I have a 94 F250, 5.8L that is in need of a witch doctor or gremlin hunter or something. Here is it's condition:

- Last time I drove it, it was having trouble accelerating until it warmed up, then it started and drove normally.

- It sat for a couple weeks and it's been exceptionally wet here in Washington.

- The battery was dead and after charging it up it will crank but will not even so much as sputter, with or without starting fluid.

- I have spark at the wires (tested 6 of 8), spark at the coil, light flashes when I test for ICM operation and the PIP tests good with an LED light (ie it flashes).

- Fuel pressure at rail is 40 psi after 2-3 on off cycles and steady under cranking. It holds that pressure indefinitely.

- Injectors have power, 12v, tested 2 of 8, both on the drivers side.

- Noid light flashes when plugged into the harness and cranked

- Did a compression test on two of the 8 cylinders and one was 160 psi and the other was 170 psi...

- It was running fine of the fuel in the tank previously but we added 4 gallons of fresh fuel to the gallon or two that was in the tank.

- The distributor has not been moved and is tight. The cap and rotor look good.

- The plugs look a little used and are black but the one we tested had good spark, and one would expect some sort of stumbling, even with very worn/dirty plugs.


So it has fuel, spark, compression and no fire!?!??!?!? I don't get it! I know I didn't test all 8 of everything but it doesn't even sputter or cough...

After all of this the only other clue is that when cranking it will crank fine and then every once in awhile it acts like it's fighting the cranking and slows to a halt for a second and then resumes cranking. If I unplug the ICM it will crank freely and indefinitely...... Any thoughts? Oh and I also replaced the starter in the very beginning as it had a few broken teeth.

 

You have everything else, you must be missing air.........



This is a LONG shot here...pull the connector to the computer (PCM). If it starts then you have bad computer.

 

I thought about this, but even if the PCM was bad, it would cause either a no fuel or no spark condition, correct? I also thought about a timing reference sensor but again, I think you would be missing an element in the combustion triangle. I dont think diesels would differ too much from gas in that regard, but I have been wrong before.

 

better check the timing sounds like a slipped chain

 

I would tend to agree with a bad PCM causing a NO spark condition. On the other hand 1994 was the first year Ford went to COMPUTER controlled ignition systems. But this was only for the dwell aspect as far as I know.

I said it was a long shot.....

 

Can I check the timing while it is not running? I haven't pulled out my timing light in years. Also wouldn't the compression be off if it skipped a tooth?

 

After all of this the only other clue is that when cranking it will crank fine and then every once in awhile it acts like it's fighting the cranking and slows to a halt for a second and then resumes cranking. If I unplug the ICM it will crank freely and indefinitely...... Any thoughts?

this would lead me to suspect the timing, trying to fire before compression is finished as in too far advanced. set engine at top dead center and pull dist. cap and see where rotor is if it isnt 180 degrees out and is not near #1 tower on cap it has jumped time.<!-- / message -->

 

unplugging icm on fender will kill all spark so it isnt trying to fire too soon

 

That sounds doable.. I picked up a coil too in case it's just a weak spark... This will be my first check though.

 

You might try pullling the SPOUT connector to see if it starts then.

The SPOUT is a one pin connector that goes to the ICM. They used somewhat different types for different years. But, it will be a single pin connector leading to the ICM. Disconnecting it brings the system back to base timing. It disconnects the computer from the ignition timing and lets the ICM set it at 10 degrees BTDC.

If it still seems to be firng early you may well have a timing chain or some other timing issue. BTW does the rotor actually turn when you crank it? The gear could have broken.

Good Luck,

hj

 

The rotor spins with cranking, I also checked the coil spark at about a 1" gap and it looked like a stong blue/white spark that was consistent. now I just need to find TDC and check timing

 

Ok, so I tried a few things but still no change. Here is a pic of the only mark I could find on the balancer, it seems to wide to be the timing mark... Also a video of the behavior of the truck...

20121104_101202.mp4

and the "timing mark", which if it is the timing mark then the chain definitely jumped because the rotor is 90 degrees off of cyl 1.

 

ok, so that's not the marking now that I've searched a little. Looks like I need to clean it off and find the real marks... I'm just happy this thing is not my daily driver.... I'm curious what people think of the video... I checked grounds too, I even jumped the batt ground to the engine and chassis to no avail...

 

You have spark, and fuel, how about a bad idle air control valve. If it is bad then there may be no air getting in at idle. Just a guess because you already tried everything else. The simple way to check is just barley open the throttle blades and crank it.

Matt

 

sounds out of time to me per the video