I have a 87 F-150 4x4 with 5.0 engine and manual trans. that is driving me crazy. when the engine is cold it runs rough and smokes black out of tail pipe.when taking off from a stop engine will try to die. if it dies I will have to crank it for at least 15 sec before it will start.also truck idles at 900 to 1300 rpm.so far I have replaced plugs, wires, cap&rotor, ect sensor, tps and cleaned injectors.The only code I get is a 44 thermactor air sys. fault.according to what little info I have this fault won't cause this problem.I have checked for vaccum leaks and found none.egr is working correctly.fuel press is 35 at idle and jumps to 40 when throttle is snapped.fuel press doesn't drop when engine dies.engine runs fine other than hi idle once it reaches operating temp.any ideas?

 

Black smoke tells me you are running rich. If your O2 sensor is worn out it could be giving misleading air/fuel mixture info to the EEC computer. Try replacing the O2 sensor. I recently bought one wholesale for my Camaro and it was $25. A buddy spent about $50 for his retail. Find out whether you have one O2 sensor or 2 (one on each side). They should be somewhere just downstream of the exhaust manifolds. Be careful not to strip the holes when removing. Or, you said that you have a thermactor error message. If it is or isn't blowing air down the exhaust the way it should, the reading the O2 sensor gives the computer could fool it into richening the mixture. Maybe you have a check valve that should prevent the air injection until the engine is warm that is not operating. It seems to me the error is relavent and requires attention.

 

From my experience,black smoke on a fuel injected motor will usually be a MAP sensor problem IF,you checked fuel pressure at the fuel rail; verified the operation of the TPS; tightened intake bolts & checked all vacuum hoses including power brake.There are many other things here,too much to list,so you'll have to do a little & post back a little. Start back with the basics like new plugs,new fuel filter & scrub the throttle bores.If you got another Ford somewhere you can swap MAP sensors for a test before you purchase one,if you can't take voltage & vacuum readings.
Phillip

 

I have checked every thing.ecm is getting correct signals from sensors but it is not controlling air fuel ratio like it should.I guess some idiot at Ford thought that 12 years is too long to make this ecm because it has been discontinued. ecm is not available after market either.if someone knows where I can find one I would appreciate it.part# E7TF-12A650-AN1B.