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Fucking EDIS no spark

arse_sidewards

Contrary to everything
Joined
May 19, 2020
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Vehicle '95 Ranger so no external EDIS module, the coil driver is integrated into the ECU.

Scanner shows a PIP signal. Key On Engine Off test shows only emissions related faults, no misfires or anything related to the ignition system.

I have confirmed the harness wiring for the crank position sensor circuit (would be no PIP without it anyway), the harness wiring for the ignition circuit and that there is an AC signal present on each of the pins corresponding to a coil when cranking.

Coil is from a '00 Taurus instead of a Ranger but I don't think that should matter.

I have played musical coils with three coils (one of which was running this engine before I swapped it out of the Taurus it came in) and three ECUs, same results.
I can smell fuel in the exhaust so it's getting something.

I have confirmed with a spark tester followed by my hand that I am in fact not getting spark on any cylinder.

To make this more confusing, at one point I mashed 2/3 of the coil circuit pins when playing musical ECUs resulting in it running on two cylinders.

The fuck am I missing?

Yes I know I should have just slapped megasquirt on it but that ship has sailed.
 
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What do you mean negative side? Like the ground? What kind of signal should I be looking for?
 
What do you mean negative side? Like the ground? What kind of signal should I be looking for?

There's 4 wires on your coil pack. One is 12v power the other 3 are ground circuits. Are they triggering?

Edit: also, are you getting 12v to the power wire?
 
There's 4 wires on your coil pack. One is 12v power the other 3 are ground circuits. Are they triggering?

Edit: also, are you getting 12v to the power wire?

12v is present on the red wire. No voltage or change between ground and the other three while cranking. No resistance change between ground and the other three while cranking. It's like it's not even trying to fire the coil. I verified continuity between the three coil pins and the corresponding pins on the ECU connector for the millionth time and they're still good.
 
12v is present on the red wire. No voltage or change between ground and the other three while cranking. No resistance change between ground and the other three while cranking. It's like it's not even trying to fire the coil. I verified continuity between the three coil pins and the corresponding pins on the ECU connector for the millionth time and they're still good.

12v in and no voltage on any of the 3 signal switches sounds like a bad relay.
 
Spend 30min digging around for the full fuse box from a formerly running driving Taurus that I knew I had somewhere. Spent 5min playing musical relays. No change.

Here's the screenshots from when I was playing musical ECUs on Saturday. Basically the same codes for emissions stuff I don't have regardless of ECU. One of the ECUs shows a fuel pump code but the pump is clearly running and providing fuel. It cranks around 250rpm. PIP signal looks good.

Screenshot_2020-05-23-11-44-10.png
Screenshot_2020-05-23-12-14-35.png
Screenshot_2020-05-23-11-36-44.png
Screenshot_2020-05-23-11-53-09.png
 
The PIP is only going to signal your injectors. The spark signal comes from the crank position sensor to the ecu. I would test the cps. When cranking the signal from the cps will bounce between .5 and 1v AC. You could also test the injectors if you have an NOID light which will help rule out the ecu.
 
The PIP is only going to signal your injectors. The spark signal comes from the crank position sensor to the ecu. I would test the cps. When cranking the signal from the cps will bounce between .5 and 1v AC. You could also test the injectors if you have an NOID light which will help rule out the ecu.

I thought PIP was used by the ignition system.

I don't see how the crank signal can't be good since I get PIP and RPM which are dependent on the ECU knowing the engine is cranking. I will check it though.

I've played musical ECUs. At least 1/3 has to be good. One of them briefly ran the truck back when I had bent a couple of the coil pins (which also helps rule our crank).
 
At this point I would say its a wiring issue. You've got a lot of wiring related codes so its possible something got messed up.
 
At this point I'd put a scope on the CKP circuit at the PCM connector and crank on it. Make sure you can see the missing tooth in the waveform and that you aren't just getting noise on that circuit when cranking.
 
At this point I would say its a wiring issue. You've got a lot of wiring related codes so its possible something got messed up.

No shit sherlock, I butchered a '94 harness to make a '95 harness and left out the emissions stuff I wasn't planning on using. :laughing: The question is which circuit is the one that's fucked in a way to keep it from starting. None of the emissions stuff should do that.


At this point I'd put a scope on the CKP circuit at the PCM connector and crank on it. Make sure you can see the missing tooth in the waveform and that you aren't just getting noise on that circuit when cranking.

Funny you mention that. I almost bought a scope at the start of this project. Any old antiquated scope I bought of CL should do the trick, right? I don't see why I'd need any modern features to look at a low voltage AC waveform.

You might be right about the noise. I omitted the shielding from the last foot or so when I made that circuit of the harness and I didn't twist the wires like they do with the VSS circuit. I figured that since nobody runs the shielding on the crank sensor for aftermarket EFI it would be fine. It did run once with this configuration so who knows, maybe having 3/3 of the coils plugged in instead of 1/3 is giving it enough noise to cause problems since those circuits run parallel in the harness.

That said if I'm getting noise there wouldn't it prevent the PCM from knowing that the engine is turning which would cause it to not send anything out on the tach pin?
 
Might finally circle back around to this. Any reason this wouldn't be a suitable scope?

https://worcester.craigslist.org/ele/d/clinton-hitachi-650f-oscilloscope-with/7195380390.html
that'd work, but for automotive shit you're much better off with a cheap digital scope for that kind of money

keep in mind that EDIS needs two complete crank revolutions before it'll even start trying to spark
I dunno if you're just seeing no spark and stopping immediately, but something to keep in mind
 
[486 said:
;n132457]
that'd work, but for automotive shit you're much better off with a cheap digital scope for that kind of money

How cheap is cheap? I always thought that the cheap scopes were kinda like the $30 scan tools that call themselves a scan tool but can't actually do much.

Edit: Here's three cheap Chinese ones. Other than more effectively take up shelf space, what will the $100 analog scope do that the $30-$75 Chinese ones won't.

https://www.ebay.com/itm/New-Full-A...pe-2-4-inch-LCD-Display-Handheld/333699591189

https://www.ebay.com/itm/Digital-St...ter-DMM-AC-DC-Voltage-Meter-P8J6/303586707344

https://www.ebay.com/itm/Handheld-D...-DSO-2-4-100MHz-500MS-s-ADS5012H/133503327602


[486 said:
;n132457]keep in mind that EDIS needs two complete crank revolutions before it'll even start trying to spark
I dunno if you're just seeing no spark and stopping immediately, but something to keep in mind

Oh I'm letting it crank alright. :laughing:


Ford people are so sensitive about cheap, easy, and reliable .:flipoff2:

And Chevy people are the ones smart enough to think that swapping an engine to solve an electronics issue is cheap.
 
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How cheap is cheap? I always thought that the cheap scopes were kinda like the $30 scan tools that call themselves a scan tool but can't actually do much.

Edit: Here's three cheap Chinese ones. Other than more effectively take up shelf space, what will the $100 analog scope do that the $30-$75 Chinese ones won't.
what it will do that those linked won't:
2 channel operation, two traces at once on screen
look like something outta an old sci-fi tv show

basically every other aspect you're better off with the digital shit
 
Have you verified all your circuits,

Several times over for every ignition system component.

When I built the harness I printed out the two pin-outs, made a color coded diagram and then stuck the '95 ECU plug on the '94 narness and then added the missing circuits using the correct color wiring out of a Taurus.

The only alteration I made is that I tied all the grounds together and ran a fat one to the body rather than running them individually to the body and I omitted the downstream O2 wiring.
 
So I finally got around to working on this. On the advice of someone on Ford Six Performance I re-did the crank sensor part of the wiring harness to use twisted wire and include a grounded shield. The shield runs from within an inch of the ECU plug to within about two inches of the crank sensor. Signal came out looking no better or worse than before. Per Forscan the ECU is clearly aware that the engine is turning over. At this point I'm gonna try a new crank sensor and if that doesn't do it I'm gonna try fucking around with the coil pack wiring.

IMG_20201222_104808_697.jpg
IMG_20201222_110555_486.jpg
Screenshot_2020-12-22-11-57-06.png
 
Anyone with an EDIS Ford and Forscan want to do me a favor and unplug your coil pack and crank the engine and take a snapshot of the PIP so I can see if mine's different?
 
Worth noting I verified all my grounds with an ohm meter. Is there anything beyond that I can do to ensure the coil is grounding properly?
 
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