1986 2.9 running bad

[eric okelley]

hello all, i have 86 ranger 2.9 5 speed it will start and idle but misses and blows black smoke. also the fuel pump runs constantly with koeo. and when i hook up my code reader to the diag plugs it will not preform tests and just have 000 on the lcd. i have replaced ect,coil,cap,rotor plugs,(they are fouled again),wires, icm, and map. checked iac tps they seem ok. put timing light on all plug wires and can see the miss in every wire, so i put it on the coil wire and can see it in it too. i am thinking its in the ecm.(with the engine miss and fuel pump issue) am i missing something? any input would be very helpful. thanks eric

 

[RustedRanger]

Mine had a bad plug in to the coil...and the coil was weak. The idle on mine would jump around and miss when the plug in was jiggled around. I only found this out because a friend put it on his diagnostic computer....that and he is very good at auto electrics. Worth checking.

 

[eric okelley]

rustedranger, did your friends diag computer hook to the diag connector on the pass side firewall? are you talking about the electrical plug in or the coil wire attaches to?

 

[RustedRanger]

The electrical plug in to the coil. He connected his comp to each sensor and the coil and watched to see how they was working,when a sensor is working right it showed a smooth sweep on the graph readout. When hooked to the coil it jumped around when the plug in was jiggled around. I had cleaned as many plugins as I could but then it would not start at all even though the plug in for the coil looked like new inside. From what you said it might be the ECM since it sounds like it runs messed up all the time and you can't get codes. If you can afford it I would get it put on diagnostic computer to keep from replacing parts you don't need.

 

[eric okelley]

thanks man the ecm is kinda what ive narrowed it down to. if anyone else has any ideas im all ears...........

 

[eric okelley]

just to let everyone know a new ecm fixed all my problems, the research i did told me that ALL ecms pre 1996 had electronics that were known to fail after several years of use. so dont completly rule out ecm when you are having problems