LUVTruck.com

I have a '84 G200 motor in my luv. Underneath the intake manifold just under the carb there's a hose about an inch in diameter. It's about 6 inches long and connects to this plastic dumb-bell shaped plastic piece. There's also a vacuum line that goes to it. Nothing else comes out or goes into it. When I take it off there's a little gas in it, but that may be from flooding it when my carb was screwy.
It has a # on it, but been unable to look it up:

Nippondenso, CO LTD
8-94145956-0
084200-0570
M C V

I'm trying to find out what this is, if I really need it, and if I do, how to test and see if it's bad.

Thanks a bunch.

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Richard Barnes Salt Lake, Utah
1980 Luv Mikado 4X4
http://geocities.com/luvtruck2004/

Mixture control valve

It is supposed to open up and let in some air when the throttle is snapped shut quickly. The idea is that on a rapid throttle close, excess gas goes into the motor and the valve lets a burst of air in to help it burn properly instead of going out the exhaust unburnt. If you put your hand on the bottom, you should not feel any air moving normally. If it is working right, you can manually open up the throttle some (hold the motor up around 2000 RPM or so) then with your hand under the mixture valve let the throttle slap closed. You should feel some suction for a bit.

I had the one on my trooper go bad, but it was just constantly bleeding vacuum off. You could hear a pretty loud hiss coming from it. It made it impossible to adjust the idle anywhere below about 1200 RPM or it would die. I ended up capping off the big line and the smaller vac line and running without it for a while, then lucked out and found a good one for a couple bucks on ebay. Without it, the truck ran fine but tended more to backfire between shifts especially when accelerating hard. Nothing too bad, and it still actually does it some with a functioning valve, so you might just try capping things off and see what happens.

Dang, I've been trying to figure this thing out for a while. Thanks a ton, man. Ya know, it's kinfa embarrassing not knowin' all this stuff, but with you guys I think I'll know everything there is to know about my truck in no time.

_________________
Richard Barnes Salt Lake, Utah
1980 Luv Mikado 4X4
http://geocities.com/luvtruck2004/

Well I had no clue what it was on my trooper before I dug through the book to find it. If I it wasn't for the fact I had problems with it, I would still be calling it "that goofy white thing on the fender". I totally lucked out on the ebay deal, the pic on the auction actually showed the part numbers so I could tell that it was exactly what I was looking for. Finding a new replacement might be very tough, but I don't think they tend to go bad too often and should be pretty easy to find on a early 80s Isuzu of some kind.

I think I would just plug both lines going to it and see what difference it makes. Mine was leaking so badly I could hear it, but it took me a while to narrow down the leak. I ended up sticking some vacuum line in my ear and used the other end as a stethescope to pinpoint the sound. If yours is showing some fuel in it, I would think that at least it would not be leaking vac very bad. It might also be mounted too low, my trooper has it setting tad higher than the port the big line hooks to and the line is bent so there is a peak between the intake and the valve. Between the two, that seems to keep any fuel that pools in the intake from flowing over into the MCV.

Oh yeah, on getting a new one (or any factory Isuzu part) I have heard great things about St. Charles Isuzu. There is a guy named Merlin there who is a wizard (heh) at finding the right parts for older Isuzu stuff.

http://isuzu.stcharlesauto.com/frameset ... department