I purchased a 95 mitsu minitruck about 2 months ago. The past two weeks I've noticed it acts like its lagging in power. Feels like it wants to go but just cant do it. Starts and idles awesome but just feels like something is holding it back?? What could it be? Im a newbie and is my first truck. I don't really know what to expect from these minis. I have 23 in mud tires and the fastest i can get it to go is about 75km. Is this normal? What might be holding it back? Has new plugs, fuel filter, distrib cap. Please help as I need this thing in top shape for hunting season!! Thank you!
I did. Thanks. Brand new filter. I took the cover off, etc to check it and I assume I got the cover back on just fine. However it was after I did some simple check overs that this prob occured. Checked filter, and few other simple things. What could have I screwed up?? this truck ran great and compression was checked out and is good, etc. something????? what could it be???
what fuel filter did you use? was it a stock replacement or a universal? could be restricting fuel flow..though you would think it would sputter at higher speeds...could have knocked the timing out of whack when the cap was changed...air filter may be restricting as well ..also possible to knock a vacuum hose off while working near the carb...
Thanks fupabox. It was a stock fuel filter and the cap was changed by a dealer that I purchased it from and it has run great for 2 months. I'll have to look it over tonight and see if I can see anything. I can't imagine i knocked a vacuum hose off but never know. Another guy in town has the same mini as me with the stock wheels and he can run 60mph and my top speed is 45mph (when it was running good). Is this normal with my bigger mudd tires?
Keep in mind changing the tire size will effect the speedo. With larger wheels and tires the speedo will register a little slower than you are actually going.
The tires and wheels have been on it the whole time. Good call tho. It kinda hard to explain but it just feels like at higher rpm it kinda flatens out and feels like a brake holdin it back or something. Today I started it and reved it up a few times and noticed on my concrete a black mark from stuff coming out of the exhaust pipe. Could something be wrong with the cad coverter or something??? I'm clueless because it revs up just fine without anything holding it back but the top half of the rpm when driving its like it just winds up but no power. No need for a 5th gear at this point. need help!!
Clutch slipping? Put the truck in 1st gear with Emer. Brake on let out the clutch easy and see what it does. If it wants to move its more likely ok, if its not really trying to move clutch is wore down. Or get it into 4th / 5th gear with some speed and step on the fuel and if engine revs up but speed stays some what the same that would be another indication of clutch slipping.
I kinda wondered that myself but it sure dont seem like the clutch. What about bad gas? Running 10% ethanol a bad idea? I've ran a tank of it thru before and ran fine so not sure thats the issue. Just dont know where to start. Makin me mad because I can usually diagnose whats going on but this one has me stumped and it frustrating not having the get up and go. Cant barely make it to 55km/h in 4th gear and it wont even get up enough speed to even need to shift to 5th. thanks for all the suggestions. keep em coming
I wouldnt run a ethanol blend in anything. Cat. Converter would be my next guess. Truck starts fine, idles fine, revs fine, sounds fine, no smoke?
yep starts like a dream, idles fine, revs fine. no smoke. so i cant think that it would have anything to do with the fuel line?? i dont know anything about a cat coverter. how does a guy check it out and what to look for??
Cut it out and install a straight pipe to replace it or split it and knock all the crap out of it and weld it back up. If its stopped up your truck will run as if its was lacking power.
would rather not have the worthless thing on there to be honest. so no real way of knowing if thats the issue before i start in on it???
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!’
