Question on my 4x4 f150 with 5.8 and e40d 1994 yr. Can you check or test the computer . is there a simple way or test to check if it is functioning correctly?
Thanks
Grumpy

 

I don't know of any one test that will tell if the PCM is working correctly.
Possibly certain codes might tell you that.
Most times we back trace from the troubled area and confirm all is well until we end up at the computer.

 

thanks Hanky

 

Now after cleaning all the connectors and putting on electric type grease I found the problem improved but not fully solved. After I tried the unhooking battery and trying this fix on the pcm which seems to have helped with the final problem. I say seems because this thing likes to come and go.
Question is what can you do about a salvage pcm? can you pull one out of a truck equipped the same? or do the numbers or some in the number on the pcm tell you they are compatable? I never got into a computer but do know the expense.
Thanks
Grumpy

 

The "computers" for pre '96 years were usually not that expensive and some differed from year to year. They are easy to replace and require no kind of reprogramming.
Most places don't have the means to check the OBD I computers for any codes.
"Thexton" makes a sweet little tool (#443) that made it very easy to get "Hard codes , continuous codes and also do dynamic testing of the vehicle and computer".
It used to sell for under $20.00. . If you are going to keep the vehicle , I would consider purchasing one. Most auto supply stores can usually get one.for you.
It can save you quite a bit of trouble and the pre 96 Ford vehicle computers were able to do running (Dynamic) testing and provide the codes if there were any problem(s).
It didn't provide actual numbers.but you counted the flashes of a little LED. You could also clear codes with it.

 

Was the old style MLPS ever upgraded?

 

MLPS ?? ok what are we talking of I am not sure. I took off the part on the side of the tranny ford calls a manual shift lever sensor and the parts store had one it called it the neutral safty switch. That part I put back on and tried the starting in gears and it seems to do as ordered so no that I didn't replace.
Is this the same as MLPS?
Thanks for all the continued help.
Grumpy

 

Ford updated the old style position sensor due to issues with moisture intrusion causing corrosion. The replacement included the new design sensor and harness pigtail..

 

One thing worth doing. Take the cover off your ECM and take a look. Back in the late 80's thru early 90's, there were faulty electrolytic capacitors being installed in all types of electronic equipment that weren't up to the job. If you see any capacitors either leaking or bulged out, it is bad and will cause problems. Some people will just replace them all and reuse their ECM.Of course you have to have good soldering skills to do it.Blob soldering won't cut it.

 

It seems I keep getting more questions: the pcm I pulled and cleaned the plug and such and the only major problem im finding now is the idol is at around 800 .
I assume the pcm also controls the idol on the engine is this correct?? I am going to try and find a oriley pcm this week and give it a try, I did see a spot inside the pcm that was not right, looked like a little can in it might have leaked.
Thanks Grumpy