O.k. I've got a 92' Ford Ranger. I started it one morning drove to work, ran fine. Went to leave for lunch and it wouldn't start, took me 20 minutes to get it to start. After starting it had no power and when I gave it gas it wanted to die out. It also backfires if I give it to much gas. I've replaced throttle postion sensor, mass air flow sensor, timing chain, I took the exhaust loose from the converter in case it was clogged. It has 121,000 miles on it. I thought it was timing how it was running. Any other suggestions???

 

I can't guarantee anything but my guess is check your fuel system, possibly fuel pump, clogged fuel filter, or maybe fuel pressure regulator. I'm leaning more towards the fuel pump, which is an in the tank pump. in order to change it you have to either drop the tank and on the top there is an access point to where you can get at the pump. I did this in my truck and i would highly reccoment taking the box off the truck because it would save so many headaches. The reason why i think its the fuel pump is because when a fuel pump wears out, it will usually work good until it warms up which could take 5 - 10 mins, depending on the temperature outside. and then when the pump warms up it starts losing its pressure and thus you don't get pressure to the injection system. Maybe try a 3 dollar can of injector cleaner also, just a thought.

 

From what I've been reading I think I'm going to try the cam sensor next. I did change the fuel pump within the last year or two so I really don't think it's that. I know what you mean about being a headache.