Exciting 720

[datzenmike]

 Does the weber have an idle cut solenoid. It's job is to turn off the fuel to the idle circuit when ignition is shut off. It may not have one. In which case if a standard, hold brake down, lift clutch pedal till the engine lugs down and then turn ignition off and the added load will stall the engine. Wait till the engine is fully stopped before letting the clutch all the way up. For or five times and you will find you do this automatically and smoothly every time.

 

If an automatic just shut off in drive or reverse and it will stall from the load then place in park.

 

 

[Charlie69]

Weber DGEVs donot come stock with the fuel cut solenoid.  Pierce manifolds sells them.

[powderfinger]

If your idle is set too high it can also cause dieseling. I had this issue after fixing my AC. I had to adjust the idle up some so it would idle smooth with the AC on. I overshot the idle RPM a little and would get dieseling when shutting the truck off without the AC running.

[datzenmike]

For run on to occur you need fuel/air/heat from compression

 

 

Possible causes of dieseling

 

Idle set too high

flooding

choke not shutting off

BCDD set too sensitive not shutting off at idle

 

[jagman]

Thanks to all of you although I don't know what BCDD is unless you mean  Best Can Dumb Drivers.  It turns out that the throttle cable was slightly off and hung up causing the idle to go to 1500 RPM occasionally.  I had to loosen the cable a little. The return spring could be a little heavier as well.  Great diagnosis. I have set the normal idle at 750.   Thanks guys.

[jagman]

Well the idle climbed again so I will have to look into that.  I am curious, when I have to pull a trailer on a long incline in 5th the truck temp begins to climb.  Is it best to down shift into a lower gear for these pulls and does it prevent the near overheating?  Be well all! 

[datzenmike]

Fifth is for steady speed cruise on the highway only. Passing, hill climbing, towing or perhaps into strong wind always use forth.

 

 

 

 

[bottomwatcher]

Yep towing in 5th creates tremendous loads on the countershaft bearings which will cause failure. 4th is straight through 1 to 1 no reduction or overdrive. The rpms will sound high but the engine will be in it's best powerband for the load and moving coolant and oil pressure. Datsun engines can take high rpms all day. 

[jagman]

Yet another dumb question.  I have the tilt steering in my truck and the lever that keeps it in one setting seems to be so loose that more often than not the wheel is moving up and down as I drive.  After the last trip I put a small bungee on it to hold it up in the locked position.  Is there a spring in there that's broken? Are the parts to fix the problem available or do I have to do a rube?

Edited August 16, 2020 by jagman
add

[bottomwatcher]

Bungy =ratsun! 

[620slodat]

Somewhere here on ratsun is a fix for this loose adjustable height steering column. I've seen it, but I don't remember where. Something about removing the adjustment lever, and tightening a screw. There is a reverse thread screw some where in there, so be careful. Maybe the screw that holds the lever on.

 

Don

[wayno]

Yes it is adjustable, and 620slowdat is correct, the bolt has a reverse thread.

The photos in order, #1 the lever with the reverse thread bolt and thick washer in place, #2 with the arm loosened and reverse thread bolt/thick washer removed, you can see the teeth that make it adjustable, and #3 with the arm removed, I would have it in the tight position, then remove the arm and move it a couple teeth and then put the thick washer/reverse thread bolt back on finger tight and see if that will work for you when tightened to the stopper, then tighten the reverse threaded bolt.

Edited August 17, 2020 by wayno

[jagman]

Thank you Wayno this is just what  need to fix it without resorting to  doing something stupid (or as my son puts it "your usual work around" ).

[wayno]

It is easy to adjust to your liking, just remember that the bolt is reverse thread, clockwise loosens the bolt.

[jagman]

That means I have to forget "righty tighty - lefty loosy.

[jagman]

I have taken all your advice(s) and have made progress on using the truck as intended. Today I mounted a 2" ball on the bumper and towed the bigger trailer to pickup and deliver. I am still looking for a righteous tow bar to frame mount but the weight on the bumper is only about 100 # so I should be OK for now.   I have an exhaust leak to find and fix but that seems to be the only problem left.

I pulled the truck and trailer into Lowes to get fence posts and when I came out a Ford 2500 dual cab was parked next to it.  Another customer commented on the toy truck!

[EDM620]

2 hours ago, jagman said:

I am still looking for a righteous tow bar to frame

The D21 frame mount hitch is a contender for a direct bolt-up, not too much different on the rear section of the frames - one from a Pathy might possibly work but due to the IRS there may be more differences.

[Charlie69]

I for got to get pictures of the hitch my brother garret put on my 720.  I will try to remember and get pictures tomorrow.

[jagman]

Thanks Charlie I would also  like to know what the hitch was originally made for if you have that info.

[wayno]

Just look at any small truck tow package, wrecking yards likely have a small truck with a tow package on them, I have put several on my 720 chassis, right now I have a Volvo wagon tow hitch assembly on my 720 chassis.

[bottomwatcher]

My frame hitch on my 82 is mid 80s chevy s10. Bolted right up after drilling 2 additional holes.

[jagman]

I have been religious about staying in 4th while I have a trailer on the behind.  I am running hot this week.  The temp guage goes slowly higher the longer the drive. It doesn't seem to matter if I am towing or just driving.  Would this be a radiator or a hose problem?  How do I check to see if the water pump is properly functioning?  There are no leaks in the system that I can find.

[Charlie69]

Rev the engine and maintain a about 2500 rpm watch the bottom radiator hose to see if it sucks in (colapses) restricting the flow of coolant.  You are running a 50/50 mix distilled water and antifreeze?

Edited September 6, 2020 by Charlie69

[bottomwatcher]

Thermostat or believe it or not bad radiator caps seem to be the most common issues. Whatever you do don't buy a chinese thermostat. Good ones are up to $15 but worth it. If it continues to climb despite a good thermo the radiator is probably clogged. Look inside and see if the slotted holes look restricted. You can have a radiator shop clean it or if you are cheap like me remove it, buy a gallon of muriatic and clean it yourself. Also check the health of the radiator fins. In a humid or salt air environment the fins corrode and lose effectiveness.

[datzenmike]

15 hours ago, jagman said:

I have been religious about staying in 4th while I have a trailer on the behind.  I am running hot this week.  The temp guage goes slowly higher the longer the drive. It doesn't seem to matter if I am towing or just driving.  Would this be a radiator or a hose problem?  How do I check to see if the water pump is properly functioning?  There are no leaks in the system that I can find.

 

 

Spin the fan blades by hand. They should turn smoothly but feel like they are in thick honey. When released the blades should stop immediately. If you can get them to keep spinning at all then some of the silicon clutch fluid has probably leaked out. It's intended that at high speeds the effort to turn the blades exceeds  the resistance of the fluid coupling and there is slippage. Thus fan speeds are limited to 1,600 RPM which is more than enough for highway driving and there is some fuel savings and noise reduction. There is a bi metallic 'thermostat' that senses over warmed rad air and increases the coupling allowing the fan speed to increase to 2,100 RPMs.

 

Towing places an extra load on the cooling system and with the fan speeds limited it is possible to run hotter than intended. Every effort should be made to assure that the cooling system is operating at maximum.

 

Air delivery

Clutch fan working

Fan belt tight

Fan shroud in place

Exterior rad fins clear of bugs and debris

 

 

Coolant delivery

Thermostat working and proper range (180F)

Rad interior core free from hard water scale

Soft collapsing rad hoses.

Heater hoses NOT connected to by pass a leaking heater core.

 

Engine properly timed.

 

In a pinch roll down windows and set heater to HOT and fan to HIGH for added cooling.