I just bought an '87 ranger xlt 2.9 efi with a4ld trans. I ran the codes, it gives 89, tcc lock out solenoid circuit failure. well I found the problem, the harness is not connected. Trans has a 3 wire connector, truck has 2 wire connector. What would i need to do to correct this problem, short of changing trans? which wires can be spliced to which connectors to solve problem? Also truck runs good then all of the sudden runs rich, puts out black smoke and looses power, I can flip the ignition switch off and back on, while driving, and the engine runs like a new one for a few moments, then it startys running rich again. codes give me egr and o2. Replaced erg valve and pressure solenoid, will soon replace o2. Is there a specific problem other than mentioned that will cause this? BTW this is a very informative forum I really like this place and plan to stay, any help on this situation will be really appreciated.

 

First, I would suggest a set of wiring diagrams.
Because the transmission has three connectors for that plug, it must be an '88 or later A4LD, which uses the EEC-IV computer to control both the TCC lockup and 3-4 shift. An '87 A4LD uses EEC-IV to control TCC lockup, and engine vacuum to control the 3-4 shift (Do you have 4th gear?) Basically, you are going to need a wiring diagram for your '87 to identify wires, and a wiring diagram for a later A4LD (Can you figure out what year A4LD you do have?) to determine which lead to connect the power wire to and which lead to connect the TCC solenoid to computer wire. If you don't have 4th gear, you might take this opportunity to also wire in a means of controlling the 3-4 shift.
That said, it might be easier to go to the junkyard and swipe a connector off of a newer A4LD, splice the three wire connector in place of your 2 wire connector, then figure out how you want to do the 3-4 shift thing.

 

sounds like a winner on the tranny. then i can switch to od on highway and 3rd for city. thanks mrshorty. now all i have to do is figure out the engine running rough problem. changing o2 sensor right now. hope it takes care of it.

 

as far as i can figure, it is running closed loop til warmup, and if o2 not sending to computer, then when the temp sensors tell the computer the engine is warm it switches to open loop and reads not warm from the o2, which means rich with warm engine. when i turn the key on and off while running (driving) computer resets to closed loop, which means factory preset readings, and the engine runs great for a very short while.

 

well for those of you out there who might be interested, the o2 sensor cured the engine problem, now just need to find a simple cure for the tranny problem.