When I bought my 1992 Acty 3 yrs ago, it ran great. A year later, the original muffler rusted out so I bought a "good used" one from some guy in Yorkton, SK. It had only one hose barb coming out of it whereas the original had two. The original had a hose running from the muffler going to somewhere in one of the the rear frame members and another hose that went to the airbox. The used replacement had only the provision for the hose going to the airbox. This used muffler was completely shot within a year and the engine performance level seemed to drop off during that time. I adapted a different muffler to it last summer while still keeping the portion with the hose that went over to the airbox. Things seemed ok for awhile, but I soon started noticing the performance wasn't there and the air filter would clog up prematurely.......also the gas mileage was getting really bad. So a month ago, I blocked off the hose that went to the airbox and plugged the inlet on the airbox and installed a new air filter. WOW, what a difference! The little truck has more power than it ever had since I bought it and it's fuel mileage has really improved.............I think I'm getting 48+ mpg at 90 km/hr. And my air filter is nice and clean after 2300 km of use. I have no idea what that hose was there for? Whether it had something to do with emissions or if it is related to cold weather starting, I don't have a clue. All I know is the truck is running fantastic now.........I can pull 100 KM/hr anytime I want, even going into a decent headwind. I'll have to wait until winter to see if blocking off that hose has any adverse effects on cold weather starting or cold weather running, but I doubt it'll have any bad effects. Has anybody else eliminated this hose? Do the other makes of mini trucks have such a hose?
the hijet has a warm air intake that needs to be blocked off for use in the summer (vacuum flap)...might be tough to start in the winter but you never know till you try
Sorry I don't have any pics handy at this time but I'll try to snap a couple the next time I have the truck in my shop. There's really not much to look at as I simply blocked off the hose that ran from the muffler to the airbox using some sort of plugs (I can't remember exactly what I used for plugs). Winter has set in here now with some pretty cold temps and the truck seems to be starting and running every bit as good as it did other winters when I had the hose hooked up.....so it doesn't seem like it's affecting the truck's cold weather starting. However, I have had another problem pop up in the last few months which I really haven't figured out yet. And it's one of those intermittent things that's difficult to diagnose. Once in awhile, the truck will refuse to start. This happens only if I've been driving the truck and then shut it off and attempted to restart it within 5-20 minutes after having shut it off. It cranks over perfectly but absolutely will not start at such times. It doesn't occur every time I use it under those conditions......only when you really need it to start (like when you are in the middle of nowhere with no cell phone service). I have yet to figure out if it is spark or fuel related because I've never had the required wrenches with me during those episodes in order to remove the engine cover and the spark plugs. My best guess is that it is likely vapour lock because the problem has not recurred since the colder winter weather has set in. Though this problem has developed since I blocked off the muffler to airbox hose, I really doubt that had anything to do with it. Anybody else ever experienced this sort of problem?
Get a can of starting fluid and keep it in the truck. The next time it does the no start thing hit it with starting fluid and see if it starts up. If it starts up with start fluid you most likely have a fuel delivery problem. If it doesnt start its most likely a electrical ignition (no spark, possible coil) condition. If you have someone with you you can pull a plug leave it in the boot and ground it out and have the other person crank it while watching for spark. If no spark its something electrical. So theres two thing that will help you figure it out.
I have a 1997 Honda Acty HA3 Japan version with 660cc. Had a similar problem, but the car did not get on full speed. Problem: high fuel consumption, worked only up to half throttle, with WOT black unburned fuel was coming out of the exhaust and RPM went down. Removed the intake airfilter, without airfilter it ran good = more air. So I bought a new airfilter, installed it, same trouble. Check spark plugs, ignition wires, distributor and rotor, fuel pressure regulator, all fine, spark plugs were black from unburnt fuel. Then I asked a friend who knows these engines very well and he showed me the repair of the carb as shown here http://blogs.yahoo.co.jp/kurumanosentakuya/51811442.html Actually we did not have to disassemble the complete carb, but he told me to order 2 parts which are usually the problem. attached to the carburetor 16024-PZ3-000 solenoid for air 16031-PZ3-000 solenoid for air 16024 solenoid was dead and did not move, now full power again. He told me:'I know that, The air vent cut-solenoid. The air vent cut-solenoid function is return to inlet and suction side for vaporization of fuel from fuel-tank. Then, mix it with fresh-air and filling for cylinder. If doesn’t work for these parts, not enough air for air fuel ratio. So accordingly too rich-condition. These similar problems are many occurrence to HONDA-Acty.' this was was not working http://www.youtube.com/watch?v=2zblyxQzyf4 this is a link from internet, in my case the solenoid did not move at all. At full throttle black smoke came out of exhaust =unburned fuel. Checked spark plugs, distributor, ignition wires. Removed air filter in air intake, full power. So replaced the airfilter, same trouble.
