[dogboy2]

O.K., here's a collective head scratcher I could use a little help with. The '60 is not passing emissions but just barely not passing. It's FAILING by 2% for CO on the high speed (2500 RPM) test. It is PASSING beautifully on all other components of the test proceedure. Oregon uses a sniffer now, no dyno.

Here's the current state of the truck:
• Jim C. carb rebuild in June of this year
• complete tune-up with new plugs, cap & rotor, oil & filter, PCV valve, freshly cleaned K&N air filter, timing and idle speed to spec, sans valves (adjusted 4K miles ago), plug wires have 7K miles on them
• EGR valve, EGR modulator, and BVSV's: new 7K miles ago
• Smog pump and hoses: brand spanking new (50 miles)
• CAT: brand new MAF high flow (50 miles)
• vacuum lines: 50% new

For what it's worth:
• truck passed brilliantly without question 2 years and 7K miles ago, before the carb was rebuilt
• truck runs better than ever before and gets better gas mileage since the carb rebuild....purrs like a well oiled sewing machine and pulls like a demon, like new...

2% is all I need.... where do I look at this point?
• distributor not advancing properly?
• ignition coil not producing enough juice/weak spark?
• increase plug gap slightly over Toyota spec?

Any and all input greatly appreciated,
Thanks in advance,
-dogboy- '87 FJ60

[Mark W]

Jim knows the ins and outs of the emissions stuff better than I do. But my first thought would be that merely bumping the initial timing a bit ahead of factory spec should probably get you the 2% that you need, no problem.

try setting it at 13-14 BTDC.


Might not hurt to double check your valve adjustment.

What are your other numbers (HC and CO at idle and at 2500)?

Mark...

[dogboy2]

Originally Posted by Mark W

Jim knows the ins and outs of the emissions stuff better than I do. But my first thought would be that merely bumping the initial timing a bit ahead of factory spec should probably get you the 2% that you need, no problem.

try setting it at 13-14 BTDC.


Might not hurt to double check your valve adjustment.

What are your other numbers (HC and CO at idle and at 2500)?

Mark...

Mark,

Thanks for the quick reply, I appreciate it. Here are the test results you asked about:

@ IDLE:
HC = 14
CO = 0

@ 2500 RPM:
HC = 102
CO = 3.1

OREGON EMISSIONS STANDARDS (@ IDLE & 2500 RPM):
HC = 220
CO = 1

As you can see, it is extremely close to passing and is well within the permissable standards on all other parameters.

Any other thoughts?
-db-

[FJ40Jim]

First, a couple of assumptions:
Engine is fully warmed up.
Cat is lighting off. (check inlet vs outlet temp w/ IR gun)
Air cleaner cold air snorkel is intact.

Suggestions:
Try advancing timing per Mark's suggestion.

Adjust mixture screw in until you feel/hear engine start to slow or stumble. Probably 1/2 to 1 turn in.

Add some more "guarantee to pass" additive to a tank of 87 octane. The alcohol in the bottle adds oxygen to the fuel which will increase the CO2 and decrease CO.

Try a clean, dry Nippondenso filter element. An oily K&N will add some fuel to the incoming air, and possibly restrict airflow if it is over-oiled. Both things increase CO.

Pull vac hose off air cleaner door, stuff a BB in hose, reinstall. This will give full time cold ram-air, which adds O2...
Remove BB for driving in winter.

[dogboy2]

Originally Posted by FJ40Jim

First, a couple of assumptions:
Engine is fully warmed up. Yes: typically run it hard on freeway for about 30 minutes prior to testing
Cat is lighting off. (check inlet vs outlet temp w/ IR gun) I suppose it's dangerous to assume that it is working just because it is brand new huh?- will verify with IR gun
Air cleaner cold air snorkel is intact. Affirmative...

Suggestions:
Try advancing timing per Mark's suggestion.

Adjust mixture screw in until you feel/hear engine start to slow or stumble. Probably 1/2 to 1 turn in. Is this the same as the idle speed adjustment screw or is it the one that's supposed to receive the metal plug after adjustment?

Add some more "guarantee to pass" additive to a tank of 87 octane. The alcohol in the bottle adds oxygen to the fuel which will increase the CO2 and decrease CO. Local custom favors a couple of gallons of denatured alcohol to a couple gallons of gas - same result without engine harm?

Try a clean, dry Nippondenso filter element. An oily K&N will add some fuel to the incoming air, and possibly restrict airflow if it is over-oiled. Both things increase CO.

Pull vac hose off air cleaner door, stuff a BB in hose, reinstall. This will give full time cold ram-air, which adds O2...
Remove BB for driving in winter.

On top of the air horn, directly above the Air Control Valve right? Not at the HIC valve?

Jim,
Thanks much for all of the suggestions. I am assuming that these tricks are sequential and cumulative, i.e. try the timing first and then progress through the others if the previous step didn't do it, adding each successive step to the previous one until all of the above are in effect?

I'll give it a shot and report back. Still can't believe it's not passing when it's running so frickin' good and strong but what do I know...

Thanks again,
-dogboy- '87 FJ60

[Pin_Head]

Is your air pump actually pumping air?
If all else fails, you could install a smaller primary jet.

[dogboy2]

Originally Posted by Pin_Head

Is your air pump actually pumping air?
If all else fails, you could install a smaller primary jet.

It's a brand spanking new OEM Toyota part and for the small fortune it cost me, it better well be working.

-db-

[FJ40Jim]

QUOTE=dogboy2:
Originally Posted by FJ40Jim
First, a couple of assumptions:
Engine is fully warmed up. Yes: typically run it hard on freeway for about 30 minutes prior to testing
Cat is lighting off. (check inlet vs outlet temp w/ IR gun) I suppose it's dangerous to assume that it is working just because it is brand new huh?- will verify with IR gun
Yes, brand new parts are always suspect, because they are not yet proven to work.
Air cleaner cold air snorkel is intact. Affirmative...

Suggestions:
Try advancing timing per Mark's suggestion.

Adjust mixture screw in until you feel/hear engine start to slow or stumble. Probably 1/2 to 1 turn in. Is this the same as the idle speed adjustment screw or is it the one that's supposed to receive the metal plug after adjustment?
We don't need no stinking plug!
Yes, the mix screw is at base of carb, by valve cover.

Add some more "guarantee to pass" additive to a tank of 87 octane. The alcohol in the bottle adds oxygen to the fuel which will increase the CO2 and decrease CO. Local custom favors a couple of gallons of denatured alcohol to a couple gallons of gas - same result without engine harm?
If you want to put large quantities of alcohol in, use E85 fuel, not paint thinner. At least E85 is tested and certified to be clean & dry.

Try a clean, dry Nippondenso filter element. An oily K&N will add some fuel to the incoming air, and possibly restrict airflow if it is over-oiled. Both things increase CO.

Pull vac hose off air cleaner door, stuff a BB in hose, reinstall. This will give full time cold ram-air, which adds O2...
Remove BB for driving in winter.On top of the air horn, directly above the Air Control Valve right? Not at the HIC valve?Yes, right on top where it's easy to get to.

Jim,
Thanks much for all of the suggestions. I am assuming that these tricks are sequential and cumulative, i.e. try the timing first and then progress through the others if the previous step didn't do it, adding each successive step to the previous one until all of the above are in effect?

Not really sequential, but cumulative, yes. Just a random list of suggestions to get you over the hump.

I'll give it a shot and report back. Still can't believe it's not passing when it's running so frickin' good and strong but what do I know...

Thanks again,
-dogboy- '87 FJ60

[Toadhopper]

Have you checked to make sure the VSV #1 is working properly?
Mine wasn't and my AI was stuck in bypass mode.
You can check easily by making sure the bypass hose on the air cleaner isn't putting out any flow at idle.
Once mine was fixed it lowered HC and CO emissions quite a bit. If you've just replaced the CAT (and its working properly) the emissions should be lower than they are. The cat could be masking an existing problem like the bad VSV.
Toad