Friends, please help me as I try one last time to dial in my idle, carb, and timing situation. I followed the procedure below as best I could. I am not clear on a couple of steps, with questions in red below:
POST FROM THE FAQ "UPDATED CARB TECH":
This was added to the FAQ already, just thought I would post results and the one modification to the method I made.
I Adjusted the carb per Treeroot's and IDave's recoomendations and it runs great warm, starts up fine at cold with a little choke and runs fine then as well. This method was easy and the only thing I did different was used a sponge over the carb instead of putting the filter back on. I couldn't get to the mixture screw easily. My idle now is set at about 650-700 rpm.
Again, credit goes to Treeroot and IDave and I have pasted their instructions below:
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.
I checked for vacuum leaks twice with this method. It just died, no increase in idle speed.
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.
I tried to decrease the idle using the idle speed screw but could only get it to increase by turning it clockwise-I couldn't get it to decrease until it was barely chugging.
Make sure the choke is open completely.
I did this, it was.
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. It was installed.
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 )
Yes, I did this at the brake booster hose.
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
I tried to get the vacuum level to change by following this, starting with the fuel mixture screw two turns counterclockwise (out) from the bottom. I backed it out 8, 10 turns with no change in the vacuum reading (or RPMS) at all. Vacuum read 18 inches steady.
Set idle back to spec.
Should this be tried with the vacuum gauge still attached? As mentioned above, the idle speed screw adjustment was not doing much-not sure why. Yes, I used the idle speed screw buried beneath the linkage on the firewall side of the carb base.
Check timing.
With the vacuum line removed and connection plugged? And vacuum gauge removed from the brake booster line at this time?
Go through carb adjustments one more time.
I wish I could, but couldn't quite get there.
Set idle
Idle speed screw not working, at least in the counterclockwise direction...
Grab a beer and let the truck cool down.
I may start drinking again soon if I don't figure this out; maybe I should just take it to the shop?!
Thanks to all for your help with this!
Dave
POST FROM THE FAQ "UPDATED CARB TECH":
This was added to the FAQ already, just thought I would post results and the one modification to the method I made.
I Adjusted the carb per Treeroot's and IDave's recoomendations and it runs great warm, starts up fine at cold with a little choke and runs fine then as well. This method was easy and the only thing I did different was used a sponge over the carb instead of putting the filter back on. I couldn't get to the mixture screw easily. My idle now is set at about 650-700 rpm.
Again, credit goes to Treeroot and IDave and I have pasted their instructions below:
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.
I checked for vacuum leaks twice with this method. It just died, no increase in idle speed.
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.
I tried to decrease the idle using the idle speed screw but could only get it to increase by turning it clockwise-I couldn't get it to decrease until it was barely chugging.
Make sure the choke is open completely.
I did this, it was.
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. It was installed.
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 )
Yes, I did this at the brake booster hose.
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
I tried to get the vacuum level to change by following this, starting with the fuel mixture screw two turns counterclockwise (out) from the bottom. I backed it out 8, 10 turns with no change in the vacuum reading (or RPMS) at all. Vacuum read 18 inches steady.
Set idle back to spec.
Should this be tried with the vacuum gauge still attached? As mentioned above, the idle speed screw adjustment was not doing much-not sure why. Yes, I used the idle speed screw buried beneath the linkage on the firewall side of the carb base.
Check timing.
With the vacuum line removed and connection plugged? And vacuum gauge removed from the brake booster line at this time?
Go through carb adjustments one more time.
I wish I could, but couldn't quite get there.
Set idle
Idle speed screw not working, at least in the counterclockwise direction...
Grab a beer and let the truck cool down.
I may start drinking again soon if I don't figure this out; maybe I should just take it to the shop?!
Thanks to all for your help with this!
Dave
