mitsufan
+1y
Here is the story on this truck. When I got this truck, it was running. When the engine was cold, it would have a misfire to it like it was running on one or two cylinders and die. After a few tries, it would finally run enough to where it would not die. Then, on its own, go from hardly running to the idle jumping to about 2500 rpm staying there for about 3 seconds and running perfectly then idle down and try to stall out and die. After the engine was warm, it would run like a new truck. Well, before I was able to look at this issue my fuel pump went out on me. After a few years, I was able to get the fuel pump replaced and it runs again. I cleaned the tank out (the sock had dry rotted and broke into a million pieces and the fuel pump was rusted). I cleaned the fuel tank blew out the fuel lines from the tank to the fuel rail and removed all the injectors and cleaned them along with the fuel pressure regulator and fuel rail and installed a new fuel filter. Still having the same cold start problem I had before the pump went out. I hooked my scanner to it and found the barometric pressure sensor was showing 12 '' Hg and it should have been reading 28 on this particular day. Put a known good mass airflow sensor on it and no change in the reading. Ordered a rebuilt computer and installed it. Computer works great and is now showing the correct barometric pressure reading (noted the computer board was charred). After installing the computer, started my truck up and still ran like crap. After about a minute of running the check engine light popped on for the TPS sensor (on my old computer I never had a code or light on for this sensor). Tested the sensor and it was indeed bad. Replaced the TPS sensor and adjusted it to specs at idle. Started it back up after sensor install, same problem with the cold engine start. All my temp sensors (engine coolant temp and intake air temp) are showing normal values. Sprayed brake cleaner around the intake to check for vacuum leaks and didnt find any. Went ahead and put new wires plugs rotor cap and button on since I had no idea when they were replaced. I have fixed a lot of little things like the computer barometric pressure reading and TPS and a tune up, but nothing has helped my original problem. I am out of ideas at this point and have spent a lot of time trying to figure this thing out. IAC motor is new as well. It almost seems like the truck is not getting enough fuel then it dumps fuel for a few seconds and repeats and occasionally you can hear it backfiring through the intake maybe once and it has NO throttle response whatsoever just tries to die when you press the gas pedal. After its warmed up I can drive it power brake it ect it runs like new when its warmed up. If anyone has any ideas they would be much appreciated. Im in the process of trying to restore this truck but want to get it running normally first. My grandfather had this truck and got it brand new and it was used for a paper route every day of its life until a few years ago after he died and my uncle used it and didnt take care of it. They just dont make trucks like this anymore and I want to keep it and restore it...too many memories to part with it. Thanks!