Hi all, the Mitsubishi Minicab forum is dead so I figured I'd ask for advice here. My 1995 Mitsubishi Minicab with a carbureted 3G83 engine overheated and died in January 2022. I had just picked it up from the port and filled it with a full tank of gas. It's been sitting in my driveway since then, so for approximately two years and six months. It showed all the symptoms of a bad head gasket, and no amount of cranking would start the engine in the slightest, so I've recently found enough free time to remove the engine, resurface the head, replace the head gasket, and put the engine back in. When I cranked the engine for the first time it ran for about 3 seconds and sputtered out. Tried a few more times with starter fluid sprayed into the air intake, ran for maybe 7 seconds and died, and now it won't start at all. The engine cranks forever but never starts. I don't see any gummy stuff clogging anything, the gas looks and smells like gas, and it sprays without issue into the air intake valve on the carburetor. So now I'm wondering what's wrong and if perhaps someone with more experience could give advice on what could be wrong here. Is it possible that 2.5 year old gasoline is old enough that it's completely bad and won't get the engine started? Has anyone experienced this? Is there something else that I should consider since it's been reassembled, and sitting without running for so long?
2 years old gas should still ignite, albeit poorly. Ideally, you put fresh gas in to get best results. Since it run-ish w starting fluid, the timing and ignition is likely fine. Then, I'd check the fuel system to make sure gas is coming up to the carb. You said "it sprays without issue into the air intake valve". Does that mean gas IS getting to the carb, is filling the bowl, etc? And "now it won't start at all", meaning with or without starting fluid? If it won't start w starting fluid, you may need to recheck ignition and timing
Alright so just to be safe I siphoned almost all (if not all) of the old gas out, dumped a can of Sea Foam into the tank, and added 5 gallons of fresh regular gasoline. I didn't realize it was pissing this much gas, though. (Video below) I assume that isn't right. lol. It's flowing out of the small holes above the primary valve hole, rather than just the tiny jet at the base. I couldn't see how bad it was because the air intake hose was assembled and caught most of the flow and it was just pooling in there.
that's def not good. when you can see THAT MUCH gas, coming out the wrong end of the carb, your carb's needle valve is likely stuck open, so it just keeps filling the bowl. i don't know if you can get to the carb bowl without taking it off the engine, but if you can, you could try to free up / clean / replace the needle valve. if you can't, then it'll be worth the trouble to clean the whole carb. I'm nor familiar with this carb (or frankly even my own Daihatsu's carb), but have rebuilt ones for motorcycle and classic mini. but at least your fuel pump and lines and filter are good...
Alright so I spent the last two days cleaning out the carb without removing it (aka spraying a bunch of carb cleaner and straight Seafoam engine treatment into it). I also added some Techron to the gas tank (about half a bottle, because there was already a whole can of Seafoam in there and only 5 gallons of gas). After cranking it and having it run for 10 seconds before dying a bunch of times, I hooked up compressed air to the fuel inlet hose and sprayed 90-100 PSI into it, after which a bunch of brown liquid dripped out and I knew I had done something right. Started up fine immediately after that. So the jets were just clogged. Only problem now is the smoke. (Video below) I -think- this is the Seafoam that I sprayed into the carburetor burning off slowly. I hosed quite a bit down the throat of the carb in my desperate attempts to unclog it. From what I've read and seen, the smoke will be white if you put a shit ton of Seafoam directly into the air intake. However, I drove the car around town for 45 minutes and it didn't stop smoking. It feels like it's accelerating fine, so hopefully something else isn't pissing into the combustion chambers. I currently just have distilled water and coolant system flush in the coolant system, not actual coolant, and it doesn't really smell like coolant to me. Is there another obvious thing I should look into here? Edit: I still need to re-adjust the valve clearance when the engine is warm, might be contributing to the problem.
MrJ, I think you're on the right track, as the coolant flush gets diluted it gets harder to smell the coolant. Plus your nose can get a little more acclimated to it. Once you put the coolant in you'll be able to smell it again. As far as the white smoke, just keep running it and adding fresh fuel as it takes a while to burn it through. Good Luck, Limestone
Thats just the techron and seafoam burning off. Thats one way to clean out the gunk on the bowl. If you let any gas with ethanol in it sit for longer than about a year, it will gum up anywhere it sits and evaporates. Which is usually in the carb passages and bowls. Gas with no ethanol, if sealed up, will last a long time and even if it has evaporated some it won't leave gunk behind.
Just a quick update, the smoke has completely cleared after driving it around for a few days. Runs perfectly and there's no coolant or oil consumption, and the gas still has seafoam and techron in it. I do think the catalytic converter had either rain or coolant trapped in it because it sloshed around when I was reinstalling it onto my exhaust manifold so that probably contributed to the problem. But it's great now! Thanks!
