Hello all, little bit of back story first. I bought the truck over 2 years ago from Ben at USMiniTrucks down in Houston TX. Truck was super clean and inside and out, exactly like he said. Current mileage is right around 40K miles. The truck has only seen Ethanol-free fuel since I've owned it and also had Seafoam ran through the fuel system and she ran like a champ. As a mechanic, I went over the entire truck and did a slight tune-up involving all the fluids, spark plugs and filters just for piece of mind. The truck is however due for a valve adjustment and timing belt. The truck gets heat cycled once, or more a week. I use it for house projects or other miscellaneous chores. Onto the issue and keep in mind my carburetor knowledge is limited to small engines. A couple months ago I noticed an intermittent stumble only when the truck was a operating temp, and after driving it considerably more, the problem went away on that drive cycle. Which as I learned was a reoccurring procedure. She would also fire right up with zero issues, then at operating temp, going to pull out she would stumble and you'd have to feather the pedal to get the RPMs' up. Once you got moving, she ran great, even under load. The ONLY other issue during that time, if I shut the truck off ie. to run into a store, she would start hard. She'd fire up, stumble a bit then run like a champ once you got going. If it ran for 15-20, it'd clear up with no issue whatsoever. Last night, while taking my son around the neighborhood, it straight up died. Was running fine for the 10 previous minutes. I coasted to the side of the road, got it fired back up and she ran perfect like nothing had happened. I don't feel it's ignition related, and with all these solenoids and an intricate carb, I'm not sure where to start. Thank you for reading and any guidance/advice is welcomed!
when that happens, do you get black smoke out of the exhaust? Test the 2 solenoids, link here https://minitrucktalk.com/threads/s...-airbox-cover-running-rich.21981/#post-127394
Once the weather warms up a bit, I will be removing the carb and thoroughly cleaning it along with replacing both solenoids. I haven't tested them on the truck but will bench test them once the carb is out since they most likely need replaced due to the age of the truck. I'll keep this thread updated with what I find.
is it changing idles properly from cold start up engine to warm engine and from warm engine to AC on?
It idles great regardless of warm or cold engine temps, fires right up actually. Turn the AC on and the idle bumps up several hundred RPM's like normal. I have both sensors on their way from Japan, but I don't believe they will solve the issue. Once I remove the carb, it will be thoroughly cleaned and gone over. I drove the truck last night and did the same drive cycle when it died, and she ran perfect.
Finally had some time to mess with the truck today, with the weather being nice out which meant the kids were occupied enough outdoors to leave me alone. Tested both solenoids while still installed on the carb, Both made their respective noises although the Air Vent solenoid sounded a tad weak, but since this was my first time messing with those particular solenoids, I wasn't sure. It also didn't look like it had ever been replaced, and the truck has 68,000km on it. Ended up replacing the Air Vent solenoid without removing the carb since I already had a new one. That fixed the truck. Looks like the plunger wasn't seating correctly causing an air leak, giving me a lean condition. I always suspected it was a mixture issue, but all the symptoms I found online with these two solenoids didn't seem to relate to my issue. Either way, she's back on the road. Thanks to all who chimed in.
