> Do PCM`s go bad on a 1988 Ford F-150 4.9L? I believe mine is no good.
> Thanks,
>
> ...mfat
<<Trust me, have someone
> with a scan tool check it out and see. Hell the truck just might need a
> tune up. It is 18yr old afterall.. LOL >>
Hey!
Well here`s the scoop:
I just bought a 1988 Ford F-150 with a 4.9L 5 speed, and It has this crazy
electrical problem. I knew that the truck wouldn`t run before I bought it,
but the price was right ($500.00) with 118,000. The truck will not start and
has weak spark. The distributor module has been replaced with no luck. If I
leave the key in the "On Position" the fuel pump will run erratically, and
the fuel pump relay "clicks" very quickly and erratic. Under the washer
bottle, there is a wire harness that runs under it, and branches off on top
of the left front wheel well with 3 connectors. The biggest connector with
12 pins (roughly) was corroded. I cleaned it, and still no luck. So then I
inspected the other two connectors that are right next to the 12 pin
connector, and they appear ok. Is there a common break in the harness? In
that harness, is the wiring for the coil/distributor/and fuel pump together?
Visually inspecting the harness, it looks ok. The truck seems to "flood"
from cranking because the fuel pump is always energized. Smoke does come out
the tail pipe, so there is little spark. I replaced the distributor module,
and the pickup inside the distributor, still no go. I replaced both EEC
relay, and the fuel pump relay, still no go. SO it leeds me to believe it`s
the PCM. I took it apart, and nothing looks burned, but what else could it
be? I have all my grounds, and power sources at the relays and so forth. I
even replaced the pigtail on the front fuel pump. I`m at a loss!!!!!!!!!!
Thanks,
...mfat
>> Do PCM`s go bad on a 1988 Ford F-150 4.9L? I believe mine is no good.
>> Thanks,
[quoted text clipped - 10 lines]
> me, have someone with a scan tool check it out and see. Hell the truck
> just might need a tune up. It is 18yr old afterall.. LOL
Mfatoldsun - 31 Mar 2006 23:49 GMT
Guys,
The PCM fixed the problem. It was causing loss of ground throught the
harness. I got a junk yard PCM for $70.00 she fired right up. SO
HAPPY!!!!!!!!!!!!
!!!!!!!!!!!!FORD!!!!!!!!!!!!!!!!!!
...mfat
> <<Trust me, have someone
>> with a scan tool check it out and see. Hell the truck just might need a
[quoted text clipped - 45 lines]
>> Trust me, have someone with a scan tool check it out and see. Hell the
>> truck just might need a tune up. It is 18yr old afterall.. LOL