I have a 1992 B2600i. It was given to me and I know about issues with the fuel pump on it's way out. And when I first got the truck there were no issues, other than having to pull over to vent the gas tank.
When the weather started to cool off but not yet cold, I could no longer just start up and go. It idled fine (1500rpm) but when I gave it gave gas it would drop down to 500rpm or so and when I took my foot off of the gas, it rose back up to 1500rpm.after maybe 15 min. or so, I could give it gas and it wouldn't die down and I could take off. I could put up with this for a while.
A while has passed and I can't take it, Now I have trouble even starting it. I have to pump the gas four or five times, take my foot off of the gas and then try to start it. It would catch but a no go. I then started to just leave the key fully turned to keep the starter running and it if caught, I'd let the key go. Id' still have to let it idle for quite awhile.
So, thinking it may be a thermal sensor, I'd let the truck idle for a bit and then turn it off. I was thinking that the engine compartment would be warming up the sensors. Sometimes it would work and sometimes, not! Since my truck is too old to do a OBD reading, I have to shoot in the dark.I took of the mass air flow and cleaned it with that spray stuff. Both ends were covered in a black like soot. I made sure it was clean and put it back on. My next thought was if the mass air sensor looks like this then what does the air filter look like? I went it to the auto parts store and had to order one. My next escapade will be to completely tear down the air intake system and fully clean it, including the throttle body and all. I have one question and I can't find the answer to it anywhere!!!!! Behind the air intake "pipe" there's a sensor coming out of it going into a black box and I found the name or "RESONANCE CHAMBER"!!!! Does anyone here have a clue what it's for and it's purpose????? Thank you for any and all help/suggestion that you may be able to contribute!!!!!