My truck is a weekend driver, I start it every three or four days, it is basically a toy! The first thing I noticed was the fuel pump had a high pitched whine, more than it ever had, it did not stop pumping after a few seconds, and it cranked over without starting. Because of the high pitch sound from the fuel pump and it's continuous running I believed the fuel pump was bad.
I replaced the fuel pump but that did not fix it, it will start with a shot of starting fluid. After I get it started it will go through it is warm up stage and idle fine for a few seconds to a minute. Then for some unknown reason the idle will go up to around 1600-1800 rpm's and black smoke will come from the exhaust. It will stay like that for however long then it will go back to idling perfect to an undetermined amount of time until it starts all over again, heightened idle and black smoke, then back to fine idle and no smoke. Maybe, I shut it off if I am unable to get it to idle right. Also, during this time of high idle and black smoke the engine compartment feels hotter, do not know why but it does.
I have no "check engine" light until it starts the high idle/black smoke, when it idles right the check engine light turns off. I have no error codes in the current or extended memory and my system is the EEC-IV, not OBD.
I have replaced fuel pump, IAC motor, MAP sensor, fuel pressure regulator, fuel filter, cleaned fuel injectors/throttle body/plenum and installed new gaskets from plenum up. The EGR and smog system was removed long ago by the previous owner. I have had my truck since 2002 and have never had a problem I could not diagnose, until now! Please help me get my truck running right again!
have the same problem?
Monday, May 1st, 2017 AT 9:34 AM