More 78 FJ40 California smog woes…

[Gusb]

Stumbling through California smog again (inched through 2 years back). After the carb rebuild and everything running well I’m again a gross polluter. Didn’t do a tuneup or anything before taking it in because the truck has been running great. The tech guy said it almost passed, “maybe lean the carburetor out” and recheck. I had opened the main jet a bit (per Jim C’s suggestion) on the carb rebuild, would that maybe have an effect? I’ve attached numbers from 2012 and yesterday (2014) below. So should I just go through a complete tuneup, try to lean out the carb adjustment, etc. and take it back in or should I also be worried about that opened-up jet? Thanks!

 

[JTeeg]

You could try this....

https://forum.ih8mud.com/threads/smog-hypothetical.798212/

 

[JTeeg]

I think you also need to richen the fuel mixture - a lean AFR will cause high NO. Could also be a vacuum leak, or if you been letting it sit for a while the carburetor may need to be cleaned.

 

[Pin_Head]

it is failing CO, so it is running too rich.

 

[FJ40Jim]

Since it is failing at 1400RPM, the carb is still partially running on the slow circuit. Leaning out the idle mixture screw may get it lean enough to pass.

Or it's hypothetically possible to oxygenate the fuel w/ E85 and get a similar result.

 

[Gusb]

Thanks for the comments - much appreciated. Pin_Head, the smog guy did say it was running too rich. He said he didn’t know much about carburetors but he also thought leaning out the mixture (as Jim suggests) might help. Does that mean I just follow the “Adjust idle speed and idle mixture” steps in Toyota’s ECR Manual or is there a way to adjust it even leaner? And Jim, is “oxygenate the fuel w/ E85” just an additive I would put in the tank - and should I be doing both?

Edit: I think he also said that raising the idle a bit might help - I think it's around the 650 rpm.

 

[skidplate]

Thankfully I'm now exempt ('75), but I always changed plugs, points and rotor, replaced the air filter, and changed the oil. Seems an old smog guy told me to do this, so I did and it seemed to work. Not trying to get political, but it seems after yesterday's election, the majority of kaliforeiners are quite happy living under the thumb of nanny potilitians. I don't see the smog gestapo letting up anytime soon. My .02.

 

[Pighead]

Edit: I think he also said that raising the idle a bit might help - I think it's around the 650 rpm.

Yes. Make the idle 850 or so....

 

[DSRTRDR]

make sure the engine is nicely warmed up before you go in

 

[Pin_Head]

If leaning out the idle mix doesn't cut it and there isn't some kind of weird fuel leak, then the next step would be the next size smaller primary main jet. It is also close to failing at 2500 rPM, so a smaller main jet may be needed.

 

[1Fine40]

E85 is highly ethanol laden gasoline, use very judiciously....it's corrosive as heck to our old rigs carbs & fuel lines. In small quantities, you should be golden, but after you pass, dilute with regular unleaded promptly! (Not sure you can even get non-ethanol fuel in Cali?? Good luck, the old rig is looking great!!

Cheers!


...via IH8MUD app

 

[user42]

Thanks for the comments - much appreciated. Pin_Head, the smog guy did say it was running too rich. He said he didn’t know much about carburetors but he also thought leaning out the mixture (as Jim suggests) might help. Does that mean I just follow the “Adjust idle speed and idle mixture” steps in Toyota’s ECR Manual or is there a way to adjust it even leaner? And Jim, is “oxygenate the fuel w/ E85” just an additive I would put in the tank - and should I be doing both?

Edit: I think he also said that raising the idle a bit might help - I think it's around the 650 rpm.

I'd bump up the idle just a bit, lean out idle a touch, and put in the next size smaller jet (you're borderline failing at 2500rpm). Get it all warmed up and take it in


Man, I'm getting old. I read that statement "smog guy said he didn't know much about carbs" And I thought how the hell can a smog guy not know anything about carbs?? Over 50% of my vehicles have been carb'd, it just strikes me as odd that someone wouldn't know a carb. Of course I am also flabbergasted that there are people who cannot drive a standard transmission. Which then got me thinking about the passing of years, man thanks a lot, you've sure bummed out my Friday.

 

[Gusb]

If leaning out the idle mix doesn't cut it and there isn't some kind of weird fuel leak, then the next step would be the next size smaller primary main jet. It is also close to failing at 2500 rPM, so a smaller main jet may be needed.

Well I did open up the main jet (21251 ID=1.36 --- 21253 ID=1.24 CAL SPEC.) to 1.50 when I rebuilt the carb (per Jim C.'s advise). So maybe I need to go back to a stock Main jet. When I rebuilt the carb they were discontinued from Toyota and I could not find them anywhere. Anyone know a source for jets? Maybe the even leaner 1.24 CA (my truck is Federal with 1.36) would help me through smog?

 

[kevin colton]

I'd bump up the idle just a bit, lean out idle a touch, and put in the next size smaller jet (you're borderline failing at 2500rpm). Get it all warmed up and take it in


Man, I'm getting old. I read that statement "smog guy said he didn't know much about carbs" And I thought how the hell can a smog guy not know anything about carbs?? Over 50% of my vehicles have been carb'd, it just strikes me as odd that someone wouldn't know a carb. Of course I am also flabbergasted that there are people who cannot drive a standard transmission. Which then got me thinking about the passing of years, man thanks a lot, you've sure bummed out my Friday.

I'm right there with user42, wondering why a smog person doesn't understand carbs. I would definitely look for a shop that employs old men who can adjust your carb and help you to pass. That's what my shop does. I have a stock 78 fj40 and a 78 fj40 with a TBI chevy that I took a year and $ 2000 to get smogged. Good Luck, and check the spaghetti vacuum set up for dried, cracked leaky tubes.

 

[Gusb]

This guy is indeed younger but seems pretty knowledgeable. I kind of thought it was nice he wasn’t displaying some pretense of a deep understanding of carburetors. I also think this is a test only/California setup where these guys are not supposed to make adjustments during the actual testing. He really stressed upping the idle, leaning the carb out (said it almost passed) and bringing it back for a free recheck, which sounds like what the carb gurus are saying here. Two years ago another smog guy told me he couldn’t use any tool - even to open the timing mark cover during the test.

I’ve also done the $2k smog repair thing in the past with my old 80 pickup and been around a few old guys that didn’t exactly own magic wrenches. Besides, it’s bad enough being an old fart - don’t tell me I need to look for other old farts for smog.

 

[Pin_Head]

I have a 1.24 in my junk pile if you want it. PM me if you want it. If you are Houdini, you might be able to change it without pulling the carb, but I have not had good luck with that.

 

[Gusb]

Thanks Pin_Head - left you a PM.

 

[Gusb]

Thanks again Charlie but my luck (with the US mail anyway) is not doing so well. Received your envelope today with just a bullet hole where the jet should be, so our jet is probably lying around the post office floor somewhere. I’ll keep searching for another and really appreciate the effort.

 

[Pin_Head]

Oh no. I was thinking about that after I mailed it and I should have taped both sides.

 

[Gusb]

Oh no. I was thinking about that after I mailed it and I should have taped both sides.

Please realize I appreciate the effort. If not for friends like you (and others here on Mud) my enthusiasm for the 40 might have taken a big hit early on.