I have a 98' Mitsubishi Minicab with about 36,000km. I have had it for about a year and have had to replace several parts including cv boot, water pump, thermostat, plugs, and most recently had the head decked .010 and new head gasket. Right now it is running like crap, when you shift up it just boggs down and sometimes going up a hill even in first gear it will almost stall out. I checked the timing it was good at 6 deg. BTC. Maybe fuel pump or filter or carb needs rebuilt. Is there any way to get some more power from these things? If anyone knows of any performance mods that will work such as another type of carb, maybe another ignition or coil like a msd. If someone has tried some of these things I would like to hear about them. PS I have a pull behind mower and mow about 4 acres with my mini. It always wants to overheat while mowing, so I would like to get a bigger radiator (not really bigger but go from 1 row to 2 or 3 rows). Maybe someone has used on from a small car without to much modification? Does anyone know where to get one or will I have to get a rad shop to make one? I have already switched to an 10" electric fan and that helped alot. Maybe my head was warped before I knew and that caused it to overheat. Does anyone use a pull behind with there mini? If so does it get real hot?
have you adjusted your valves (not sure if thet are adjustable on the mits) have you flushed the cooling system ? has it been bled of air...an air pocket in the cooling lines can cause either over or underheating ..again Seafoam (god it sounds like the universal fix all...but it will do wonders on dirty fuel system parts)..any other symptoms....smoking,poor idle,dieselling?
DDD, Sounds like you might have some fuel issues going on along with potentially other issues at the same time. Whats the approxiate weight on that mower? I cant imagine that it would weight all that much and the truck should pull it fine. I've done more ridiculous testing with mid-90's Mitsu's than any other trucks and they've always handled the abuse (pushing and pulling heavy loads). How dirty is the engine/undercarriage on your truck or how dirty was it when you got it? It seems that I can directly relate this to what I can expect when we get the trucks in. If not already done, replace the fuel filter (driver's side under bed - midway down inside frame rail). It's also probable that your carb needs to be cleaned. Get some SeaFoam and run it through the engine in volume. I've found that getting a squirter (like a turkey baster) and shooting directly into the carb while applying throttle to the running engine is the best method. Some have actually dropped the fuel line directly into the bottle. If you've never used it before, you're going to fog-out the area with white smoke until it burns off. These two quick fixes will help decide if you have a simple fuel delivery issue, or if you need to take it to the next level. Also check your coolant system for air pockets - bleed it. Many owners have had issues with overheating and/or engine power decrease due to air bubbles. This will get you started and wont cost much. I've occasionally gotten a truck through that ran rough or had diminished throttle response which was cured through simple methods. - Dan
I plan to change the fuel filter tommorow. I did run some seafoam in the gas but if filter does not fix it I'll try shooting it directly into the carb. I really don't want to have to tear the carb off, there are so many vac lines and its kind of hard to get to. Quick question is that the fuel pump in front of the filter? It's about the same size as the filter itself.
i dont think u need a bigger radiator i use my mini for four wheeling in the hills and it never tryes to heat cheak for air and make sure the cooling fins are clean just a thought
As for the overheating issue I think it may have been due to the warped head. When I bought the truck it had a bad water pump and I may have warped the head before I had it repaired. I took it to a mechanic down the road to have the water pump put on while I went on vacation and he said the head gasket was fine but I think he just didn't want to mess with it. $200 in labor seemed a bit high for a backwoods mechanic to change the water pump. I wish I would have done it myself, Live and Learn. I will wait untill mowing season and see how it does with the newly decked head before I worry about the overheating. It may be fixed. By the way I would guess the mower weight to be 300-400#. My rhino never had a problem with it so I would think the mini should handle it. Thanks for the input I will let you know how things turn out.
Some times these trucks can be a pain to bleed the air out of system. You should have a bleed screw on top of the thermostat housing. The bogging sounds like carb. I recently had a suz. that would fall on its face when given fuel. It would start up fine and idle fine. I did everything to it that could be done to solve problem. I bit the bullet and took plenty of pictures of carb. and pulled it, threw a rebuild kit on and varoooom. Best running truck Ive had.
I changed the fuel filter today and it didn't help so I was going to pull the carb. I got all the vac lines off, the fuel returns, and pulled the fuel line only to find it was bone dry. So I thought before I tear the carb the rest of the way off I would turn the key on to see if fuel would flow and it didn't. The mitsubishi does have an electric fuel pump doesn't it? I'm assuming it is the little canister looking thing in front of the fuel filter because its the only thing with wires going into it between the tank and the carb. Or is it actually in the tank. Assuming it is in front of the filter I checked the wires with the key on two of them are 12v+ and with the key off none of them are. With the key on I plugged the harness back in and it made no sounds. My mini has always been hard to start and lately it is even worse, could be because it has to build a siphon. Can someone please confirm that is the fuel pump and that it does sound like the problem. If so has any one replaced it with a universal fuel pump from napa, advanced auto, or auto zone. If so do you know a part number or how many PSI to look for.
yeah, the pump is near the filter and it can be replaced with any low psi universal pump from any of the parts houses. the psi is not extremely critical but, should be in the mid range of single digits to avoid hammering the needle and seat in the float bowl. If i remember correctly, the fuel pump only moves fuel while its cranking or running. not with just the key in the on position. might want to confirm that before investing time and dollars in the pump. I cant remember the part#'s but have bought pumps from napa and lawnmower shops that range from 10.00 to 40.00 depending on how rushed i was to make the repair and not shop around. Is it just hard to start from a cold start? I've had gummed up check-balls inthe carb that would let the bowl siphon out if it sat for a while.
I was thinking about somthing like Napa #AFP E8135 which has 5.5-9 PSI and 1/4" inlet and outlet. I will check the cranking or running thing but I do know the pump is getting power when I turn on the key. Thanks for the input I'll let you know how it turns out.
not the pump I did end up changing the fuel pump, but that was not the problem. So I ended up tearing the carb off and took it completly apart. Aside from the coolant lines ,which were completly clogged, it was very clean inside and nothing looked like it needed replaced so I put it all back together. Now my truck has a very fast idle and none of the ajustments seem to slow it down. It is also going thru alot of fuel although it does not smell rich. Fast idle could be vac leak maybe? I know I attached all the lines back to the carb. Any suggestions on which ones could cause this if it were leaking. Also truck still lacks power when second gear or higher is used, but runs fine in first. Is there maybe a sensor that could be bad or a valve of some sort that I am overlooking? How about valve adjustment? Can the valves be adjusted on the mitsus? I did just have the head decked and the machinist tore the whole head apart to check for cracks and clean it all up. Could it be that he over or under tightened the valves? I have never messed with the internals of auto engines that much, so if someone could explain how to adjust the valves than I'll try it. I would love to be able to take this thing to someone who could tune it up and get it running good, but the mechanics around here act like you have a nuclear sub or something. Everyone on here has been very helpful and I appreciate there patience with me and my mini.
Found something on here about air in coolant system I will try to bleed it tommorow. It may have air in there since I tore apart the carb and blew out the lines. If nothing else maybe that will help the fast idle.
No good Bled the air out and plugged a vac leak that has been there since I got the truck. Started it up, let it warm up and I was able to get it to idle at what sounded about right. Took it down the road and came to a stop idle was high again and truck still has no power in 2nd gear or higher. Any input on valves?
Ready to give up I got to tell you I'm ready to consider getting rid of my mini. Would trade for a nice rhino or similar. I sold my 06 rhino to buy my mini, I had it for 3 years never had to do anything to it but change the oil. I work on my mini non-stop. I love the cab and it's quiet, it hauls a lot more but it is very frustrating. Is there a mini truck mechanic within an hour of Wheeling WV.
Have you checked your distributor ? Does it have a vaccum advance on it and is it working? Also it may have a mechanical advance inside that may be froze up! If the timing isnt advancing it will run poorly, I know from my recent experience with my honda I had a similar issue and found the vac advance worked but the advance plate was froze up, I disassembled the distributor got the plate freed up so the vac advance would work what a difference it made in the performance, also if your distributor isnt working properly that can cause a heating problem. This may help, I hope!
Yesterday I had the same thought and I was thinking about tearing the vacuum advance off and making sure it is working properly later today. I didn't know there was an advance plate inside, but I will also check that out. Thanks for the input and at this point if someone told me to check the blinker fluid I'd probably be out there looking for a dipstick.
blinker fluid should feel dry to the touch and smell like uncooked chicken weiners ...torque the fluid to 300# and good to go All kidding aside,hope you get yer mini running soon..I'm sure it's frustrating..hang in there
OK I think I'm back to the carb again. After adjusting my valves, changing the fuel pump, new plugs, checked for vacuum leaks, checked timing, and tore apart carb and cleaned it. Then today went to start it and it would not fire, it was flooded. Took off air intake and gas was running out of the carb so something must be sticking in there. Even though it all looked good inside it must need a rebuild kit. Anyone know where to get a carb kit or a rebuilt carb for a 98' mitsu?
