89 Mighty Max sputtering.

I have a 1989 Mighty Max SPX Macro Cab 4x4 a 5 speed manual transmission and I believe it has the 2.6L motor. It was just given to me as a gift from my dad who no longer needed it. I live in MI and was driving back from TN with my new gift (not appreciating that gift now!) and the truck when hitting the big hills started to sputter just a little a few times and I would have to let off the gas a little to stop the sputtering/hesitation. The truck was terribly underpowered and could not maintain the speed limit over the hills. I would hit them at 80 and by the time I got to the top I was going 50. I drove 65MPH most of the time except when coming up on a big hill with a steep grade. I got about 15MPG as well and according to my pops it has gotten about 15MPG since he bought it 10 years ago.

I then stopped for gas a while later and then got back on the E-way. I went 50 miles and the truck began to sputter badly and would not go over 30 MPH. The harder you push the gas the worse it is. If you lightly press the gas it will maintain about 50 MPH as long as you are on a flat road with no incline. If you push the gas past 1/4 it will shudder and act like its out of fuel. It was also noted by my wife who was driving behind me that the truck was puffing black smoke. When I stopped at an exit I took the air breather off the carb and noticed that the air filter felt wet. I removed it and there was water around the air breather cover plate that sits on top of the carb. I soaked up the little bit of water and removed the air filter. I put 2 cans of dry gas in the tank but it did not help. I removed the fuel filter and it had a cloudy and slightly orange tint to the fuel I dumped out of it. I put a new filter on at that point. Nothing I did seemed to help.

My father said when he bought the truck 12 years ago it would not go over 50MPH and sputtered just as I am describing. He could not fix it because the Carb is so complicated. He had it fixed but does not know what it was that was wrong.

Does anyone here know what the issue might be besides dirty fuel? Also my opinion is when the truck was running fine that the truck is way under powered. I know it has a small 109HP motor but it should maintain speed better in the hills. Also when I look up this trucks fuel economy it shows 18 city and 21 highway. This truck since my dad owned it never got better than 16MPG no matter how or where it was driven. This leads me to believe the carb has never been quite right since my dad got the truck? What fuel economy are you all seeing with yours?

sounds like the water choke is plugged up and not letting the choke blade open so you are running rich there are two water hoses (5/16th) going to the carb if you remove them and use compressed air to blow out the choke it will help

The choke is open when I look in the carb running or not running. The butterfly is wide open on both sides of the carb running or not running. Am I missing the point in what you are speaking about? Is there something that can be plugged that I am unaware of and the butterfly can still be open?

It is defiantly running rich. I would say it is loading up on fuel big time. At least that's how it feels. I can also feel it puttering when I stick my hand near the exhaust pipe at the rear of the truck. You cant hear it missing but it feels like it is missing a little when you feel the exhaust pressure at the tail pipe.

What has me wondering is the water that was around the air breather and filter. It was at least 6 Tablespoons of water on the lip inside the air breather and that lip is right against the edge of the carb opening and it had easy acess into the Carb. Maybe water got under it and into the electronics of the carb as well? There are two wires going into it under the Air cover pan and I am not sure but I would hazard a guess that they control the choke?

If water got into the carb opening and past the butterfly's wouldn't it just be burned off and eventually pushed out. The water at the bottom of the air breather pan may just be throwing me off as the culprit when it in fact it is unrelated to the actual issue. I am still trying to figure out how the water got in there and if it is the problem or not. It was raining and the windshield before I left with it was leaking inside the cab very badly. I repaired it but maybe that's how it somehow got access to the air breather. It was also raining when I was driving it home as well.

On a side note my pops had to replace some electronic piece in the distributor. I believe he said it was under the distributer cap or under the distributer rotor. He said it cost over 100 dollars. He did this because it had no spark at all and had tracked the issue to that failed part. After he fixed that part it still would not run right. He eventually had to adjust the timing and said when he did that he discovered it was way out of time. I looked and everything is tight and the cap has not moved at all. MAYBE this is related to the current problem as well. Maybe it jumped time? I still cannot figure out why he would have needed to adjust the timing. It should have been right when the truck was running. He marked it before removing anything and put it back where it was. So once he did that it should not have needed to be timed. He said it did for some reason and that it was way off even though everything was put back in the same place. He said it was still off just a little after he timed it but it was very close.

It seemed to run fine before it started hesitating, loosing power and sputtering. The only thing I thought I would need to fix was the transmission. It does not like to down shift and to up shift it w/o grinding gears you have to run the tachometer up to about 3100 RPMs. If you try to shift at 23 or 2400 RPMs it will not even go into gear. When you down shift from 5th to 4th it grinds very quickly and lightly before going into 4th. It acts like something is out of sync. I have yet to study up on this truck so I am like an uneducated child right now. Once I get it home I can try to read the repair book and track down the issues. In the mean time I hoped someone else had these same issues and may know the exact problem do to experience.