'94 F-150 5.0 4X4 NO SPARK!! need pointers plz!

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Old 09-08-2010, 09:23 PM
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'94 F-150 5.0 4X4 NO SPARK!! need pointers plz!

The engine died at a stoplight, restarted it and got about 2 blocks and no more. towed it home, and determined that it had no fire. couldn't get to it for a couple of days, and the battery went dead from the hood being open, and i really screwed up and left the key on. since i'm planning on dropping in a low miles 5.8 soon, i replaced the pickup coil in the distributor, and the ECM while the battery was charging. i ran a self test and came up with code #52, ECT module. i put in a new one, and still NO FIRE! i have good fuel pressure at the schrader valve, juice to the coil, and popped the new one from the 5.8, ran the self test again and get code# 111(clear). i'm totally stumped here and really could use some pointers. what else has control over spark? any help would be most appreciated.
 
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Old 09-09-2010, 11:31 AM
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1) There is no code for ECT; codes indicate faults - not parts. Read the WHOLE code definition; don't just pick out the name of a part.

2) Your EEC uses 3-digit fault codes, so you didn't read it right. Read this caption & the link in it:



3) The ECT isn't a module; it's a small 2-wire sensor screwed into the heater outlet on the intake. What exactly did you replace?

4) "Good" isn't a pressure. How much pressure is there at the fuel rail?

5) Juice at the coil doesn't make it spark - a pulse to ground on the T/Y wire does. Connect a 12V test light between the coil connector terminals & observe it during cranking.

There are several things that could interfere with spark. When you cycle the key from OFF to RUN (not START), do you hear the fuel pump in the selected tank come on for ~1 sec and stop? After cranking, can you hear it do the same thing? If it DOESN'T come on during cranking, the PIP circuit is suspect. If it EVER runs longer than 2 sec when the engine is NOT running, the EEC is probably burned up, but that would be very unusual for a '93-up EEC.

Read this caption:

 
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Old 09-09-2010, 07:01 PM
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Yes,the two wire ECT sensor that screws into the heater outlet in the intake was replaced , 40 LB fuel pressure at the Schrader valve via snap on fuel pressure guage. power to the coil at the terminals and pulsing at crank.fuel pumps cycle 1sec each at key on, and begin to run during crank then quit simultaneous to cranking stop. i may have missed the first digit in the 3 number sequence and used the #52 code for ECT voltage out of range, it was cheap and may be used on the 5.8 if compatible.
 
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Old 09-10-2010, 12:08 PM
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Everything you posted says the ignition system is working (at least up to the coil connector) and the EEC is receiving the signal from it. What happens if you pull the coil wire off the center of the distributor and place it ~1/8" from something metal during cranking? Can you see/hear a spark jumping out?

Getting that whole correct code might help.
 
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Old 09-10-2010, 07:25 PM
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ZIP! i have tried and pre tested a couple of other coil wires, and same thing. i have a zenon bulb spark indicator, and had to check it on another vehicle to ensure that it was working because i couldnt believe that i wasn't getting fire with all of the other indicators. innitially the reason i replaced the coil, is because the coil wire post was rather pitted from 180,000 miles when i replaced the distributor pickup. i've had a couple of other vehicles go belly up in the past, and usually it was either the pickup coil or the control module. due to time constraints, i haven't been back to it for a few days, and guess i will start from square one and bust out the meter and start checking all values and connections to make sure i'm really where i think i am aside from the no spark result. thank you for your feedback. times like this, i really appreciate my old '58 Y block!
 
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Old 09-10-2010, 10:30 PM
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If you have power & ground pulse at the coil, but no spark coming out, then the coil is bad. You said you replaced the pickup (PIP) inside the distributor, but you didn't mention replacing the ignition coil. Test it first, and if it's bad, test the new one before installing it.
 
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Old 09-23-2010, 05:19 PM
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Angry still chasing gremlins!!!!!! 5.0 no spark!!!!

I finally got a chance to get back to the truck, with the haynes manual in tow this time in order to chase things in thier order of priority. in the process of going through what i had before, i found a couple of changes. First, when checking for test light flicker at the tach/ground terminal of the coil, the light is bright, but no flicker this time. it checked out ok for continuity between the terminal and the #2 slot on the control module. i went through all the other checks and everything checks out ok(voltages,resistances, grounds,etc.) the other thing that changed, is that fuel pressure at the schrader valve with key on, is now 95 LBS, not the 40 i had before.i also ran another koeo self test and came up with 121 and 123 codes. i just can't figure this thing out!!!
 

Last edited by horsez2go; 09-23-2010 at 06:37 PM. Reason: added info
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Old 09-27-2010, 04:43 PM
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You're jumping around too much. Follow the ignition diagnostic procedure step-by-step. Don't just start doing all the tests. If it says skip to step 47, do it. If you follow what it says, you'll find the fault.
 
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Old 09-27-2010, 10:51 PM
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Thats whats drivin me nuts....i have followed the rat path to the letter, and everything that i get for values i.e. ohms resistance, voltages and percentages of battery voltage all dictate that i have no problems, other than the no pulse and that the circuit checks ok....3 times. i'm tellin everyone to eat dirt and gonna do it one more time, one step at a time (again). thats the bad thing...everyone has something busted that needs repaired (NOW), and i can't even get enough time to fix my own FAVORITE truck! thanks for the pointers tho....
 


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