Manual Choke Conversion

[J10_IA]

So I want to switch my automatic choke over to manual. The automatic doesn't open up all the way which is why I think the truck runs so rough when the engine is warmed up.

I was all for switching to the manual choke, unfortunately the automatic one is a "tamper proof" meaning you can't adjust it, let alone take the black cover off, looks like some pop rivets were used instead of screws so I can't easily take it off.

If I were to leave the automatic, I would need to run wiring for the power assist, as the previous owner removed the power assist for whatever reason. normally this would run to the alternator via some means of wiring. Where would I find the stock wiring, and if he ripped that out too, where would I need to connect the choke's power assist to?

Thanks for any help !

:drivin:

[tgreese]

So I want to switch my automatic choke over to manual. The automatic doesn't open up all the way which is why I think the truck runs so rough when the engine is warmed up.

I was all for switching to the manual choke, unfortunately the automatic one is a "tamper proof" meaning you can't adjust it, let alone take the black cover off, looks like some pop rivets were used instead of screws so I can't easily take it off.

If I were to leave the automatic, I would need to run wiring for the power assist, as the previous owner removed the power assist for whatever reason. normally this would run to the alternator via some means of wiring. Where would I find the stock wiring, and if he ripped that out too, where would I need to connect the choke's power assist to?

Thanks for any help !

:drivin:
IIRC if you drill out the rivets, the holes are threaded.

Year/equipment would help with the other questions. It's helpful to put that info in your sig.

[J10_IA]

Thanks for the advice, I added some info to my signature.

Its a 1BBL carter carb, I was thinking of removing the carb and drilling them out, good to know they are threaded before I did so.

[tgreese]

Thanks for the advice, I added some info to my signature.

Its a 1BBL carter carb, I was thinking of removing the carb and drilling them out, good to know they are threaded before I did so.

You sure it's not a 2V Carter BBD? That's what would be original on a 1982 4.2L engine. If you have an aluminum intake manifold, it's a 2V.

Not so sure about the Carter and threaded holes. It's 100% thermal - you need a choke stove and working hot air lines for it to open. You can get a repair kit for the choke stove from the Help! pegs at the auto parts store.

The BBD has some problems, but the automatic choke should work fine if it's connected.

[J10_IA]

Yes its 2 barrel I typed incorrectly. Sorry!

And now its off :)

[tgreese]

There is a carb heater in the manifold. It connects to a relay somewhere - you'd have to check the wiring diagrams for your year. There are also connections to the heater hoses on the intake manifold. These will warm the manifold and keep the fuel vaporized in cold weather. Both the electric carb heater and the coolant connections will improve cold weather drivability.

As I wrote above, IIRC the choke flap is entirely motivated by hot air from the choke stove. A manual choke conversion should be easy using the Help! kit from the parts store (cable, brackets, other stuff).

[J10_IA]

There is a carb heater in the manifold. It connects to a relay somewhere - you'd have to check the wiring diagrams for your year. There are also connections to the heater hoses on the intake manifold. These will warm the manifold and keep the fuel vaporized in cold weather. Both the electric carb heater and the coolant connections will improve cold weather drivability.

As I wrote above, IIRC the choke flap is entirely motivated by hot air from the choke stove. A manual choke conversion should be easy using the Help! kit from the parts store (cable, brackets, other stuff).

Yeah I have done a manual conversion a couple times, just never had one with the tamper proof "screw." I'm trying to drill it out now, awefully hard stuff, may need a better bit.

[Billygoat]

I think it is a tampr proof screw just as you typed last.
Try a pair of small vice grips to turn it.

I have never had a carb. on a vehical I did not convert, maybe the auto choke just need to be adjusted, but all the motocyles and tractors I grew up with were manual choke, so it just seems the natual way for me.

[J10_IA]

Finished the conversion.

I ended up grinding off the screw heads as it was taking far too long with a drill. I popped off the retaining plate for the black cap and there was enough of the screw left to grab with some pliers and unscrewed them.

Works well. I drove the truck around for about a half hour, also bleed the brakes. Seems like it didn't do a whole lot for the rough driving after it warms up. Perhaps helped a little bit, but it seems like it drove better with full choke. It seems to really like a rich mix. Not sure what I can do to improve the driving at +35 mph. The truck is mainly a hauler/winter truck but I would like to be able to do 55 and not take 3 minutes to get up to that speed.

Any suggestions or is that the case with this kinda truck? (first J10)

[Tornado230]

The '82 model has the BBD with the stepper motor, if it is original
The emission system for that motor is a can of worms at best.
Your best friend would be the year-specific TSM.

[tgreese]

If you do have the ECM and stepper motor on the carburetor, google "nutter bypass" for a possible fix. My quick scan of the net says that 1983 was the first year for the stepper motor, but such references are often inexact.

[jpcoutts]

I think you should start with the basics like fuel filter, float setting, accelerator pump adjustment, vacuum leaks, metering rods, etc. before getting too involved in major changes to a system that works fairly well when it's working right. Start with the simple stuff and then look at making changes when that's straightened out.

[J10_IA]

I second checked the vacuum lines and the one from the rear of the carb to the valve cover seems like the valve on the cover is not opening. The hose was actually sucked closed by the vacuum. I put a vacuum cap on both ends for now. Didn't drive any different, however, when driving with no choke (carb plate fully open) the truck would backfire and try to kill itself. If I give it full choke (closed plate) it runs fine.

I can't find any other vacuum leaks.

[J10_IA]

I will check the fuel filter tomorrow when I have light, my other truck is in the garage atm :)

Also, my carb rebuild kit comes tomorrow.

[J10_IA]

Update.

fuel filter didn't help at all. I rebuilt the carb with as much as the kit had. Which wasn't much, gaskets mostly. When I took it apart, the plunger that goes over the intake check ball was folded over on to itself. I can only guess that the last rebuild of it had gone bad. I replaced the plunger and most of the gaskets. I didn't rebuild the Venturi cover. (whatever that is)

So the differences were thus.

Coming from a stop and accelerating, the truck was performaing MUCH better. Before I if I gave it too much gas and not enough clutch, the pickup would die. Now it loved as much gas as I could give it no matter how much clutch. It had more pick up when accelerating than it has since I've owned it.

After the truck warmed up, it prefered half choke over full choke. If the choke plate opened up to full, the truck would die when coming to a stop. It also doesn't idle with no choke. Which it would before. Before If I stomped on the gas it would die, but If I slowly pushed on the gas, it would rev fine.

The float moved freely, no sticking or gunk in the carb at all. It was pretty clean.

I'm going to get my buddies timing light tomorrow and see if the timing is off.

So there is some progress but more work needed. I am trying to find where all the vacuum tubes should be going. Since the previous owner removed them all, I'm afraid that the bowl vent tube needs to be attached to make it work how it should.

[J10_IA]

Found this link, sounds like it could be contributing, I've already sprayed quite a bit of carb cleaner in it though.

http://www.jeeptech.com/engine/carter.html

[tgreese]

Found this link, sounds like it could be contributing, I've already sprayed quite a bit of carb cleaner in it though.

http://www.jeeptech.com/engine/carter.html
Basically I agree with Jim C that you should check all the factory settings and make sure everything is functioning normally, before you start looking for a more exotic cause.

The BBD's usual problem, discussed in your link, is that they won't idle. This happens most often when you come to a stop in traffic ... rmrmrmrmmm ... uh. You can drill out the idle tubes and it may make the truck idle better, but it won't affect the rough (?) driving at 35+ mph. I thought this was your main complaint.

Even though I agree with Jim, I will point out that these engines are very prone to manifold leaks at the cylinder head. Leaks on the intake side will lean out the mixture to specific cylinders, reducing power and drivability. Extra lean cylinders will also cause burnt exhaust valves. Exhaust leaks (besides being noisy) will let excess O2 in behind the exhaust valves and cause ... burnt exhaust valves. Manifold gasket replacement is a pretty common repair for these engines, in my experience.

Check your compression too. That's the easiest way to look for a leaky exhaust valve.

An engine with good compression and good oil pressure is basically healthy, so if you have those, you can look for secondary causes of the roughness.

[J10_IA]

Took apart the carb again ... cause I was bored and wanted to make sure I didn't mess something up. Cleaned out the venturi and what nots even more. Eveything looks pretty darn clean now.

Noticed the plunger was already ripped. Warranty is going to cover it and i'll have another in a couple of days.

[jeepmonkey]

double check air/fuel mixture screws. Check on jets make sure they are clean. And I think you are going in the right direction with checking the timeing. Also is you distibutor advancing like it should, that would cause poor perfomance at +35mph.