Mitsu U42T Minicab TD 1991 Inside the air filter box, there is a small damper/door, controlled by a spring, tgat appears to have a thermostat on the end of it. What is it for? And most importantly, do i need it? Thanks much.
Emission Control & Runability. Should open & close to admit warmed air from a tube and surround of the exhaust manifold or outside ambient air directly. Fred
fmartin, The spring is badly rusted. The door opens and closes, if i open and close it. I don't think it works as it should. Would it be bad if i eliminated it all together? I ask because it stays in the closed position all the time. By closed, i mean, from getting outside air. The only air it would get in this position, is the exhaust that runs to it.
Also, the tube, is from the exhaust manifold. The door is letting that air in. But is always closed to ambient air.
The intent is to draw warm air for the intake from the exhaust manifold to help warmup and cold start emissions. You should be fine to ignore it.
mr.mindless, So yourr saying it would be OK if i eliminated it all together? I mean to say, since its not opening properly, its not going to hurt anything to just remove the damper/door.
Actually you would be better to somehow lock it in the position that will allow ambient air only. Cooler air will make a bit more power and the main purpose of the warm air was to make for quicker warmups and feeding it constantly warmed air will do you no good. It may take a bit more time to warm up but hardly noticeable. Fred
Thanks Fred! The insight is much appreciated. I initially thought about doing that, but wasnt sure if it would work out or not. Since the little thing is plagued with vacuum lines and all. Thanks again!
Yeah you can lose the door... the only problem you might encounter is carb icing when the conditions are just right. Once it's fully warmed, not so much. Another option: Remove the flex hose that ducts the warm air from the exhaust system, to keep it from pulling warm air.
Awesome! Thanks Ronin. As soon as i get it back from the muffler shop, ill be removing the flex hose and locking the door in the open (ambient air) position. Many thanks to Ronin and Fred for the help.
Thats what these forums are all about. Just glad to do my little part. I'm sure Ronin feels the same as we are all in this together, trying to keep these little gems going and doing their thing. Fred
You bet Fred. The more i tinker with this thing, the more i hope to be able to give some feedback of my own and pass a bit of help on to the next guy. Its definitely a Pandoras Box. Ha! But I don't mind it one bit. Its a fun project to get the little feller back on the road. Unfortunately, Missouri doesnt have a provision for licensing and plating it, but i can drive it in the neighborhood and on the county roads. I get many a smile and wave from everyone. Joe
I am a retired American living in the Philippines and here the little midget pickups and vans are the same as the Fords & Chevvies there. Everybody has one and uses it for whatever purpose they can. Fred
Here in the Japan countryside you ain't got a chance o' gettin' your ManCard validated unless you got a kei truck. All the Old Boys be talkin'...: "hey yo... dude don't even have a kei truck... shiiiii". (Japanese equivalent.) I'm on my second in twenty years, third if you count the Daihatsu van (used it like a truck)... Prior to Suz19 I had a (89? have to remember) Mitsubishi Minicab, drove it 'till the rust in the driver's wheel well was giving me all season showers whenever it was wet. Coulda fixed that, but the engine was starting to show its age/misc. other, and Suz19 came along at a real bargain ($600). Having laid all that down in Joe's thread I shall now celebrate today's tuning success with a beer. On topic post... been thinking of eliminating all that hot air plumbing myself, and just running a K&N or the like stuck right on the carb. JDM does support... Kanpai.
Ronin, Im hoping to get all i can out of mine. They aren't scarce here, but anyone that has one isn't turnin loose of it anytime soon. At least not in my part of the country. Ill nurse this old dog as long as i can. Got some new exhaust on it today. Quiet as a mouse. I eliminated the door/flap in the air cleaner box. Found a vacuum line running to the chike that had a crack in it. Choke seems to be working fine now. But, i found another problem. This ine i believe is from pure neglect. Ill post a picture and a explanation of what i discovered.
Rgr, standing by... gonna be around all day, got Suz19 up in the air to pull the LF axle, inspect, and replace busted outer axle boot. No noise yet so I think I'll get away with it.
This is the plate on the exhaust manifold. 2 foil pipes. One of which is going to the air cleaner. I have eliminated its need by removing the little door in the air cleaner. That is the one that is broken from the plate. The other seems to run inside the body. Not sure of its purpose. Can i make a new plate and eliminate both foil pipes? And could this be part of my rough idle after warm up problem? Since its likely sucking air back into the head.
I think in your shoes I'd really lose it... wait... what I mean is, all that junk can go. Scrap the hoses, the shield, the box with the door... the whole thing. Gotta rattle like a MIL from h@ll anyhow. Run a fresh intake hose from the air filter box to the fresh air intake plumbing in the body and call it Good. Your posts have had me looking to do the same thing to S19, been running my '73 Jimny like that for 20+ years and never missed it. Been looking at the K&N-type goods too... thinking on these things. The stock air filters are actually pretty good, stock plumbing to outside air keeps cool air cool, slight disadvantage to the carb-attached filter would be picking up heat from the engine area. Hmm. Axle repair success, gonna go outside and throw it in.
Glad you got your axle squared away. I hate changing CV boots. Ill likely have to remove the exhaust manifold to remove the plate. Bolts are rusty and its a bit tight in there. It appears as though all that stuff is emitions anyway. Once I get it straightened out, ill post a few pictures of what i did and how i did it. Have a great day Ronin.
Ronin or Fred, My Mitsu has a Mikuni carb on it. On top, there is a plate with 2 (two) Phillips screws holding it down. Is there by chance a power valve under there? Thanks, Joe
Not familiar with that carb but mostly as I remember the Mikunis did not use a power valve. Maybe Ronin knows. Fred
Thanks Fred. I talked to a mechanic friend of mine and he suggested possibly the power valve was bad. Possibly accounting for the stutter after warm up. Ill go another direction. Thanks much. Joe
