ABV/VSV smog help

[Marc311]

After failing smog and the re-test (High CO), I began troubleshooting per the emissions manual. I stopped at 11 pm, but here is what I know so far . . .

The AI system is in bypass mode. The first thing the manual says to do is check this to make sure air is not being pumped into the bypass hose - But it doesn't say what steps to take next! This does explain my high CO numbers and my relatively high (albeit passing) HC numbers.

I also know my EGR VSV is bad and I haven't yet checked the AI VSVs but I'm guessing one or both may be bad as well. SOR lists these for about $40 used and $70-$100 new. I know CDan can do better, but it still won't be cheap.

Any ideas as to why it is in bypass right off the bat? (I should know more tomorrow about the other two VSVs). In addition, is there a good source for VSVs or are there other replacements? Some posts talked about celica and camry VSVs, but were pretty vague. Thanks for the help.

 

[Dave-T]

After failing smog and the re-test (High CO), I began troubleshooting per the emissions manual. I stopped at 11 pm, but here is what I know so far . . .

The AI system is in bypass mode. The first thing the manual says to do is check this to make sure air is not being pumped into the bypass hose - But it doesn't say what steps to take next!

You are using the factory emissions manual? It spells out the procedures in great detail. If the AI is constantly in bypass, Your ASV may be stuck open.

 

[Marc311]

Yes, I am using the FSM. In the section regarding the AI system the steps are as follows:

1. Visual check
2. Disconnect the air bypass hose from the air cleaner
3. Start Engine
(so far so good - then it starts with the VTV and ASV check)

4(a) With engine idling, check that air is not discharged from the bypass hose
4(b) disc. vac hose from VTV and check that air is discharged from the bypass w/in 3-10 seconds.
4(c) Reconnect and check that it stops quickly
5. Checing the ABV
etc.

As you can see, I get to 4(a) and have found a problem and obviously can't check 4(b). What is not clear is how to diagnose that problem. There is no flow chart type if/then to say what to do when you have a problem. I am taking a small leap of faith, since the VTV gets vacuum from VSV(1), that VSV(1) may be the problem. I have not yet tested that VSV.

And I guess that leads me to my question: Should my next step be testing VSV(1) and if it is bad call it done or am I missing something else that could be causing the ABV to go into bypass mode - i.e. the ABV itself is stuck open for some reason. The FSM has been very helpful, but I am still a little foggy as to how the whole AI system works. I know others on this forum have been down this path and are far more familiar with the AI system and can hopfully lead me in the right direction.

I want to follow the procedures as outlined in the FSM so I don't skip over something. But obviously the FSM isn't clear at this point - at least to me.

My apologies in advance to everyone for all these acronyms.

 

[Marc311]

In looking at the pretty picture in the FSM of condition 4 (air bypassed to the air cleaner) it looks like for this to occur both the ABV and ASV must be closed (which seem to be their natural state). The ASV should always be closed with the cat temp below 1445 degrees.

So, from what I can tell, the ASV is stuck closed because either VSV(1) is not giving it vacuum to open it or the valve is stuck (due to it sticking or an obstruction).

I apologize for thinking out loud here, but would love some feedback.

So my plan is to test VSV(1) to see if I am getting vacuum. If so, the ASV must be bad. If not, the VSV may be bad. I will put vacuum on the ASV and see if I can get it to open.

Thoughts?

 

[Dynosoar]

Did your air pump ever die? Do you have a leaking power steering pump? If you answered yes to either of those questions then you may have a piece of the carbon vane from the pump stuck inside the ABV. If yes disassemble clean and reassemble. The good news is there are no small or complicated parts just four screws.

Dynosoar

 

[Marc311]

Thanks Dynasoar.
When I bought this rig, the PO had given up on it after the smog pump froze and his mechanic gave up and returned it to him missing numerous pieces. So who knows how much of the smog pump imploded into the system as I never saw the previous pump.

A little update. VSV(1) is not working. I bypassed it and put the vacuum directly onto the ASV and it did not take it out of bypass. I was only reading about 10 on that vacuum line. I was able, using a vacuum pump, to manually get the ASV out of bypass. So the valve at least opens and closes, but it seems to need more vacuum than the line can supply.

I am wondering if I can just recondition the ABV. It's really that easy to take apart?

Anybody know a good (and cheap) source for VSVs?

 

[Dave-T]

I am wondering if I can just recondition the ABV. It's really that easy to take apart?

It is easy to take apart. I found a lot of junk in mine when I took it apart. I also replaced those stupid philips head screws with hex head bolts.

 

[Dynosoar]

Use a impact driver to remove the screws.

 

[Dave-T]

Use a impact driver to remove the screws.

Good tip, I use one. Still a pain imo.

 

[AfricanToy]

Good tip, I use one. Still a pain imo.

any pics of the procedure?

 

[Toadhopper]

Thanks Dynasoar.
When I bought this rig, the PO had given up on it after the smog pump froze and his mechanic gave up and returned it to him missing numerous pieces. So who knows how much of the smog pump imploded into the system as I never saw the previous pump.

A little update. VSV(1) is not working. I bypassed it and put the vacuum directly onto the ASV and it did not take it out of bypass. I was only reading about 10 on that vacuum line. I was able, using a vacuum pump, to manually get the ASV out of bypass. So the valve at least opens and closes, but it seems to need more vacuum than the line can supply.

I am wondering if I can just recondition the ABV. It's really that easy to take apart?

Anybody know a good (and cheap) source for VSVs?

Try checking the VSVs independently per the FSM.

 

[dogboy2]

First of all, you are on the right path by utilizing the FSM. It is single handedly the best resource for troubleshooting and diagnosing your truck. Solid decision, stay the course.

Second, your AI is in by-pass mode as per Diagram #4. The VSV(1) regulates function of the ASV which controls air passage to the exhaust (open position) or to the air bypass hose (closed position). Test your VSV(1) as per the FSM - chances are good that it is not functioning. Replace with new if it specs out bad and re-test step 4(a).

If that doesn't work, you are going to have to test each component of the AI system individually as per the FSM. It's not difficult, just a little time consuming. You will find the problem(s)

Stick with the OEM VSV's. Pricey at full retail but they are designed for your vehicle and will most likely last another 20+ years.

When it comes to high HC, don't overlook the condition of your carburator, basic tune up items (spark plugs, plug wires, PCV valve, air filter, fuel filter, cap and rotor, oil and filter), and the other parts of your emission system (spark control, air pump, OC sensor, CAT). Start with a full FSM tune up and then troubleshoot your emissions equipment. Barring a complete tune-up and a full functioning emission system, your carb may need to be rebuilt -- Jim C. does a great job.

HTH,
-dogboy- '87 FJ60

 

[Marc311]

Yes, I am in condition 4 (see my earlier posting about finding the pretty picture in the FSM). And VSV(1) was tested and not working (again, see previous post). So I am totally with you on that and have ordered replacement (used) VSVs. It is my understanding they are no longer available new (although there may be a celica substitute for VSV(1)). I also have not confirmed that with CDan. SOR has them listed, but they are around $100

I direct fed the vacuum line (i.e. bypassing the switch) to the ASV and it was not strong enough to open it. I was able to get it to open using a vacuum pump. It has probably been sitting closed for who knows how long so I am hoping I can just exercise it a bit to get it to open a little easier. I am wondering if I could lube it. I'm not really sure how hot the air in those hoses get. But I am worried that even with a properly functioning VSV, the ASV may be too sticky too open.

I tried to open the ABV, but without an impact driver I am just stripping the phillips head screws (good tip about replacing them with hex heads).

So I think I know what I need to get this thing to pass smog. What I am not sure is if my ABV is in good enough shape. Those things are like $700 new and pretty expensive used as well. If necessary, I might just route the pump directly to the manifold. I only need the thing to pass smog for four more years, but I would like to keep it environmentally friendly after that.

 

[dogboy2]

Yes, I am in condition 4 (see my earlier posting about finding the pretty picture in the FSM). And VSV(1) was tested and not working (again, see previous post). So I am totally with you on that and have ordered replacement (used) VSVs. It is my understanding they are no longer available new (although there may be a celica substitute for VSV(1)). I also have not confirmed that with CDan. SOR has them listed, but they are around $100 .

Marc311,
I just lived this exact scenario with our '60, so I feel your pain. Failed Oregon's emissions test 5 times on high HC before I solved the problem and that was with a Jim C. rebuilt carb, fresh tune-up, new smog pump, and new high flow CAT.

The VSV's are still available new through Toyota. Retail is, as you mentioned, around $100.

In my circumstance, once the VSV(1) was replaced, the AI system was taken out of by-pass mode and I was able to proceed with the subsequent test protocols in the FSM. Fortunately this was the last piece of the AI system that needed attention and the truck passed smog brilliantly once replaced.

While you are still stuck in by-pass mode, you might want to verify if your HAI is functioning. Mine wasn't although the individual components of the HAI system were fine. Turns out that with the AI in by-pass mode at startup, the HIC valve was never getting hot enough to function and drop the air control valve. The engine was receiving a constant charge of hot air and subsequently was running a bit richer than it should, bumping up my HC's. Once the AI was functioning properly, the HAI system immediately began to function as designed and my HC's dropped (verified this before and after with a Snap-On tailpipe gas analyzer). And as predicted by the tool, the truck then passed beautifully.

HTH,
-dogboy- '87 FJ60

 

[Marc311]

Good info DB2.

I bypassed VSV(1) and managed to get the ASV to stay open. Since I took the day off and my registration is now expired, I decided I would try to pass as is so I can at least get the registration current. I figured, given my numbers, the air pump actually blowing into the exhaust would get me by. Well, no.

Although my numbers were better, I still am not close to passing CO. (allowed is 1.18/1.52 and I had 1.9/2.01). My HC passes, but they are higher than they should be. The smog guy said the numbers generally indicate a rich condition, most likely the carb, but could also be the cat. He also wondered if there was a choke issue. My choke cable IS broken, but it is stuck open, not closed.

I will check the HAI as you suggest. Maybe it will be that simple. if that doesn't work, my plan is as follows: I am going to borrow a friend's JimC rebuilt carb (his 60 is out of commission for a bit) and I am going to get a new cat. After that I will either shoot the truck or myself - depending my mood.

 

[dogboy2]

Although my numbers were better, I still am not close to passing CO. (allowed is 1.18/1.52 and I had 1.9/2.01). My HC passes, but they are higher than they should be. The smog guy said the numbers generally indicate a rich condition, most likely the carb, but could also be the cat. He also wondered if there was a choke issue. My choke cable IS broken, but it is stuck open, not closed.

I will check the HAI as you suggest. Maybe it will be that simple. if that doesn't work, my plan is as follows: I am going to borrow a friend's JimC rebuilt carb (his 60 is out of commission for a bit) and I am going to get a new cat. After that I will either shoot the truck or myself - depending my mood.

Fun and games isn't it? Don't shoot the truck, you'll regret it .... just kidding - trying to inject a little levity into an otherwise utterly frustrating situation.

No insult intended to your process but I have to ask: have you taken the base variables out of the equation, i.e. completed a full tune-up including a valve adjustment as per the FSM? Replaced the basic tune-up items like spark plugs, cap, rotor, air filter, PCV valve, fuel filter, oil and filter? Timing and idle speed adjusted to spec? No vacuum leaks anywhere? Cleaned the carb internals with a liberal bath of carb cleaner?

Those who are much wiser than I could better explain a little trick of using an IR temperature gun for testing the CAT before you go and replace it carte blanche. IIRC, you take a reading before the CAT and after the CAT - the exit temp should be higher than the entry temp, but don't quote me on that - will verify tomorrow and post back.


-dogboy- '87 FJ60

 

[Marc311]

I just gave it a full tune up (minus the PCV which I will do shortly). I have not adjusted the valves yet and I am sure it likely needs it so I will have to find some time for that. But the basics (cap, rotor, plugs, wires, oil, filter, fuel filter, air filter have all been done and it has all new vacuum tubing.)

That being said, I played around with it some more based upon your earlier post and it appears the HAI I staying open. I still need to investigate further, but it was pretty well warmed up and the valve wasn't dropping. I have not yet tested the HIC itself - I just observed what was happening. That being said, I wonder how much that effects emissions. It certainly seems preferable to have nice cool air flowing in there and I am sure the air is a bit constricted flowing through the HAI, but would it make it that much richer?

 

[billstoyshop]

I have found in many cases that vsv's fail- hoses are hooked up wrong-and vehicles are out of tune. but it looks like you have covered your basics on these. Check the VSV under the air filter housing(above the distributor) This VSV is for the distributor dryer but a blown diaphragm in the vsv can cause a vacuum leak and shut down the abv as they share vacuum. If thats ok pull off the relief valve near the abv and test it for air flow(blow through it) if any air can pass through the single port at the end of the canister out to the bottom two ports its toast.I have been able to tap on these by-pass valve and clear then of carbon and get them to seal once in a while. Remove and test your air injection check valves when you replace the abv or if you find carbon in the abv relief valve. Remember the relief valve is there to protect the air pump from overloading if the air injection system becomes clogged. Since the air pump is the only belt running the water pump you can see the problem that could happen if the air pump could not have some sort of relief. good luck Bill

 

[Marc311]

It seems almost everything in the emissions system is toast. Both of my VCVs (distributor vent and evap system) are bad. Not sure how much those two effect emissions, but I guess I will replace them all the same. The car is running pretty well so I am a bit surprised as to all the bad components (or had the PO got it to pass the last time). I have all three VSVs on order and now I will be ordering two VCVs. I took apart the ABV and cleaned it up. At least it seems to be okay. I also need to figure out my HAI system as the flap which diverts hot air to the carb is staying open. When will it all end???????

 

[billstoyshop]

Replacing the vsvs will help on the emissions and may bring other systems in line. Also the vsv's that leak will kill your gas mileage by dropping your available vacuum and turning on the power valve curcuit in the carb to soon. Keep up the faith on this project, most of the stuff you replace wil last a very lomg time. Your getting close to finishing. Good luck Bill ( Toyota master Tech)