660cc U42T, started acting strangely. Step on the gas, it staggers and loses power. Back off, and you slowly gain speed. Sometimes, it just works fine for a few minutes, then starts stuttering again when you try to accelerate. No smoke, brand new fuel pump. One other interesting thing, when it's cold out it won't even start. Cranks over fine but no fuel smell, won't fire up. Not talking real cold, like -10C. Plug it in for half an hour, it starts first turn of the key. Don't know if that's related. Any suggestions as to what to start looking at?
having similiar problems with mine and I have tried everything: swapped carb, checked and cleaned choke lines, new plugs, cap, rotor, fuel pump is working great, choke working good, new ignition coil, air filter is clean, vacuum lines good, and still none of it has made any difference. If you figure yours out let me know.
Lack of power problems I've mentioned before about your engines timing, and checking your distributor and making sure it is operating properly. If this has been a concern and your fuel system has been checked, check your ignition system and distributor. If your distributor is equiped with a vaccum advance check it operation if you can access your distributor pull the cap remove the vac hose from the vac advance, attach a longer piece of hose suck on the hose and see if the advance is working. If you aren't afraid to remove the distributor from the engine it's much easier to check the inner workings. If it has a vac advance it will have an advance plate it hooks to, this should move when you apply vac to the hose(suck on it) if it doesn't move remove the advance and check it by itself, if ok check the plate to see if it's froze up not moving. There is most likely a mechanical advance in the lower part of the dist body it has weights and springs when you twist the rotor they should travel outward, unless your mini is a late model with fuel injection your distributor timing isn't controlled by a computer, A good working distributor is critical for proper engine operation, if the timing doesn't work right your truck will run like a rat dragging a brick!
The distributor was taken apart and cleaned, a lot of rust on it. New plugs and plug wires and a little tuning. The mechanic didn't want to give it back until he thought it ran perfect (ie he was having too much fun test driving it!). Now runs great, more torque than it had when I got it and I wound it out to 105 kmh on the new 13" studdeds, about the same as I got on the 12" originals but the speedo's probably out about 7-10%. Now she needs a wash, deck coat and a coat of paint. What's a shame is that this all started the very day I put the new wheels on, and I must remove them by law May 1. There isn't even any snow left now!
it sounds like your not getting enough gas into the engine. have you checked the pilot jet in the carb?, if this get any gunk in it even the smallest amount will cause trouble, and it sounds like this is what you are having. if the truck sits or you get dirt in the gas, its not the dirt that gets to you carb, its the fungus in the dirt that grows in your carb. also check to make sure that your heat riser is working properly. hope this helps wyatt
Seems like we are getting crossed messages, my reply was in general to many guys having power problems, everyone seems to think its always fuel related, maybe at times, but ignition timing plays a big roll in engine performance, that is why I suggested to check distributor for proper operation. The earlier mini's are pretty basic, carb's and distributors with mechanical and vaccum advances. For the guys that might not understand how the timing effects the engine performance, start your engine, access the dist. (mark the dist.housing and block before you start) loosen the hold down bolt slightly, start the engine raise the rpm's and hold rpm's steady, now start to twist the dist. housing and listen to the engine. When you retard the timing the engine will slow down, advance it and it speeds up, this is what the dist. does with help from mechanical and vac advance, the engine has a base timing setting which needs to be set to factory spec's after that if the dist is working like it should, the engine will perform well.
i know this is an old thread but hopefully someone still has some more information on it i am experiencing a similar issue i am only loosing power on low end. 1st gear mainly did a full rebuild even replaced the clutch in my 93 mitz it ran fine for about two to three weeks on its longest voyage it started loosing power to the point it was having to be downshifted to keep up rpms to get back to the house about 100 yards from the house the engine died 15 min later fired back up and the power loss encured only on the low end power. you floor it and you can get it moving and then once underway mid and top end power is their. i am at a loss as to what it can be at this point sometimes after it warms up its fine and the power is their
