First 720

[Bhagness]

I just bought an 85 720 2wd, and would like to get some advice. It has 131000 miles and a five speed. 2.4 8 spark plug motor, and I'm having issues with idle and cold performance. Low engine speed causes hesitation during early acceleration, but is fine once the revs climb. Good power in the to end, will pull to 90 no problem. I plan on getting a tune up but am also considering a weber carb swap, any advice?

[84720FourWheel]

I would say your choke isn't operating correctly. Otherwise, you may need to adjust the idle speed screw on the passenger side of the carburetor. Do the tune up, NGK spark plugs/wires. 

What is your truck idling at? Should be around 850-900 rpm. 

These trucks weigh nearly 2 tons (I think mine is right on the money @ 2T) and only have about 100 HP so they need a little bit more gas to get going. 

 

As for the Weber swap, I hear the 32/38 is the carb of choice for most. If you aren't having issues with the Hitachi, I would leave it stock. Replacing vacuum lines may clear up any carburetor issues. Take them off and replace them 1 by 1 and check for little restrictors in the old lines, they are important and must be put back in. If you screw up, http://www.nicoclub.com/archives/nissan-720-pickup-truck-vacuum-hose-diagram-repair-guide.html

 

The transmission NEEDS to have API-GL-4 that is "Yellow Metal Safe" GL-5 can have chemicals that are corrosive to yellow metals (copper/brass)

[datzenmike]

I think the 2wd is closer to 3,000 pounds

[Z-train]

Yes, it is......

[Bhagness]

Yea I checked the butterfly valve on the top of the carb and it's staying open even when warm. Other issues I'm noticing is a in frequent dieseling when turning the truck off .

[84720FourWheel]

Wow, I didn't realize the 4x4 weighed so much more. I guess with the transfer case, all the drive shafts, front differential, and cv shafts, it makes sense.

Check your anti-dieseling solenoid. The wires at the back of the carb may be loose.