Emissions Help Needed (2 Viewers)

[DieselFJ]

Hopefully a quick question, my 84 FJ60 has high CO‘s at high idle test. I’ve rebuilt the carb, adjusted the valves and timing repaired the AI system, new plugs, wire, cap and rotor, verified no intake leaks. Adjusted the carb while on the sniffer. I was able to get HC’s and CO’s in spec at idle, and HC’s at high idle, but I can’t control the CO’s. Thoughts on what could be causing the issue?

Thanks in advance
Scott

 

[OSS]

Old worn out catalytic converter?
Dirty air cleaner?
Plugged PCV system?

High CO is caused by incomplete combustion- engine is running too rich

 

[DieselFJ]

Old worn out catalytic converter?
Dirty air cleaner?
Plugged PCV system?

High CO is caused by incomplete combustion- engine is running too rich

It’s an original catalytic converter from what I can tell it’s never been replaced. PCV and Air cleaner are new, I’ll have to check the lines to verify there is not a clog in the PCV circuit.

Thanks!

 

[OSS]

A 39 year old original catalytic converter is highly suspect. @Spike Strip knows which replacement to get if it comes to that.

 

[OSS]

Here’s the CA smog results from my last two tests for reference (‘86 FJ60). Passed.
Engine used to pass with flying colors when it was a few decades younger- ha.
The %O2 needs to be up near my values. It shows that the ai system is working. If %O2 is low, CO will be higher.

 

[ToyotaMatt]

Here’s the CA smog results from my last two tests for reference (‘86 FJ60). Passed.
Engine used to pass with flying colors when it was a few decades younger- ha.
The %O2 needs to be up near my values. It shows that the ai system is working. If %O2 is low, CO will be higher.

View attachment 3450197

 

[DieselFJ]

Here’s the CA smog results from my last two tests for reference (‘86 FJ60). Passed.
Engine used to pass with flying colors when it was a few decades younger- ha.
The %O2 needs to be up near my values. It shows that the ai system is working. If %O2 is low, CO will be higher.

View attachment 3450197

I don’t get that much information in my report, I wish they’d provided more data to help troubleshoot, but because of your help I did find a major issue that should help, the PCV circuit was clogged at the intake which would explain other issues ie. excessive oil consumption and possibly a hesitation/lag issue. Anyway, I’ll be addressing this today hopefully and will see what the outcome is.

Thanks!

 

[Spike Strip]

High CO is because of incomplete combustion.

So, running rich above 25 mph. Air Injection not working or not pumping in enough O2 at speed. Emissions computer malfunction.

Also, if you have the original CAT, probably time for a new one.

Essentially, it's too much fuel, or not enough Air, or bat CAT.

 

[DieselFJ]

Thanks for the input, I cleaned the PCV circuit out which was completely clogged with carbon. I reset the carb and timing. I’ll go tomorrow to see what the outcome of the work does for numbers. I did check the AI system and everything checks out minus the temp probe in the cat, I wasn’t getting the required reading so I’m guessing that’s bad, but it’s NLA so not sure of options for a replacement. I’ve checked everything per the emissions FSM for the emissions computer, not sure there is anything more I can check. BTW, the drivability issue cleared up with clearing the PCV issue so that’s great news. I see Magnaflow makes a direct fit replacement for this cat, anyone have any better options?

 

[Spike Strip]

Magnaflow is the best, and still affordable in the 48 State version. Rock Auto used to have the best price

 

[DieselFJ]

Well, after cleaning up the PCV my CO's at high speed test are where they need to be, but the HC's are over, and at idle both the HC's and CO's are over. At idle the HC's are reading roughly 550PPM, and the CO's are 2.2, and at High speed the HC's are around 700, and the CO's are 1.0. These are rough numbers, but just providing a generic idea. How much will a new catalytic convertor clean up the exhaust?

Thanks
Scott

 

[OSS]

I know you said you went through the air injection system- but it’s tricky to verify if it’s working properly.
One hack that has gotten edge cases through the test is flipping a vacuum hose on the ABV so that the air continuously pumps via the bypass directly into the exhaust pipe- as if you were at high speed.
The extra air entering the cat seems to help either through a chemical conversion (typical cat) or simply by dilution.

I don’t remember which vacuum hose gets flipped but you can figure it out by studying the emissions fsm.

If you’re not up for flipping vacuum hoses on the ABV, at least check the function of the check valve leading into the air injection manifold. If it’s stuck, air won’t flow into the exhaust ports.

 

[DieselFJ]

I will check the AI system again, to see if I missed something, but I did verify the check valves at both the exhaust and the air rail locations. What I didn't check was each port at the Injection Manifold and the actual pressure from the air pump. I don't mind flipping the vacuum hose, I might have to give that a try next time it's down.

 

[salvage60]

For what its worth I have been chasing this for years. I just failed yesterday for high CO @ 25mph and the O2 was 0. I have a pretty fresh rebuild, good compression, and more or less everything in working order. Looking back I think my AI quit working a few smog cycles ago but the good motor and new cat hid it, time to go though the checks again...

 

[DieselFJ]

The reason I haven't purchased a CAT yet was I'm thinking there is another underlying issue which I believe now is the AI system. I'm going to dig into this further this weekend to see if I can find the problem. If I can't figure this out Utah has passed a law that an '84 can no longer be registered in any way without either becoming compliant or purchasing expensive insurance and running vintage tags. This is a real problem since pretty much all emissions equipment has been discontinued.

 

[Spike Strip]

Utahfornia

 

[Rgill]

Have you verified base timing and total timing advance?

 

[Spike Strip]

You need 6-7 psi out of the air pump for the AI system to work properly.

You can see from the AI system schematic (fig 1) it's possible to manipulate the vacuum hoses at the ABV and ASV so the air pump output is constantly directed to the downpipe exhaust (@OSS alludes to this above). The solid-black sections mean vacuum, if you haven't got that already.

 

[OSS]

This is a real problem

Don’t get anxious. This is just a problem to be solved and you can do it. I bet if you installed a new catalytic converter, it might save the day — and you need a new one anyway. They definitely don’t last forever and yours is going on 40 years!
It needs to be replaced- if not this year, soon.

Since your NOx is passing, your EGR system is working good enough. Just gotta make sure the air injection system is to spec - and I bet you’ll pass (maybe with a new cat).

 

[DieselFJ]

Don’t get anxious. This is just a problem to be solved and you can do it. I bet if you installed a new catalytic converter, it might save the day — and you need a new one anyway. They definitely don’t last forever and yours is going on 40 years!
It needs to be replaced- if not this year, soon.

Since your NOx is passing, your EGR system is working good enough. Just gotta make sure the air injection system is to spec - and I bet you’ll pass (maybe with a new cat).

Thanks, I’ll work the AI system this weekend and place an order for a new cat. Quick question, I’m running an air pump from a ‘79, the body is smaller. Does anyone know if there was an output difference between years?