1994 E150 5.0 no start.

[Eddo Rogue]

fuel pump finally shit the bed?

 

[MISWFL]

fuel pump finally shit the bed?

That was my first thought, so I tried starting fluid. Still won't run and by checking with a test light, I found no power to the coil. I'm going to hot wire the coil and see what happens.

 

[MISWFL]

I jumped the + side of the coil to the + of the battery and nothing changed.

Since the ICM is getting hot on the red/green wire when the ignition switch is on and while cranking, and jumping the coil doesn't change anything, can I safely assume the wiring is good? Does the pickup coil in the distributor send a signal to the ICM and/or PCM when cranking to then send power to the coil? If that's the case, it looks like my problem is a bad pickup coil. I'm planning on ordering some parts from RA and just want to be sure that I've done what testing I can easily do before ordering parts. Here's what I was thinking of buying:

1) Rebuilt PCM
2) Ignition switch
3) Coil
4) Distributor pickup coil/CPS
5) Relays

I should be able to test the distributor pickup coil on the vehicle with a meter. Measure the resistance both stationary and during cranking.

 

[RonD]

The coil gets 12volt with key on
The ICM also gets 12v with key on
The ICM powers the 12v Hall Effect sensor in the distributor(but not the coil)

Hall effect sensor produces a 12v on/off pulse as "vanes" in the distributor shaft spin passed it, that pulse goes to ICM
ICM then pulse the Coil's - wire to unGround and ground it, which causes it to spark, based on the timing pulses from Hall Effect sensor
These timing pulse are also sent to the PCM from the ICM, not directly from distributor
PCM will turn off the CEL when it "sees" valid timing pulses from ICM

Unhook your coil's wires
Key on
With key on you should see 12v on one wire and GROUND on the other, the ground is important, thats from the ICM
Ground is the default state of ICM for its coil - wire, so coil can "power up"


An ignition coil is a pretty simple device
It has a Primary "Coil" which is what it sounds like, just a coil of wire but wrapped around a metal tube
When the Primary coil has 12v and a ground then voltage/current can circulate thru the coil of wire and that makes the metal tube an electro-magnet so creates a Magnetic Field around it
In the center of the metal tube is another coil of wire, the Secondary coil
The Magnetic Field in the Primary coil causes the Secondary Coil to build up a "charge"
Easy version
If Primary Coil has 100 windings/loops around the metal core
And Secondary has 10,000 windings
The 12v will become a 12,000volt charge, low amps but high volts

To release the 12,000v charge you simply disconnect the 12volts from Primary Coil and Magnetic Field goes away and the "charge" is released, you have a spark
You can cut the Coils + or - connection and get a spark, but the - side is usually used
Back in the "old days" we used Points in a distributor, it was hooked to the Coil's - terminal, just safer to use ground side
Distributor shaft has a cam with lobes match cylinder number, i.e. 6 lobes for V6
The points would open and cut coil's - connection when lobe push it open, then reconnect coil's - between lobes to generate another 12,000v spark in Secondary coil

You can test any ignition coil by powering it up and then disconnecting the power, it will spark if its working

Electronic ignitions replaced the points, which always wore out and needed to be adjusted(so bad old days really)
They use a sensor in the distributor that had no contact with spinning distributor shaft, so wouldn't wear out or need adjusting, it read vanes, 6 vanes for a V6
And a electronic module the would cut the coil's - terminal same as Points did, and reconnect it in between sparks
Start of the good old days, lol

 

[MISWFL]

Let's see if I understand it correctly, the ICM should have 12 volts coming into it via the red/green wire, with the ignition on and during cranking? The ICM is also supposed to send power to the pick up coil in the distributor, when the ignition is on and while cranking? The ICM also sends hot or ground signals to the PCM in addition to sending ground signals to the coil?

I'm assuming that I can't use a non computer safe test light to check if the ICM is grounding the coil?

It seems like my ICM ( brand new Motorcraft with correct heat paste ) isn't working right, as I can't see any other power coming from it.

 

[MISWFL]

I ended up ordering a Cardone lifetime warranty distributor, because you have to totally disassemble the distributor to replace the pick up coil. I also bought a cheap coil. Replaced the distributor and the van fired right up. Thanks everyone for the help.

I do have one related question. I noticed the 3 relays mounted next to the coil. They have thick wires on the bottom that go around the back of the engine to the passenger side along side the valve cover towards the front of the engine. Can't easily see where they go. The front relay with the round top is unplugged. Any idea what it does?