[:@]I have a 1990 Ford F150 XLT Lariat. It has a bad miss. I have had it to the shop and they have put a new injector, and coil in it. I have also replace the plugs, wires, rotor, cap. It seems like it is not running on all 8. If you take it up a sligt incline you have to shift it into 2nd gear to try to make it up. The Exhaust smells really rich. My truck only has 84,000 mile on it. Can someone please point me in a good direction??

 

What do you mean by miss? Does it shake when you try to accelerate? Does it idle well? Does it run at highway speed well?

 

Thanks for the reply,
The truck does not idle properly, it shakes and acts like it is only running on 6 cylinders. When you take off in first, runs bad, second runs worse, third just as bad. I take the interstate to work. 4th gear is what I have to run in. If I put it in 5th, forget it. It just keeps losing speed. If I am on flat ground with no minor grades it runs rough, but will at least go. When you give it gas it just falls flat. I quit running it today. It is to bad. I am afraid itmight leave me sit.
I tried to go through town (lots of stops and starts at lights) it is worse when you have to start and stop. If Ican tell you anymore pleaselet me know.
Thanks

 

Almost sounds like a timing issure. or possible a Mass Air flow Sensor.

 

Try a compression test and even testthe fuel pressure.

 

Also, while it is running, spray some starter fluid, carb. cleaner, etc. around the seals of the intake. If you hear the engine rev, then you have an intake gasket that needs replacing.

 

You could also have a fuel pressure regulator that has a failed diaphram. This will allow excess fuel to enter the intake thru the vacuum port. Pull the vacuum line off of the fuel regulator and check for fuel in the vacuum line. If no fuel is present, then the fuel regulator is probably OK.