OK you carb experts (1 Viewer)

[Romer]

I am trying to set my fuel mixture. So, I used the FSM and started at 1.5 turns. With the engine running (it was warmed up) I turned it to 3 turns out until it did not speed up any more.

Started this morning and kept dieing, gave it some choke and let it warm up and it worked OK. Died at a stop sign. When it was fully warmed up, it would work fine.

So, now I am adjusting it cold and I am about 5-6 turns out. I have to let it cool down to make sure its OK. I know it needs to warm up a bit and its normal to give it choke. I am trying to find that proper balance (Isn't everybody?) and keeping the RPM at about 800 w/o choke.

Is 5-6 turns out on the fuel mixture screw normal? Where do you guys have your mixture set. I am at 5300 ft.

Second question. While idling in the garage, I noticed the barrel closest to the engine is wet (from fuel) and the barrel closest to the brake master is dry. Does this second barrel only kick in when you are driving and need the extra fuel? I'll go look at it some more to make sure after it cools down again.

 

[hammerhead]

My mini acted like that when I got it and the problem was the fuel cut-off solenoid. Make sure it has power and is functioning properly...

 

[Romer]

Did it run fine when you increased the mixture. Right now at 5-6 turns out, it seems to be fine. Maybe the diff is the altitude and the cold.

Or were you refering to the 1 barrel dry?

 

[Pighead]

Not an expert, but I've been fiddling with this Pigcarb for 17 years now...
5 or 6 turns out on the idle mixture screw does not sound like too much.
Sounds about right. I spent a long time trying to get mine to run too lean, backed it out and it ran better.
That second barrel, the dry one on your carb, that's the secondary. Only gets wet when you open 'er up.

 

[treerootCO]

Vacuum leaks need to be fixed first. Pull the air cleaner and with the engine running, block off all airflow to the carb. Don't use your hand because it could backfire out the carb. I use a piece of cardboard that is big enough it won't get sucked in. As the engine dies, listen to the idle. If it goes up before it dies, you have a vacuum leak/leaks. If it just dies, proceed to carb adjustments.

If you have a vacuum leak/leaks, best way I know to find them is with water. Carb cleaner/Ether works but burning down you, your house, or your truck isn't fun. Just buy a cheap 1.00 spray bottle. Engine is running and warm so I highly doubt a cracked block is even possible. Mist around the engine on all the hoses and fittings. Anywhere you spray and the engine rpms drop, you have a vacuum leak. Somewhat messy but this is another one of WD-40's many uses as well.

The idle mixture screw is only for idle. If you look at a carb out of the truck, you can see a small hole below the throttle plate. It is very important you have the idle low enough that the engine is running off that hole. There is another above this one and as you increase your idle, you expose the second hole.

Your engine needs to be at operating temp.

Set your idle down all the way. Most Cruisers will allow you to lower it until the engine dies. Turn it up around 450-500 so the engine is slow but running by itself.

Make sure the choke is open completely.

Air cleaner needs to be installed. Even though it makes it harder to adjust, you need it on because it changes the air/fuel ratio.

Hook up a vacuum gage to direct vacuum. Your brake booster hose will work. (be careful not to break the plastic taking it off. Been there )

Adjust for highest vacuum at idle. 15+ inches of mercury at your altitude.
There is a plateau for max vacuum as you open up the idle mixture, and once there, I would then adjust down (tighten) to the point where the vacuum begins to fall. There is some delay in response after an adjustment, so beware. - IDave

Set idle back to spec.

Check timing.

Go through carb adjustments one more time.

Set idle

Grab a beer and let the truck cool down.

Adjust choke cold or if manual, pull until truck runs and go buy more beer. Make sure on both that the choke closed doen't completely block off air to the engine. The stops usually keep it slightly open even when fully closed or choked.

The only reason for a choke is to increase fuel until the intake manifold can warm up. At colder temps, fuel doesn't atomize. Instead it tends to condense on the sides of the intake. Once your truck warms up, this is no longer an issue. Assuming everything else is ok, it should run fine. Keep in mind how well and efficient a Cruiser's intake is designed.......2" vs. 8" to the 1 and 6 cyl doesn't help in the cold.

 

[Landpimp]

and it won't open up parked in the driveway, needs to be under load, seems like 40mph+ and mashing your foot............should kinda feel it kick in.

That second barrel, the dry one on your carb, that's the secondary. Only gets wet when you open 'er up.

 

[Romer]

Wow Mike, Thats a lot of info. Thanks!

I'll go check for a vacuum leak, but it died because I set it to lean. Was running fine, but I went through a set of plugs faster than I thought I should even though they looked like the were wearing normal. In the winter with the top and doors (both soft) I get that exahaust smell. It's not gas and I have had the exahaust system checked for leaks. Thought maybe the fuel mixture might be rich. I was told it was rich when I got my emissions 18 months ago. It had this same smell before I took the hardtop off last year.

Just decided to go and adjust the mixture to the right level. It ran great last week, sat for 5 days and had the issues I stated until it warmed up.

I have done the vacuum check with timing and just rechecked the timing last week. Still set were I put it. My vacuum is about 18-19 and I think thats great for this altitude.

The FSM says to set the idle to about 690 rpm.

Again, what I am working is the smell. Even lean today, it was still there. I am attacking the carb because I read other posts that said the same smell went away after a Jim C rebuild. I have used the BGK44 spray on carb cleaner and the same brand for in the gas tank.

To summarize:
I think that the 5-6 turns out is OK. My question on the second barrel was answered. I'll check for a vacuum leak. Any more ideas on the smell issue, or am I left with a rebuild. I don't want to spend $300 on a rebuild if it's running OK.

Does Orion make a carb?

Ken

 

[desertdude]

Great write up TreeRootCo. should be in the FAQ's

 

[Romer]

Real time troubleshooting. Went out and started it up cold. Needed a little choke, but I think I have that right balance. Let it warm up until I didn't need the choke and then covered the carb. It did not speed up, slowed down and died. Did this twice to make sure.

So, according to your write-up, no vacuum leak!

 

[IDave]

I, too, live at about that elevation (5200 ft), and I totally buy into Mike Treeroot's method. With the exception that I would say there is a plateau for max vacuum as you open up the idle mixture, and once there, I would then adjust down (tighten) to the point where the vacuum begins to fall. There is some delay in response after an adjustment, so beware. Also, I have the high altitude jets in my carb, which make for a leaner condition to start. I end up at more like 4 1/2 turns out.

I have not been able to achieve more than 16.5 inches of mercury since getting myself a vacuum gauge that is accurate, and I think that that is in line with what Mike is saying.

 

[treerootCO]

thanks. I agree with the plateau as well. I have seen it level out and it takes multiple turns before vacuum drops again. Take it the highest vacuum, turn it back in until vacuum drops and then back out slightly.

My truck stinks worse than yours Romer.

Exhaust needs a slight downturn and exit behind the rear wheel to the side. I have been experimenting with the stink and this setup works the best. Worst is having the end of the pipe under the truck, 2nd worst is straight out the back, and 3rd is in front of the rear tire on the side. Not sure why but the slight downturn is like magic. Lots of smoke and the mirrors help too.

 

[Pighead]

If your pulling 18 or 19 inches vacuum, you don't have a leak.
Naturally your running rich, what did you say your altitude is?
Your not going to be able to correct for that with the idle mixture screw.
I'm thinking you need to re-jet...

 

[Romer]

My truck stinks worse than yours Romer.

Exhaust needs a slight downturn and exit behind the rear wheel to the side. I have been experimenting with the stink and this setup works the best. Worst is having the end of the pipe under the truck, 2nd worst is straight out the back, and 3rd is in front of the rear tire on the side. Not sure why but the slight downturn is like magic. Lots of smoke and the mirrors help too.

Mine comes straight out the back and points down. So, you think I need to move it so it goes out the side behind the pass wheel?

BTW

 

[treerootCO]

You can experiment driving mine. I have the flexy pipe on there now. Not sure if reworking the exhaust is worth it. Most LHD exit left. Just because your eyes don't burn doesn't make it ok to gas the passengers.

 

[nuclearlemon]

You can experiment driving mine. I have the flexy pipe on there now. Not sure if reworking the exhaust is worth it. Most LHD exit left. Just because your eyes don't burn doesn't make it ok to gas the passengers.

why not?

 

[dd113]

Cool write up. This is exactly what I do but never had the thought to write it up. One thing, timing will work against or for this. Adj timing using a vac gauge to get it as hi as possible then futz with the carb. it usually takes a number of test drives to get it exactly right.

 

[JohnL]

Awesome writeup...a link in the Tech section?

 

[IDave]

Adj timing using a vac gauge to get it as hi as possible then futz with the carb. it usually takes a number of test drives to get it exactly right.

I always do the timing and idle mixture together when I have the vacuum gauge on. But I find that if I set the timing at max vacuum, I will get pinging under load, so I have to pull it back the equivalent of an inch or so of mercury (which irritates me no end, because I want it all ). Is that just my rig, or do others see this?

 

[Pighead]

I always do the timing and idle mixture together when I have the vacuum gauge on. But I find that if I set the timing at max vacuum, I will get pinging under load, so I have to pull it back the equivalent of an inch or so of mercury (which irritates me no end, because I want it all ). Is that just my rig, or do others see this?

Not just your rig.
That is just how I set my timing: Max vac, 'tard it just an inch or two..

 

[dd113]

I think almost all motors will do this but I set it to max then test drive it then back it down a touch.