Smog issues - fixed (1 Viewer)

Joined
Mar 4, 2019
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1
Location
Santa Cruz, CA
Hi All-

I've had quite the education cruising this site for the past two years... thanks to you all.

I failed smog (CA) for the first time since owning the rig and figured I'd write down my experience so someone else can learn from it! Thanks to the info on this site, I passed. Here it goes:

'87 FJ60 with 308k on the clock. Original motor, tranny, etc.

Passed emissions with flying colors when I first bought it 2 years ago... Obvious hole in exhaust so I think most of the exhaust gases never actually hit the sniffer. Since then I've done mechanical maintenance- motor mounts, starter, oil leaks, all new vac hoses, etc.

First emissions under my ownership. Failed.
Idle numbers:
HC PPM- 47
CO%- 0.01
CO2%- 15.6
02%- 0.3

2500 RPM numbers:
HC ppm- 63
CO%- 1.95 (this is where I failed)
CO2%- 14.3
02%- -0.2

Time to regroup. I thought high CO meant rich, so I started thinking about how much or how little air was going through the carb. Low O2 meant somthing with the air injection system I thought... Cleaned the air filter, changed oil, etc.

Checked all vac hoses and found that the vac line to the lower port on carb was unplugged on the side towards the air cleaner. Plugged that back in and then the deceleration fuel cut solenoid started working again! I knew that because it would create a little lurch at highway speeds when I gently hit the accelerator. It had gone away for a while but now was back.

Next I used the emissions manual to troubleshoot the VTV's, VSV's, etc. and found the blue VTV was bad. I also found the entire underside of the brass elbow on the output of the ACV that goes to the air injection rail was disintegrated (is this why the residual 02 was so bad?!). I took apart the ACV/ASV/ABV assembly, cleaned everything out, lubed the mechanisms and made sure it all moved when vacuum was applied. Went to Home Depot and snagged a brass plumbing elbow and JB welded it to the ACV. I replaced all the ancient cracked hoses on this system with new ones I made from McMaster Carr. Once that plumbing was done I found the "gas filter" on the intake manifold with the three vac ports that acts as the vacuum source. As soon as I touched it the thing disintegrated in my hand... Ordered a new one, installed, and now I had good vacuum pressure.

Once all this was done I got down to doing some light carb cleaning to address the rough idle. I took out the fuel cut solenoid and sprayed carb cleaner down it, then unscrewed the idle mixture screw and sprayed cleaner there too. I also added a full bottle of seafoam to a full tank to clean out the gunk. The idle really improved after this tank... Then all of a sudden no idle. Pulled out the fuel cut solenoid and found that the o-ring was gone! Looked in the hole and the o-ring was in pieces. Awesome. Do not spray carb cleaner near this o-ring! Ordered a replacement fuel cut solenoid and used the o-ring from that to replace the original. Tried to find that o-ring at a few shops around here but all of them were too thick.

I adjusted idle again using the lean drop method. Perfect at 650 rpms. Thought I nailed it and then once the truck was warmed up the idle would "hang" when I was at a stop light. If I blipped the throttle it would settle back down nicely. Came home and found that the butterfly plate was open quite a bit- I think my idle was just too high. I turned the idle speed screw closed to lower it, close the butterfly, and the hanging idle disappeared.

Went to the special smog shop (because I'm a gross polluter now), left the engine running while I waited, then bam! Tech came in and told me congrats. I Passed!
Idle numbers:
HC PPM- 77
CO%- 0.02
CO2%- 9.8
02%- 7.3

2500 RPM numbers:
HC ppm- 19
CO%- 0.01 (was 1.95)
CO2%- 13.6
02%- 2.4 (was -0.02)

They did say that coming off idle the HC spiked and then stabilized. Is this an indication of a CAT going bad?

Anyways, I passed and promptly had a beer. It had taken me two months between work travel, reading the emissions manual, and cruising the forums.

Now I needed perfection on that idle and I kept tweaking- I would adjust things perfectly with a warm engine, then drive down the road and all of a sudden the decel fuel cut solenoid would act up and I'd get the dreaded lurch at cruise on the highway. I think I've figured out that a rich idle mixture causes this to get worse. As I leaned the idle, and brought up the idle speed with the idle speed screw, this lurching has mitigated but still hasn't gone away.

Any ideas here? Its killing me. I've done the testing on the solenoid and it check out OK.

Learnings from smog hell- This test is really designed to make sure your vehicle is running as it should. Yes its a pain and even asked myself- "should I just sell this damn thing? Look at those happy people with modern cars!" But I can say that the truck is running better than ever and my MPG improved from 10.5 to 12.4.

I'm in the Monterey bay area. Let me know if I can help anyone out.

Reed

Oh here's some pics

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OSS

Joined
Jun 30, 2017
Messages
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Location
Oblivion
Good job! Congratulations! Good deduction going after the air injection system after you saw low 02. As for the lurching, test the vacuum switch with an ohm meter/continuity with & without vacuum to make sure it's working correctly when vacuum is applied. The emissions FSM gives the details.
If your vacuum switch is dead and you can't find another one, ground its electrical wire to body ground and the lurching will go away (if the problem is a faulty vacuum switch).
 

4Cruisers

Supporting Vendor
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Joined
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Messages
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Learnings from smog hell- This test is really designed to make sure your vehicle is running as it should. Yes its a pain and even asked myself- "should I just sell this damn thing? Look at those happy people with modern cars!" But I can say that the truck is running better than ever and my MPG improved from 10.5 to 12.4.
Fully agree. When I moved back to Nevada in '02 my '84 FJ60 wouldn't pass emissions. But after going through all emissions systems per the FSM, I passed. As an added bonus, the FJ60 ran almost as well as when it was new.
 

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