Hello everyone. I have posted a couple of these pictures on here a few months ago but didnt seem to get much of a response so I thought i would try again and see if someone can help me out. I'm having trouble with my 95 mits starting when warm. Starts fine cold. I am hoping it has something to do with this carb. After buying the service manual and trying to adjust the carb I am wondering if someone can tell me just what the gold colored screw is in the middle of the picture and on top of the carb? I am assuming is has to do with the amount of fuel or air being let in as the further I screw it in the less rpm's get. However in the manual and in searching the many carb threads I can't seem to find any info as to where it should be set, etc. The only info I find has to do with adjusting the two screws in the other picture. Them being the chocke adjustment and fast idle. Of which I have the fast idle screwed all the way in and it barely adjusts the idle so not sure if i have other issues with that too or not? Any info would be greatly appreciated. Thanks
I briefly messed with the carb settings over lunch hour and think I figured out that gold screw determines how much fuel is being let in because i screwed in/closed it and rpm's went down. I let it run for 15 minutes and did not have all the black smoot that I usually have when it sits and idles. I then shut it off and it fired right back up with no problems. The only other question i now have is the choke screw and the fast idle screw seem to do the same thing on this carb. For example both screws seem to adjust the same lever?? is something not put together right or something? I know a while back the fast idle adjustment lever nut fell off and maybe it didn't get put back on right? because right now my choke screw isn't even touching the lever and the fast idle is barely touching its lever. Heck if I know.
try this link to carb exploded diagrams for your truck...sorry i don't know the settings for your carb.. http://mitsubishi.epcdata.ru/minicab/u42t/hfdv/fuel/carburetor/
Thanks Fupabox. That explains the gold screw as the carb mixture setting. Kinda what I had figured and good assurance. Thing is, the english manual I have nor anything I've found on the forum suggests the setting for that screw. It mentions the choke and fast idle but cant seem to find info on the adjustment of this one. Pretty straight forward but just surprised there isn't somekind of starting point suggested. Seems to be running better now. However last night it would idle great and then when I would go to put in gear it would rev up rpm real high for about 5 seconds then let off. Only when I would put in gear though. Almost acts like some kind of vacuum or something as i can feel the gas pedal get pushed in even when i'm not pushing it in. I can live with it but it sure revs up pretty high. Thanks again
vacuum leaks are 85% of carb and idling problems, use a vacuum gauge or carb cleaner, carb cleaner will send the engine to high idle if you have a vacuum leak, make sure the vacuum port in the air cleaner canister is working properly, also check that your vacuum advance hose isn’t cracked coming off the distributor to the vacuum manifold tree. The vacuum manifold tree is brass on the bottom to go in to the block and plastic on top. Plastic wears out with time and will break or leak, which causes a vacuum leak. Some manifold vacuum trees are 3 or 4 port, make sure to replace it with a new one. When I buy parts I buy 3 at a time that way I have them on hand or in case they can’t get them any more. The vacuum manifold tree is located behind the carb. If you looking at the carb from the right side of the bed, it will be to your 1 O’clock tucked down inside. Remember to use a marker or different colored tape to mark the vacuum lines so you know where everything goes back too! Good luck!’
