[updated:LAST EDITED ON 01-Sep-02 AT 04:54 PM (EST)]Hello all
This is my first post, so I figure I should introduce myself. My name is Mike, my friend's call me Cliff. I have always loved Fords. currently own 2 ford trucks, and 3 mustang 5.0L. I am a fulltime student returning to grad school after working a few years. I sell car parts on ebay full time under the handle fordguy65. It pays for all the bills and for all my toys and I love it.

Anyway, my 1986 F150 XLT 4x4 is giving me problems. It has the 5.0L fuel injected with AOD trans. It idles fine and drives great under light pedal under 2,000 RPMs. Pressing farther down on the pedal or over 2,000 RPMs, it cuts in and out and runs really bad. If I floor it, it will vary between 5,000 and 3,000 RPMs and cuts in and out. It feels like the ignition is cutting in and out, looses tons of power, jumps around all over and backfires.
I ran diagnotics and get the following trouble codes: 25, 34, 44 and 77. 25 I believe to be the knock sensor. Which one is that. That is the second sensor on the right side of the intake under the air cleaner, correct?
Please help me as I am really frustrated with it and can't pull my car trailer again until I get it fixed.
Thanks,
Cliffy.

 

well, welcome abord cliff, nice truck you got there. i'm more of a carb guy myself, but i've had some dealings with efi.

i don't know what all those codes mean, but i've got a pretty common solution to your problem, have you changed the TFI module on your distributor? its a common problem on early FI engines for this thing to go bad and cause all kinds of problems. take your truck to autozone and have it checked out, they will tell you if its your ignition module or not.

hope i helped!

Tim

 

Looks like you did the KOER test(key on engine running). The computer will give you a pulse sometime during the test. When you get this pulse, you are supposed to rev the engine. This is where the code 77 and more than likely the code 25 are coming from. If you do the test correctly, and you still get a code 25, do the test again, but after the pulse(this pulse is called the goose test) take a hammer and rap on the exhaust manifold. If the code(25) goes away, you know the knock sensor is working.