No Spark After Parts Cannon

[broncc]

Hello everyone.

I have a '94 OHV with EGR that I'm trying to get running. It fuels fine but I have no spark. At the EDIS box I have; power, ground, a good crank position signal verified by scope, and continuity to the coils. Manually grounding a coil causes the engine to burp. There is no signal to the tach (I don't know if thats normal at cranking speed, it is also an '89 gauge cluster that had a distributor so it may not work at all now) and the EDIS makes no attempt to ground the coil. I have tried this with and without the jumper to the ECU installed. I thought the EDIS was bad. I installed a new one from the dealer and it has not solved/changed my issue.

I'm running out of patience and favorable weather. Anyone who can chime in with experience will be appreciated.

 

[Shran]

Is this a 4.0 swap you're working on? I'm assuming you've installed it into your Bronco II hence the gauge cluster?

 

[broncc]

Yeah it is. I have made no modifications to the 4.0L harness from engine to ECU. I did buy the donor car in a non-running state, so I can't tell what was wrong other than the P/O claiming bad starter.

 

[broncc]

I HAVE to be missing something simple. I have the ADK2 hooked up to the brand new EDIS and am supplying it with the ADK's max output of 10v which I think is still is a reasonable voltage during crank.

I can't reasonably see it needing anything more than power and a crank signal to work.
8 - 10v
9 - gnd
6 - cps - wavegen - scope ch2
5 - cps gnd - wavegen - scope ch2
3 - spout - scope ch1
4 - dgnd - scope ch1

Book says that it should look like this:

I think I did a decent job approximating 36 - 1
crank sensor should output 1vpp and and 150hz at cranking speed, I have exceeded this to emulate idle

This is baby's first (second?) OBD1 car and I could really use some help. Anyone here had to fix this before? This is exactly what I saw when I tested it in the car. Did I just get unlucky and end up with two junk EDIS? I'm sure I'm missing something simple...

 

[Shran]

It has to be something simple. I did a 4.0 swap from a 94 Explorer into an 89 Ranger, basically the same thing you're doing, and only had to splice about 8 wires on the driver's side to make it run.

Have you tried a different coil pack? Grounds accounted for in the cab around the ECM? Does the ECM throw any codes? Kinda grasping at straws...

 

[broncc]

I'm not sure whats going on. New EDIS has spark. Maybe the probe on the PIP probe was loose last time? Maybe I poked the spark in instead of out signal last time.

The output is really gross because its at the limit of the poor ADK's power supply. Now to figure out why it doesn't work in the car...

 

[RonD]

Yes the EDIS system is plug and play, many hotrodders used these because they are basically stand alone distributorless spark system, just add load advance

crank sensor(tone wheel), 2 wires to EDIS, 3 if you count the shield
EDIS-6, 12v and ground
3 coil Pack, 3 wires from EDIS and 12volt power
So 7 wires at EDIS-6 for basic opertion

Whole system seen here:

https://imgur.com/4cuB7HX

Doesn't need the PCM(engine computer) to start spark or for RPM advance, just for Load advance

So after re-installation spray fuel into the intake, 50/50 test, that takes the need for PCM off the table

 

[broncc]

Took it off the bench and stuck it in the car.

Interesting how it only has PIP signal for a second of cranking before cutting out. I got home late and didn't want to crank the car all night so I gave up early. I have 11 volts at the fuse while cranking.

 

[RonD]

Looks like crank sensor stops generating AC Volts(readable sine wave)

Crank sensor needs no voltage to work, it generates its own voltage, 0.5vAC to 1.0vAC at cranking speed
So could be the tone wheel/reluctor ring is not spinning true and/or close enough to crank sensor for it to induce voltage to the sensor full time

 

[broncc]

Well I'm convinced my car is haunted.

I fed in a simulated crank position signal into the EDIS from the CPS connector. It had the same behavior as my previous post until I cranked up the amplitude to about 6vpp (EDIT: probed at EDIS connector). Then I could hear the ignition coils whining with matching good PIP signal. I figured I had a weak CPS even though the book disagreed. I installed a new Motorcraft crank sensor and had similar luck. Both the old (OEM) and new sensor have about 3vpp output at cranking speed. I figured maybe the harmonic balancer I bought was made wrong. It has the same diameter of 100mm and the teeth are machined similar enough to eachother. I even took a magnet to both and they were about equally sticky.

I have genuinely no idea what is wrong with this car. It seems every time it tracks spark for two rotations and then quits. If anyone here has any experience with EDIS or early megasquirt stuff or even know a friend, please pass on the contact info.

 

[Shran]

That's super weird... can you/have you ruled out a broken or damaged wire to the crank sensor? Many of them I've seen are in bad shape. Just shooting in the dark here, wires rubbed/melted together, almost broke off, ???

 

[Snoranger]

I know from my SOHC/EEC IV project that at some point they redesigned the crank sensor. It uses the same connector but the + and - are switched. It will not run if they are switched.

 

[broncc]

I know from my SOHC/EEC IV project that at some point they redesigned the crank sensor. It uses the same connector but the + and - are switched. It will not run if they are switched.

This is a good idea. I had depinned the connector when putting the motor back together to put some heat shrink on one of the wires where it was starting to rub through. Maybe I had put it together wrong? I went out and swapped it around. I now have the gray wire closest to the engine block while plugged in. I cranked the motor and had no luck. It still tracks for two engine rotations and quits.

Does anyone with a running OBD1 OHV have a moment to tell me how yours is pinned? Maybe you could take a scope to the car? Is there anyone in driving distance willing to let me poke their car?

 

[holyford86]

This is a good idea. I had depinned the connector when putting the motor back together to put some heat shrink on one of the wires where it was starting to rub through. Maybe I had put it together wrong? I went out and swapped it around. I now have the gray wire closest to the engine block while plugged in. I cranked the motor and had no luck. It still tracks for two engine rotations and quits.

Does anyone with a running OBD1 OHV have a moment to tell me how yours is pinned? Maybe you could take a scope to the car? Is there anyone in driving distance willing to let me poke their car?

depends on your definition of driving distance, if you're still trying to figure it out I can check the pinout when I get home

 

[broncc]

depends on your definition of driving distance, if you're still trying to figure it out I can check the pinout when I get home

I'd really appreciate that. I could mail you both of my EDIS to check if they work too.