Almost ready for smog but...

[Stoffregen Motorsports]

On 5/24/2023 at 7:14 AM, A guy named Rick said:

I attempted smog again and my truck is now classified as a gross polluter. It ran severely rich, worse than the first time. Second time was lean once I realized the idle switch wasn't activated because the little spring came off. This time I tried another carburetor I rebuilt but I forgot Vac switches A and B were plugged. I believe this caused it to run in open loop, and the mixture solenoid jet is larger on this carburetor resulting in an even richer mixture than before.

 

I need some help understanding Vac switches A and B. When connected is when the idle will go up and down a tiny bit, which is not a problem, it's not by much at all. The problem is taking off and when around town I let the gas pedal go and start accelerating again it's often jerky in the lower ram's until the idle switch is off above 1500. I understand there is a fuel cut function for the idle circuit, why is it doing something when still on the idle circuit? 🤔 it runs fine in the running circuit. I'm wondering if the idle cut solenoid is partially activated at idle? My understanding is if I leave it plugged, the computer thinks it's under WOT and will be in open-circuit, per the FSM. If I have it connected, it's very annoying around town. My next guess is float level, but this doesn't make sense to me because in open-circuit it idles and runs perfect. Just that it's insanely rich. I'm out of ideas 💡 

Don't you have a test only station nearby? I wold not have gone all in until you knew it was ready.

[A guy named Rick]

18 minutes ago, Stoffregen Motorsports said:

Don't you have a test only station nearby? I wold not have gone all in until you knew it was ready.

Went to a test only. You mean one I can pre-test? Looking into that.

 

I had one give me shit for having a different VIN on my dash because previous owner swapped it (not the cluster though, judging by my vin history report I had showing mileage at various points through the years) saying I need a vin verification when the door jam and engine bay vin tags both are what's on my registration.

[datzenmike]

SMH California. Jeezus.

[720_Jeff]

According to my smog guy, in California there is no longer a pretest.  All results get transmitted to DMV.  You get it wrong, then you might get the gross polluter label on your vehicles record 😞

 

[Stoffregen Motorsports]

46 minutes ago, 720_Jeff said:

According to my smog guy, in California there is no longer a pretest.  All results get transmitted to DMV.  You get it wrong, then you might get the gross polluter label on your vehicles record 😞

 

Hmm, that must be new.

 

Yes, CA really bites the big one on shit like this.

 

VIN verification - yeah, you're numbers need to match. But that's anywhere in North America.

[720_Jeff]

Looking further, on CA BAR site, seems there is a unofficial test.  Could be a misunderstanding by my smog guy, or who knows.  I do recall what he told me, though.

 

Suppose, you can ask the smog guy, if it gets transmitted to DMV/BAR, and if so, what are the consequences.  Not sure how one verifies the answer given is the actual facts or also a misleading answer.

 

What is a pretest?

A pretest, or pre-inspection, is an unofficial test performed by a station to help identify emissions-related problems prior to an official Smog Check. Following a pretest, the station will provide a vehicle inspection report showing the vehicle’s results; however, a smog certificate will not be issued. Stations may charge for this service and must obtain consumer authorization before performing the pretest.

 

https://www.bar.ca.gov/consumer/smog-check-program/faq#:~:text=A pretest%2C or pre-inspection,certificate will not be issued.

[A guy named Rick]

Well I swapped back to the O2 sensor that was in before replacing it, runs better. OK, still stumble and hesitation off idle, not so bad though. Choke flap is gone for now, so choke not on. Idle switch adjusted fine. No vac leaks. Float level brought up a bit. If I have foot light on pedal in say 2nd gear like 15 maybe 20mph you can feel it bucking. At a stop, revving engine can hear rpms up and down a bit, can hear misfiring every now and then. But it runs awesome putting your foot down. Pulls pretty well. It's just the low speed circuit/idle circuit whatever messing me up. 

Datzenmike always says coils don't misfire, they work or don't. How about ignition control module? 

This shit is pissing me off.

[720_Jeff]

One of mine, is doing something somewhat similar.  It will idle @around 800-900 by the factory tachometer.  Sound about like that as well.  As I'm driving it, idle will creep up to maybe 1000-1100.  In fact, I can hear/see it rising, just idling if stopped at a traffic light long enough.

 

[A guy named Rick]

I can take the top off with it on the carb, and I have 2 spare MC solenoids laying around. If I were to swap out and crimp some spade terminals on, would that work or does it need a good solid butt connector crimp job? I don't have the tool to get the wire out the big connector so I'd probably just cut and figure quick connect terminals would work. Who knows, maybe the solenoid isn't correct for the ECC module on this truck. 

[720_Jeff]

I hate cutting things, I'd lean on

 

https://www.amazon.com/Depinning-Electrical-Connector-Extractor-Automotive/dp/B0922GF9W8/ref=asc_df_B0922GF9W8/?tag=hyprod-20&linkCode=df0&hvadid=507909731226&hvpos=&hvnetw=g&hvrand=15823206693415742391&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9031527&hvtargid=pla-1290138230576&psc=1

Edited May 27, 2023 by 720_Jeff

[jagman]

I had the bucking problem and a backfire issue that was solved by replacing the fuel filter. But last week I began hearing a ticking sound coming from the engine. It turned out that the timing chain flat guide had broken off and was jammed in the timing case.  I have no idea why the prior problem caused the broken guide.

[Thomas Perkins]

Just maybe,like real soon.California will break apart and float out to sea and sink.Then,New York does it to.Then we build a wall around Georgia to make sure we stay red.

[A guy named Rick]

5 hours ago, Thomas Perkins said:

Just maybe,like real soon.California will break apart and float out to sea and sink.Then,New York does it to.Then we build a wall around Georgia to make sure we stay red.

Not here to discuss politics.

[A guy named Rick]

5 hours ago, Thomas Perkins said:

Just maybe,like real soon.California will break apart and float out to sea and sink.Then,New York does it to.Then we build a wall around Georgia to make sure we stay red.

And then the we will lose the largest agricultural producer in the US.

[Stoffregen Motorsports]

8 hours ago, A guy named Rick said:

Not here to discuss politics.

Good. Thank you.

[A guy named Rick]

Yesterday decided to unscrew the mixture screw and shoot some carb cleaner in there. Apparently when I did the carburetor rebuild, I did not clean out that port. The spring was pretty nasty, the needle tip of the screw wasn't really bad. I couldn't get around a driving at last night so I drove at this morning to get some gas and throw some Techron in. It ran great! Until I realize that I had left the line undone that T's into the EGR off the curved port that's on the bottom section of the carb near the mixture screw. So obviously I hooked that back up and then it goes back to stumbling a bit off takeoff. So, EGR opening is giving me the issues!

 

So, if the EGR is what's giving me problems, the BPT is working... however, is it POSSIBLE that the BPT can be overactive? Hence, plugged catalytic converter?? Or is it possible the BPT is just a bit over sensitive? Maybe, just maybe, I can throw a restriction orifice in it like what a few of the vacuum lines have?? I figure the BPT would be a "it works or it doesn't" type of thing.

[A guy named Rick]

I need to do some more testing but seems like it might possibly be my charcoal canister valve causing a vacuum leak. It makes sense why when undo the vacuum line for EGR off the carburetor base, it shares line with the smaller line to the canister and runs better unhooked. I was messing around under the hood yesterday and unhooked the line to the canister from the T connection and plugged it with my finger, revved the engine a bit and heard air hissing on driver's side. So I squeezed the bigger line and it stopped. The bigger line is the one going to the fitting on the intake manifold that which is a big port with 2 smaller ports, the bigger one going to the AB valve.

 

Per FSM if you suck air on either of the 2 ports on the vapor canister, no air should escape. The top one with smaller line a very small amount does. The bottom port with the larger line leaks a good amount (using vacuum hand pump with gauge, can get to -20inHg but leaks out in about 3 seconds to 0.

[Stoffregen Motorsports]

Charcoal canisters can get clogged or soaked in fuel. Either way, it may be time for a new canister.

 

You can rebuild them, but it's a lot of work.

[720_Jeff]

They should be easy to find in the JunkYard, although no idea how one would test in the field for a soaked with fuel condition.  Good news, probably pretty inexpensive.

Not sure I've ever seen one missing on a JY 720.

[Stoffregen Motorsports]

Generic charcoal canisters are available anywhere. Just make sure to get the right shape and size and with the proper amount of connections.

 

https://www.summitracing.com/search/part-type/fuel-vapor-canisters

 

https://www.amazon.com/Dorman-911-261-Evaporative-Emissions-Charcoal/dp/B07KFZ1WPW/ref=asc_df_B07KFZ1WPW/?tag=hyprod-20&linkCode=df0&hvadid=330440990362&hvpos=&hvnetw=g&hvrand=2428963525030567368&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9032448&hvtargid=pla-635725856126&psc=1&tag=&ref=&adgrpid=66704631099&hvpone=&hvptwo=&hvadid=330440990362&hvpos=&hvnetw=g&hvrand=2428963525030567368&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9032448&hvtargid=pla-635725856126