I have a 1985 Z24 backed with an Automatic transmission Fleet Owned 720.
I had just replaced all 8 spark plugs, wires, both ignition coils, cap and rotor. She was running like a dream..when the next day she was stolen almost imedietly after I had started her, so she could warm up, seeing as how it was -35°F outside that day.
After getting my truck back, it wouldn't stay running smooth once the engine became hot. (Standard running temputure) first start of the day, everything would be fine, until it gets to running temputure, then it develops an intermittent random sputter, almost akin to a Misfire.
If I shut the engine off while at running temp, it will not restart easily.
The engine will crank, but it acts like it is flooded and can't breath. After a few seconds I stop, wait a few minutes, and try again. It will come to life after sounding like a .38 cal was fired-
(cops have shown up at my house multiple times since my truck was stolen, "responding to gunshots" and I'm like "you guys have my gun in your evidence locker, the sound reported was my truck")
-it will run with coaxing (holding the pedal down 1-200 RPM higher than flat idle) at stop lights it will cut out upon acceloration almost as if it is not getting enough Air.
Now, mind you, this is only while the engine is hot, or warm.
Dead cold, (several hours of sitting dormant) it starts right up and runs like a dream, until it gets hot.
I decided with help from the Nissan 720 Shop Manual the first step was to check the Carb.
I saw that the plug was still covering the mixture screw, so I decided to check the rest of it. I found the accelerator cable was stretched 4cm. I found an armature sheered off, and the diaphragm in the Auto Choke was shot.
I decided that the best thing to do at this point would be to purchase a new one, being the broke ass northern'er I am, I bought the Ching Brand off FleeBay.
seeing as how the truck is a proud member of the Quarter Milion Mike Club, by having 350,000 miles on it, I was not going to be assed into buying a 3-400$ Weber.
So, new unit came in, and I noticed several small differences between the Hitachi and the Ching.
The Ching has No emissions system parts, like fuel air ratio sensor, a few vacuum lines and a breather line.
So I installed plugs on the other vacuum units in the truck that connected to the carb, and then fired her up.
After 20 second I smelled a Lot of gasoline, and the truck started acting bogged. I immediately killed it, jumped out and inspected the engine, gasoline everywhere from the top of the carb.
The float was stuck open allowing the fuel pump to continue filling the bowl.
I removed the new carb, brought it back home adjusted the float and now I'm wondering if anyone else has used the OM Replacement style carb.
I'm also wondering if my trucks electrical system is confused since the Hitachi has several wires in its harness going to different seonsors, but the Ching only has 2 wires, one being red, going to the anti deiseling solinoide, the other being Blue and going to the auto-choke.
Also, I'm wondering if anyone out there has any Hitachi parts laying around, mainly the cover for the float.
Ching brand comes with a Flat Float Cover, without the window. My Original Carb, also, was missing the window, as if someone had already once worked on it previously and replaced the cover.
1985
Z24 720
Automatic
Regular Bed
Standard Cab
Bucket Seats
350,000 mi.