Well it passed emissions second try! Lean drop FTW! (for the win)

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Joined
Jan 24, 2007
Threads
11
Messages
70
Location
Bristol, Rhode Island
87 FJ60, all smog equipment in place.

As you guys may have read I failed first try. It was running rich (high CO numbers). All I did was tune the carb per the engine manual (lean drop, idle and fast idle adjustment). Easy, takes all of 1-2 hours.

Some History:
This was my first inspection. I've had the truck about a year.
Way before the inspection I had replaced all my vacuum lines. This caused my idle to run fast (no more vac leaking I guess). To compensate I had messed with the idle adjustment screw to get it to idle better but that was it. Truck ran ok but idle was still erratic and if anything too fast. And then it would occasionally not idle at all, it would die. I would have to keep the choke out to keep it from dying when stopping at lights and such. I could also pull out my choke all the way and get up to around 2200rpm.

My first results:

HC PPM IDLE: 74/220
HC PPM 2500 RPM: 59/220
CO% IDLE: 3.46/1.20
CO% 2500 RPM: 2.46/1.20

After the Lean Drop and idle tune:

HC PPM IDLE: 46/220
HC PPM 2500 RPM: 139/220
CO% IDLE: 0.03/1.20
CO% 2500 RPM: 0.51/1.20

So that's it. PASSED! As you can see it's burning less fuel more efficiently and idling slower and better.

I've read a ton of stuff on this site pertaining to this issue. I have yet to see anyone just recommend a carb tune-up. Guys, it may be just as simple as that. No hocus pocus oil changes, almost empty tank, or reroute hoses crap. Just tune your carb. Don't be scared. It's not too bad at all.

https://forum.ih8mud.com/showpost.php?p=2119710&postcount=37

If you've desmogged to try to pass or desmogged and failed, well, I'm sorry but you're SOL. You dug your own grave on that one. So much for resale.

I can scan the procedure if you guys would like, and I can also take some detailed pics if that would help any of you (I'm sure it would).

Cheers!
 
Very happy for you. I am about a month to 6 weeks from going down this same road, so YES pictures etc. would be greatly appreciated. All my smog stuff is there...just don't know yet what works & doesn't. Your experience will be very helpful.

Thanks, John
 
Good to hear you passed.

Kinda surprised the CO came down that much by just adjusting the idle mixture & idle speed. Can you think of anything else you changed or was different about the two tests?
 
Not really.

I did lubricate my choke assembly because once I had the air intake off I noticed it was sticking a bit, but I don't think that was the issue because my choke was working fine before that. It was just kind of hard to pull.

That and the carb adjustment is all I did.

I would just recommend to everyone to do the carb adjustment first. Worrying about all the smog stuff and air intake just seems secondary. I know the knee jerk reaction is to think that if you failed the smog test then it must be because your smog system is bad, but in reality you may have failed the smog check because your fuel system is off. I mean, the fuel is what causes the smog, right.
 
i agree that the carb must be setup properly. however, most of us "lucky" ones who live in california are subject to what is probably the most rigorous smog test in all of the US. no joke...most of us have to run our trucks on dynos which is supposed to simulate what our trucks would be emitting during real world driving. we also get tested for NOX.

glad you passed and oh how i miss the days of the simple two speed idle test and no worries about NOX.
 
I understand.

I know Cali is the hardest. My point is that for anyone having smog issues, start at the foundation. Without a good foundation you're just guessing. Maybe it's obvious to everyone but all the posts I've been reading never mention a carb tune up. I am only recommending that people should start there. It's the foundation of the system and it seems pointless to alter anything else until you know the carb is right.

I first did a valve job. Then I replaced every hose, both vacuum and air. This caused my truck to idle fast (a good thing I think). Once I knew I had no leaks, then I did the carb. I suppose I should have done the timing first too but mine seemed to run ok.

If everyone that has failed or is worried about the smog test says they have already adjusted their carb and then they still have problems, then I'll shut up.

To me, you're wasting money on swapping parts, rigging up hoses, buying gas additives, etc. if you have not first made sure your carburator is correct. I mean really it's free and can't hurt.

I wonder if mine would have passed Cali?
 
It was just luck and the random variation in your engine running conditions. Fidling with the idle mix and speed will have no effect on your CO emissions @2500 RPM. No doubt it idles better now.
 
RS41AB,

Did you drill the cap out with the carb on the rig? If so, how?

By the way, I'm from jamestown, with family still there and in newport. There's a guy in newport who runs a fairly heavily moded '62. Have you run into him?
 
Yes I did

Just took off the intake and basically lay on the engine from the driver side fender. Even in daylight use a utility light to see better. I used a drill and a progression of bits. Then I used air to clean out all the debris. It really wasn't too big of deal and not that hard. I must admit though that as much caution as I used I did still notch the adjustor screw just a bit with the bit. No harm done.
 
I had similar figures on my smog test, and the thing that ended up fixing it was replacing the front check valve (with a napa replacement). I tried to check the rear check valve but couldn't get it off for the life of me. If anyone else has successfully pulled the rear check valve, please clue me in on how. :)
 
I just failed today with high CO. In VA we get tested for HC, CO and NOX at 15mph and 25mph. Of course, my rpm was virtually the same at both speeds, although the load may be a bit different.

Anyway, my CO was 2.00 and 2.47 versus the allowed of 1.18 and 1.52. Hopefully a carb adjustment will show similar results to yours. If not, a friend has a JimC rebuild that may find its way onto my truck for the next test.
 

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