Carb question 83 720?

[danfiveten]

Well i finally got around to registering on here, browsed the forums alot, but never really had a question untill now. I just got a 83 720 in trade for a laptop, has 104,000 original miles, needs shocks baddly, but my biggest problem is with the carb. The motor is very very strong, i get the wheels to spin on her, but the idle sticks way to high, ive adjusted the idle but it dies when i have it to low, and at any setting after i drive it for a few minutes when i stop it wants to die unless i keep giving it gas. Its got a (Quality reman carb) quality my ass replacement. Any ideas that could cheaply work for now untill i do a newer carb setup, maybe a webber? I just got this truck because it was a great deal, and i need a truck, i also miss my old 720, and i already find myself looking at what i can do to fix it up lol, i just want to have it run better for now, has no issues while moving, just stopping :(. any help guys.

[datzenmike]

Take the air filter off and look at the carb. Is the choke plate closed or almost closed like this when the engine is warmed up?

 

http://i138.photobucket.com/albums/q251/datzenmike/720%20stuff/carb720notlikethisLarge.jpg[/img]"]

 

It should be fully open and like this:

 

http://i138.photobucket.com/albums/q251/datzenmike/720%20stuff/carb720shouldlooklikethisLarge.jpg[/img]"]

[danfiveten]

Its open. Its a new reman carb from a different company, ive heard bad things about some of the reman carbs.

[datzenmike]

Then check that the secondery barrel is fully closed. Try pulling down on the vacuum diaphragm that opperates it. It may be stuck slightly open. I had this on my Z engine for months, tried everything to get the idle below 1,800. One day I was fooling with the secondery and it clicked shut and it stalled. I reset the idle speed and I'm good to go now.

 

Also check that if the throttle cable is set too tight and not allowing it to return fully to idle position. Just take the cable off and start, if it idles fine then the cable is the cause.

 

If you know where the fast idle cam and linkage is see if the set screw is on one of the steps causing a fast idle. It shouldn't be as only the choke on should cause this. Bent or dirty sticking linkage can also cause this. I'll post a picture odf what to look for to-night.

[danfiveten]

^ Thanks man i appreciate it. The idle was stickin at 2k today, but she didnt die once, first time driving it to and from work i had no issues other than the idle to high. Kind of nice to have a daily driver so i dont rack up the miles on my altima durring the winter.

[datzenmike]

This is the fast idle cam:

 

http://i138.photobucket.com/albums/q251/datzenmike/720%20stuff/carbZ24fastidleadjustLg.jpg[/img]"]

 

It's just above where the throttle cable connects to the carb. The plastic cam has steps on it that the set screw sits against to prevent the throttle from closing and gives a higher idle speed. When the choke is fully open as in the second picture previously, this cam should drop down out of the way by it's own weight. If the linkage is sticky the cam may stay in the on position. Spray with carb cleaner and work back and forth to loosen it up. Once the cam drops down the throttle can now close properly to the idle position.