i've got a 1987 f-150 4x4 w/ 4.9 EFI 4 speed/granny short box.i bought it for a woods truck. it's got some problems.i can't get the codes from the computer.the check engine light either is blown or just does'nt work.i went to the ford fuel injection.com web site and got the instructions how to check the codes and did what they told me to do,and still can't get the codes.i've found the DLC and the STI set up my meter an still can't get the needle to move.here is my problem,the truck runs great for about an hour or so then coughs a couple of times and dies.it starts back up,but when i press the gas a little it dies again.i can wait about 20 min. start it up and it will run about 300 yds. and die.or i can wait several hours and it will run for another hour or so then it dies.i've taken it to a mech. friend to check the EGR set up,and he said all the components checked out ok.i'm at my wits end about now.this is what i've replaced so farall) fluids,plugs,wires,distributor cap,rotor,pick-up coil,ignition control mod,(all) filters,starter,starter relay,ignition coil,temp.sensor,idle air control valve,throttle body base gasket,oxygen sensor,(all) vac.hoses,map sensor,eec relay,fuel pump relay, high pressure fuel pump,rear tank low pressure fuel pump.i know it's a book,thanks for any and all advise.

 

Try changing the computer.

 

thanks,i'll check into it.

 

The Check Engine light in 87 year trucks was not wired for some reason. My truck is the same way.

 

what will changing the computer do? i don't see it.i wonder why ford didn't have the check engine light in the 87 f-150.

 

It might fix it, you have changed everything else.

 

The red engine light should be hooked up but for some reason the yellow engine light isn't.You should be able to tell if the red light is hooked up by turning the ignition on, it should stay lit till u start the engine

 

If you don't have a working check engine light (you checked the bulb, right?) and you aren't getting codes from the diagnostic connector either then I really think your computer is fried.

 

The '87 didn't come with a socket in the check engine light position to put a bulb in, nor did it have a wire to the printed circuit on the instrument cluster. I have no idea why.

The red "Engine" light is just a warning for low oil pressure on '87 trucks.

 

That is just bizarre.

Regardless, if he's not getting any codes with a voltmeter at the diagnostic connector, it's not a good sign.

 

I agree with both

 

thanks for the input guys,i run the truck around town today,but it was less then an hour.i still don't understand if the computer is bad wouldn't it not run at all?any and all help would be great,thanks again.

 

PCMs aren't like light bulbs. Light bulbs either work or don't work. PCMs can "sorta" work. Just because you truck runs ok most of the time doesn't mean the computer isn't bad.

Can you go into a little more detail on how you are trying to pull codes? If you aren't able to get any codes at all, even a system pass code (11), then you either have a wiring problem or the computer is fried.

 

first i tried to get the codes with check engine,no luck.i now know why.then i went to the diagnostic connector ,with what i know is a bad meter,got nothin'.i bought a OBD1 to hook up,but haven't had a chance to check into in yet.i hope it works,so i can figure out what it wrong.

 

i didn' know the meter was bad at the time.