Howdy All
'87 F150 XLT 302 AOD EFI

I was running errands and needed some extra go, so I hammered down WOT and the truck died, quietly, lost everything at once but I was able to roll to a red light and had the wife come and push me to a parking lot (with another vehicle, she's not that strong, not even close).
So far, cranking fine, Battery 12.8V, Fuel rail 35 PSI cranking, Coil getting 6.2 VDC and pulsing while cranking, rotor turns with crankshaft.
Had to take the battery in for a charge (drained by diagnostics) before I was able to pull a plug to test for spark.
Codes:
21 O
24 O
34 O
84 O
41 C
34 C

I did notice the battery gauge was reading very low a few days ago while driving with the heater on, went right back to normal when I turned the heat off. Also, the key on "ding" sporadically sounds under powered, lower pitch, longer duration.

Anyone have any ideas? I than you kindly in advance.

 

Without the truck up to temperature, you'll get codes like that.
Check out posts 6 and 7 at this thread Ground Points - Ford Truck Enthusiasts Forums https://www.ford-trucks.com/forums/1...nd-points.html
Your ground points will be slightly different, because your truck is an '87.
These two grounds need to be connected to the battery negative terminal. If you have this style of battery terminals, they could be the whole problem.


Disassemble, clean and reasonably tighten the grounds in the link I posted.
Don't underestimate the problems that the main ground cable can cause. It runs from the battery negative terminal to the engine block and frame. It can corrode internally and need replacement.
Check out your ignition switch (not the key cylinder), that's mounted on top of the steering column and connected to the key cylinder by a linkage rod.
If you lower your steering column, be careful to disconnect your shift indicator cable.
The ignition switches are known to separate and fail.
Stand by the truck with the hood open, and rotate the key to the run position. You should hear the ECM and fuel pump relays click on, then after about two seconds, the fuel pump relay should click off.
If the fuel pumps run constantly, that's an indication of a failure in the computer circuit board. There are blue capacitors on the board that are pretty easy to replace.
The computer comes out by pulling it into the cab, after loosening the 10 mm head bolt, at the center of the 60 pin connector and unplugging the connector.
The computer is behind the driver's side kick panel by the emergency brake pedal.

 

Duplicate post

 

How are you pulling codes?

 

6.2 volts to the coil sounds a bit low. i am thinking low system voltage. how old is the charging system and cables?

 

Back in the 90’s, I had just gotten off the highway and made my way over to the left turn lane to turn at the light when the truck (‘87 Bronco/302/C6) shut off and would not restart. At that point it had, I think, about 180K miles on it. The problem turned out to be that the nylon camshaft gear had worn out. If you take the cap off the distributor and crank the engine is the rotor turning?

 

YES, it is in the first post.

 

Or in the original poster's case, maybe the roll pin sheared and the timing is off?

 

Oops. Missed that part

 

Do you have spark at the cap? Do you have spark at the plug? Do you have injector pulse?

 

Thanks everyone for the responses. I am just now able to take all your suggestions and go look at the truck again and see about pulling it home if I can't drive it here. I'll post what I find when I find it.

 

Again, thanks so much. I was able to check the spark at the plugs and they were very weak. I had an old coil sitting around, swapped it out and it started right up.

 

Thanks for reporting back with the fix! Not many do and then someone stumbles across your post later on and is like wth was the solution.

 

For future reference the Title should read Found on Roadside Dead..........