93 Explorer (only one motor that year). When I turn the key on (not the engine) the fuel pump comes on (as it should), but does not shut off.
Car does not run - it did for two days - idle was erratic, Check Engine Light stayed on, car would buck, cut off, sputter - but, now it will not start.

Here is what I have done:
Changed fuel filter.
went to junkyard and grabbed two fuel pressure regulators and a 8 relays.
Changed the fuel pressure regulator (twice) and Fuel Pump Relay and EEC relay a bunch of times.
Pulled plugs (they were black [sooty]) - cleaned them and put them back on.
Pulled power distribution box off and check for any obvious loose connections on the back side.
Checked all vacuum hoses and connections - all seems good.
Rented a fuel pressure gauge and checked fuel pressure at fuel rail - with key on (not running), the pressure goes up to 40. When I turn the key off, it stays there. Tells me no leaks...
Pulled fuel line loose at fuel filter - turned key on for a couple seconds - gas came out in steady stream.
Hooked a timing light up to two of the spark plug wires - they fired.
Got fire....got fuel pressure.
Anyone have any ideas about what is causing this issue?? I would love some help.

"Some Days It's Just Not Worth Chewing Through The Restraints.."

 

Are the fuel injectors firing?

 

Not sure what you mean - I'm good with mechanical stuff, not so good with electrical. However, the pressure at the fuel rail stays at 40 when the key is off, so the injector(s) should not be leaking. What is keeping the fuel pump running?

"Some Days It's Just Not Worth Chewing Through The Restraints.."

 

In order for the engine to start, fuel has to get into the cylinders. In order for fuel to get into the cylinders, the injectors have to pulse open, which allows the appropriate amount of fuel to get into the cylinders. If the injectors don't "fire" (open), then the engine won't start.

Injectors make an audible "click" when they fire. Can you hear them clicking (a stethoscope would help) while trying to start?

 

The PCM should time out & shut the fuel pump off after 2 seconds. When the PCM is whacked it wont fire the injectors (as mrshorty mentioned) & you wont be able to pull any trouble codes either.

See if you can find an identical PCM at the bone yard.

 

I'm actually on my way to the junkyard in a few - I was planning on picking up a PCM if I can find one. I'll pick up a stethoscope while I'm at it. Injectors can't be pulled at all without removing the upper air intake manifold (that sucks), but I should be able to reach them with a stethoscope..

"Some Days It's Just Not Worth Chewing Through The Restraints.."

 

Well, almost there.
Went to the junk yard and found a 1994 Explorer (mine is a '93) - pulled the PCM out ($28), took it home, plugged it in to my car. Turned the key on - fuel pump came on and went off after about 2-3 seconds!!! Perfect! Started it up. Idles a little rough - little bit of black smoke coming out of the tail pipe - guess it's running a little rich. Check Engine light came on after about 4 seconds. Drove around - got it up to about 50 mph - runs fine, but idles a little rough and CEL stays on. When I turn the car off and restart it, CEL comes back on after a few seconds... So, I am going to check all my vacuum hoses tomorrow and the big plastic air intake 'thing.'

"Some days it's just not worth chewing through the restraints.."

 

Looks like you're making some serious progress. The thing to do now is to pull the trouble codes and see why the CEL is on.

 

Drove it to work today - drives fine other than the rough idle.
I plan on taking it over to Advance or AutoZone today or tomorrow to see what code(s) it's giving..

The 94 I took the PCM out of has an EGR valve - don't think mine has one - could never find anything that even looks close.....Could that be causing the rough idle? If so, how would one go about bypassing that?


"Some days it's just not worth chewing through the restraints.."

 

If yours doesnt have an EGR you'll probably have a permanent code 328 "EGR sensor voltage too low" or some such. I dont know what you can do about that unless you find another PCM thats an exact match for your 93.

You might get lucky & find a parts store that will pull the codes on a 93, but if not you can just buy a Ford scanner at the parts store & pull the codes yourself. Pulling the codes is very simple & the scanner will only cost you about 30 bucks.

The missing EGR should'nt cause your rough idle. Glad to hear it's running so good now. nice job.

 

On a '93 you should be able to pull the codes with a jumper wire (paperclip, short piece of wire, etc.) without buying a $30 tool.

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-Rod