Quick carb question-slow idle cut off 2f (1 Viewer)

[FJ40Jim]

It looks like the dist vac advance is connected to one of the 2 ported vac fittings. They will show no vac at idle, but will make vac when driving at part throttle.

The other hose on carb base is connected to the HAC fitting. Nothing should be connected there.

CB gets vac from the center fitting on air horn.

 

[houstonfj40]

It looks like the dist vac advance is connected to one of the 2 ported vac fittings. They will show no vac at idle, but will make vac when driving at part throttle.

The other hose on carb base is connected to the HAC fitting. Nothing should be connected there.

CB gets vac from the center fitting on air horn.

So Jim, my choke break should be to this port here, I also think I am missing a vsv in-line also for the choke break. Thanks again! Happy Fathers Day

 

[FJ40Jim]

The VSV isn't important. Earlier trucks & non-US don't have one.
Just get a vac hose in there.

 

[houstonfj40]

So my issues seems to have gone away now that I connected my choke opener to a vacuum source. On a desmogged, where should the choke opener be connected via vac hose. This is what I’d did temp and not rich now.

 

[Infinity00]

I can’t tell exactly where you have it connected but it looks like to the float vent? On a desmog if you removed the pink thermo vacuum valve and don’t want to use the choke opener then it gets routed directly to any of the 3 vent ports on the air cleaner cover. That’s how most people do it. If you want it functional check out @mwebfj60 desmog page. It shouldn’t be hooked to the float vent. That’s where the charcoal cannister should be hooked to.

 

[Infinity00]

Oh I see where you have it routed to the place the choke break is supposed to go. Put the choke break there and route your CO to the vent in the air cleaner that you have plugged with the red caps - just be smart enough to push the choke in when you are warmed up

 

[houstonfj40]

Oh I see where you have it routed to the place the choke break is supposed to go. Put the choke break there and route your CO to the vent in the air cleaner that you have plugged with the red caps - just be smart enough to push the choke in when you are warmed up

Evilorgoodtwin,

I am doing a little testing this morning. The way it is set now gets rid of my issue. The vacuum actually pulls on the CO. Is there actually vacuum at the air cleaner? I guess there is enough there to actuate the CO at throttle? Just atmosphere at idle. Thank you.

Marc

 

[Infinity00]

There is no vacuum at the air cleaner ports I’m referring to. The correct place to put it if you want it working correctly is the pipe that goes to the pink thermovalve, the bottom valve, on your thermostat housing. This way it will only pull off the choke when it warms up. The way you have it now, it pulls the choke off before it is warm. If your choke is working correctly, you shouldn’t need it. Yes it helps slow your motor down and lean it out when you’re warming it up in the morning but if you’re like me, I only have to pull out the choke to start it and then I push it in 4/5th of the way back and let it warm up like that. If you’re in Texas, does it get down to 50s at night? Do you need your choke to start it?

 

[Infinity00]

It seems like your vacuum lines might be missing and/or messed up. Take a picture of the engine bay from a few angles and we can get you sorted out. For example, the fuel cut port on your carb isn’t hooked up, and if you don’t have the fuel cut solenoid mod done, you will have a stumble or engine cutting out when you come to a stop sign or off a highway ramp. And if you hook the vacuum line to the pink valve, I’m not sure the other side of the pink valve is hooked up correctly. If you do get the city racer carb to swap in, it’ll only have one vacuum port on it to advance the dizzy, the choke break and choke opener aren’t on it. They aren’t needed either! You just have to operate you’re choke manually like it was done in the old days! Not a big issue. So if getting your choke opener on a vacuum pot is making it run better, you have an issue with the choke opener plate not opening all the way (and that doesn’t make complete sense to me but I’ll go with it).

Take the air cleaner too off and look at the plate with the choke lever pulled all the way out, the plate should be completely closed. Push the choke lever all the way in and the plate should be all the way open and in the vertical position - 90 deg - no less than that. If those two things check out you are pretty much good there if you manually operate your choke lever while it’s warming up, I.e., the CB and CO aren’t needed but are a nice addition. To check your CB and CO, pull your choke lever back out, plate is closed and take a known good vacuum line and apply a vacuum to the choke break and see if it breaks the plate open a tiny bit, hold the vacuum and make sure the vacuum doesn’t leak past the diaphragm. Let the vacuum off and do the same thing with the choke opener, the arm on the side of the carb should pull the plate open, hold the vacuum and make sure it doesn’t leak past the diaphragm. If these things check out your choke system is good. I’ve written this from memory so I suggest your look at the FSM and follow it. It’ll show you the vacuum routing for everything as well.

 

[houstonfj40]

Working off a PO desmog done by ACC. They were not using the A/C idle up and I need that here in TX. No, really do not ever need the choke to warm up, just gain a little RPM when warming. I hooked up this way and everything worked fine for about an hour of driving this morning. No longer any pink valve on housing. Ever since I did put a little vac on the CO, it has run great. Now it is run to the air cleaner. Maybe valve was stuck because I had a rich and Dru Le issue off idle when ac idle up was on. I think there are a few other things done in a way which is not by the books in desmog. Project just getting started.
I think there are issues with eBay system as seems to be hooked up wrong an one of the multiple tubes at vent system by tank has been removed but zip tied there. My vent on dist has also been capped.
Coaching an 11 yr old baseball team now so time is in short supply.
Thanks for the help!
I am also trying to locate a dist as the vac advance doesn’t hold vac on mine. All others diaphragms are good elsewhere.

 

[houstonfj40]

 

[houstonfj40]

And my plugs looked this this pre and post the vac line connections on carb as pictured above.

 

[NeverGiveUpYota]

I see no passenger VCV? My truck was run that way when I bought it but I was under the impression it’s necessary so I put one inline. So that means your not hooked up to the HIC up under the aircleaner. Nor is the valve on the air horn hooked up? Do you have a vent line from diz cap to passenger firewall?
Lots of inconsistencies I see there.

 

[NeverGiveUpYota]

Looks like a cap sorta thing is covering the vent line on the diz cap. Someone can send you a photo how it should be plumbed to the firewall. I’m at work so I can’t right now.

 

[NeverGiveUpYota]

Putting a VCV in-line will hook up these capped areas plus two more I believe.

 

[NeverGiveUpYota]

How much drive time are those plugs? Dirty changed to new? Few miles? Or say 2k plus?

 

[houstonfj40]

On the new ones, about 30 miles. But when I first installed the looked like others after 5. The two vac lines on carb seem to have solved richment issue. This all started as a lean drop carb adjustment. My issue is solved right now and I may just run it for a while before tackling the other “doesn’t seem right” stuff. It’s all vac lines and vent lines in engine bay rest of truck spot on. I get in trouble when I attemp to “correct” things. Your carb should be here today, @HemiAlex just pulled in.