1986 Nissan 720 base 2wd build

[720 King Cab Killer]

Do you know where the PVC valve is on the 720? Is it right behind the motor? Like under the intake? Ik cant see it maybe I well try and feel for it....you know?  

[lugnut1009]

No clue

[Charlie69]

On 5/23/2018 at 1:00 PM, lugnut1009 said:

I know I'm a little late on this, but here is a pic of my truck when I first got it a few weeks ago from the original owner, a Baptist preacher in GA.

 

Good looking truck!

[lugnut1009]

Thanks, the picture looks better than the truck actually does, HA!  The interior needs some major work and I still have to do something about the slack in the steering and buy some tires.  But she runs great still and I occasionally drive her to work and back.

[Charlie69]

Find a good used steering box or by a rebuilt one.  Is yours power steering?

[datzenmike]

Could be the accumulated wear in all the steering ball joints and the idler arm.

[lugnut1009]

No, manual.  It probably is a little wear on every piece.  Just need to find the time to clean it all up and get a parts / price list going...

[Charlie69]

Manual makes it cheaper.

[lugnut1009]

Well I have been putting off working on my lil 720 for a while, just been busy working on other projects.  But now I'm being forced to work on it.  My primary vehicle (F250 6.0) has the inevitable blown head gasket so I'll be working on it for a while and need to make the 720 reliable.  I know I need a drive shaft carrier bearing, need to lift the front and check for slack in the steering joints and box, and now it won't idle!  So I think I need to go through all of the vacuum lines and replace them with new hose.  Does anybody have a picture or map of the vacuum line routing?  Are there any that could be removed or capped off?  Or would it be easier to try to find a weber carb and put on it?  I am on a tight budget though since my diesel is going to cost me over $2000 in parts alone...

[lugnut1009]

Well I replaced a couple questionable vacuum lines with no luck. Then I found a missing vacuum cap, still nothing. Pulled the idle solenoid and it pops open with 12v when the key is on, still no idle. So I gave up and just turned the idle up some, helps but it’s not consistent. 

[Charlie69]

I would buy a Weber and be done with the problematic feed back carb.  Does the stock air cleaner have one bolt or two on top?

[datzenmike]

First, take the idle cut solenoid out and remove the pin and spring inside and replace it in the carb. Try it, does this help?

 

Next remove the idle cut solenoid. The idle mixture screw is on the outer side of the carburetor base and is sealed at the factory with an aluminum 'plug'. Right here...

 

 

 

If you drill a small hole in the plug you can screw a wood screw in and pry the plug out. Remove the idle mix screw but count the turns so it can go back in, in the factory setting. Now get a spray can carb or brake cleaner with a red straw. Liberally spray into the idle mix and the idle cut solenoid holes using the straw. This will dislodge any obstruction. (I hope) If you spray in one hole it should come out the other. Now put the idle mix screw back in and spray the idle cut solenoid hole. This should back flush any blockage back into the fuel bowl. Put the idle cut back in and give it a try.

[lugnut1009]

1 hour ago, Charlie69 said:

I would buy a Weber and be done with the problematic feed back carb.  Does the stock air cleaner have one bolt or two on top?

1 bolt

[Charlie69]

There are a few 85 and 86 720 that had the Z24I engine which makes these the throttle body injection engines.  They easiest way to tell if it is a throttle body injection (TBI) is the air cleaner bolt or bolts.  Single bolt is carbureted and 2 bolts is TBI.

[lugnut1009]

If I get a chance this evening I will give this a try datzenmike, thank you for the advice.  Makes sense, these are just an overly complicated carb, but not totally different that what I am used to which is small engine carbs on ATV's or Motorcycles.  I wanted to remove it and take it apart but was scared all the 32 year old gaskets would crumble and I'd be in way worse shape than I am now.

 

I also plan to remove all the vacuum lines except the vacuum advance and install plugs.  I live in Mississippi so no worries about emissions, heck half of my exhaust isn't even there anymore anyway.  

[lugnut1009]

22 hours ago, datzenmike said:

First, take the idle cut solenoid out and remove the pin and spring inside and replace it in the carb. Try it, does this help?

 

Next remove the idle cut solenoid. The idle mixture screw is on the outer side of the carburetor base and is sealed at the factory with an aluminum 'plug'. Right here...

 

 

 

If you drill a small hole in the plug you can screw a wood screw in and pry the plug out. Remove the idle mix screw but count the turns so it can go back in, in the factory setting. Now get a spray can carb or brake cleaner with a red straw. Liberally spray into the idle mix and the idle cut solenoid holes using the straw. This will dislodge any obstruction. (I hope) If you spray in one hole it should come out the other. Now put the idle mix screw back in and spray the idle cut solenoid hole. This should back flush any blockage back into the fuel bowl. Put the idle cut back in and give it a try.

 

Thanks datzenmike!!! That worked great! Back idling again, must have been partially plugged for a while, idles a little high. But I don’t have to use all the pedals stopping at stop signs anymore!! Woohoo!!

[datzenmike]

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