1992 f150 4.9 cranks but won't start etc.

[TFB1]

Originally Posted By: Black_Thunder
if people would pay attention to what i said about the fuel pump running all the time when the key is on and the engine is off and seeing that i had a bad eec they would realize its not something easy thats why i posted it in here to begin with.


Agreed, most don't have a clue what a continually running means in a in a Ford EEC-IV system... BUT generally you should have multiple codes or no code output at all and yours doesn't seem to fit into that category... The continual running pump could just be a sticking F/P relay that's fed power from the EEC relay...

And for those who haven seen a leaking capacitor in a Ford EEC-IV computer, here's what we're talking about...

When mine had the bad cap it ran so rich when cold that it would foul plugs, why I mentioned checking plugs as if that was case it won't make any difference how old/new they are...

 

[Black_Thunder]

Originally Posted By: TFB1
Originally Posted By: Black_Thunder
if people would pay attention to what i said about the fuel pump running all the time when the key is on and the engine is off and seeing that i had a bad eec they would realize its not something easy thats why i posted it in here to begin with.


Agreed, most don't have a clue what a continually running means in a in a Ford EEC-IV system... BUT generally you should have multiple codes or no code output at all and yours doesn't seem to fit into that category... The continual running pump could just be a sticking F/P relay that's fed power from the EEC relay...

And for those who haven seen a leaking capacitor in a Ford EEC-IV computer, here's what we're talking about...

When mine had the bad cap it ran so rich when cold that it would foul plugs, why I mentioned checking plugs as if that was case it won't make any difference how old/new they are...

thanks for your input and understanding what i'm talking about. that picture is shows exactly what the capacitors do when they leak and go bad.

ok after i try the next eec i will check the relays etc and then i'm going to yank out the plugs etc. and go from there

 

[Black_Thunder]

never did update this as i was busy and didn't do anything with it until last night.

I swapped out the eec again and yanked the plugs and found them fouled

replaced all 6 plugs hooked up the battery, cranked it over and it started and ran fine.

I still think something was wrong with the first reman eec that i got as the fuel pump was still running constant with the key on and engine off.

but now its good to go.

thanks above about the over-fueling issue/fouled plugs suggestion.

i also changed the oil and you could tell there was fuel in the oil etc. from when the eec took a dump and was running rich etc.

 

[TFB1]

Originally Posted By: Black_Thunder


I still think something was wrong with the first reman eec that i got as the fuel pump was still running constant with the key on and engine off.

but now its good to go.

Yep sounds like the replacement PCM was defective... Now at 20-25 years, the old electronics are failing(mine was 18 yr old), especially those small electrolytic caps... I replaced those components every day back when I was repairing TV...

Glad to hear it's OK now...

 

[mk378]

The electrolyte that leaks out is corrosive and can damage the copper traces on the board or other parts. Even if the board is not damaged yet, it is important to clean off the residue so it doesn't happen in the future.