-evap controll valve is working, evap VTV plumbed and working correctly. Was new 5K miles ago
-evap cannister not plugged air blown into tank and purge port flowed out the other ports. I haven’t had a chance to test it while it’s running and warmed up yet.
-choke pulloff plate at 90 degs (wide open) when cold and not running - need to watch it while it’s warming up
-Dizzy innards still looked good, rotor looks new, both vacuum advances working. Springs are a little weird feeling when I twist the rotor but its working based on increased rpm advance the timing

Potential issues:
-Plugs were fouled, replaced with NGK standard copper BPR5ES. Old ones removed were BPR5EY
-found a small amount of liquid, probably gas on the hose going to the evap cannister tank valve when I removed the hose.
-springs in dizzy feel a little crunchy. Double check the centrifugal advance is working correctly. I have another dizzy that I “recurved” for desmog. The springs are new so I could put that in at last resort

Edit:
**** maybe found something here*****
***********************************************
my idle mix was set to 2 7/8 turns out. Seems too rich given my altitude and the fact that I performed the lean drop and then closed it off another 1/4 turn. So maybe there’s something not quite right with my carb setup.
************************************************

It was too cold and snowy to replace the oil yet but I’ll do that and put the air filter on and check a few more emission things before I retest for CO

 

[CruiserTrash]

Replaced the fouled plugs, gapped to 0.031” & torqued to 13 Ft lbs

Emissions that have checked good so far:
- HAC tests good. Pipes going to the carb ports are correct and clean
- PCV was easy to blow into from the bottom to the top passing that test. Blowing from the other direction is supposed to allow a small amount of air to pass. It didn’t, until I sprayed it out and put some compressed air thru it, then it allowed a small amount of air to pass. It may have passed without cleaning if I used the compressed air first. Will probably order a new one for the future.
-evap controll valve is working, evap VTV plumbed and working correctly. Was new 5K miles ago
-evap cannister not plugged air blown into tank and purge port flowed out the other ports. I haven’t had a chance to test it while it’s running and warmed up yet.
-choke pulloff plate at 90 degs (wide open) when cold and not running - need to watch it while it’s warming up
-Dizzy innards still looked good, rotor looks new, both vacuum advances working. Springs are a little weird feeling when I twist the rotor but its working based on increased rpm advance the timing

Potential issues:
-Plugs were fouled, replaced with NGK standard copper BPR5ES. Old ones removed were BPR5EY
-found a small amount of liquid, probably gas on the hose going to the evap cannister tank valve when I removed the hose.
-springs in dizzy feel a little crunchy. Double check the centrifugal advance is working correctly. I have another dizzy that I “recurved” for desmog. The springs are new so I could put that in at last resort

Edit:
**** maybe found something here*****
***********************************************
my idle mix was set to 2 7/8 turns out. Seems too rich given my altitude and the fact that I performed the lean drop and then closed it off another 1/4 turn. So maybe there’s something not quite right with my carb setup.
************************************************

It was too cold and snowy to replace the oil yet but I’ll do that and put the air filter on and check a few more emission things before I retest for CO

Crunchy dizzy might be the stop pin bushings. They were plastic and got around metal posts to limit the total advance (I think specifically the mechanical advance only, but that might be wrong). The plastic gets brittle, falls apart, and rattles around in there. That’s something that can be fixed with hardware store stuff drilled out to size: plastic or aluminum tube cut to length, premade bushings with the inner diameter widened if needed, etc. it might not affect anything to have the plastic bits in there, but it might be limiting advance if it’s binding the weights or springs. If the advance was getting jammed up, the fuel might not get a complete burn and your hydrocarbons would be high … I think. Sounds like this is not the issue.

May as well add another lean drop to your list. It only takes 10 minutes. Valve lash too if you have a spare hour.

Hope you don’t get too buried in the mountains! Everything’s melting as it hits the ground here in Denver.

 

[Infinity00]

I hate doing valves!!!!! The worst job ever in my opinion. The whole “while it’s running” I hate, but I’ve found doing it cold and not running really doesn’t get it close enough. Even after adjusting for the cold gap difference. Warm and not running doesn’t quite get it there either

 

[CruiserTrash]

I hate doing valves!!!!! The worst job ever in my opinion. The whole “while it’s running” I hate, but I’ve found doing it cold and not running really doesn’t get it close enough. Even after adjusting for the cold gap difference. Warm and not running doesn’t quite get it there either

I’ve always had good luck doing it on a hot engine that gets shut off. I’ve got it down to where I can peel the air cleaner, hoses, and valve cover off in about 12-15 minutes. And the adjustments go pretty quick, maybe another 15 minutes. Leaning over the engine bay requires some rags on hot parts so you don’t burn yourself and a LOT of core and upper body strength (which I don’t have haha), but it can be done. I’ve never done it while the motor is running - that scares me!