Car threw P0320, then died, now it will crank but will not spark.
12v at the coils, CKP and CMP voltage detected at the PCM, but the PCM will not fire the coils for whatever reason. I've been stuck on this for some time and I have no idea. I have two PCMs, one original and one known good one, that both yield the same results. I have an entire array of AllData wiring diagrams and I'm still lost.
#1996 Mustang GT No Spark Issue
terse lodge
vestal turret
Ah yes nodata, anyway how's the cam and crank sensor?
Oh ffs again, ignore me
Check the alternator
pure ocean
Got a way to read live data? Or chart the signal from your CPS and CKS? Voltage is good but it one of them is reading flat the computer may not even attempt to start the car. Additionally it’s possible some trouble codes can provide a better clue where to look
terse lodge
I have a shitty scanner to read PIDs, it gets really good crank signal, not that I needed data graphs for that as the tach moves when cranking. My only concern would be CMP signal, because it doesn't output the 5.0v I keep seeing everyone say it should, and I can't see the PID on my scanner
I'm starting to think maybe it jumped time? But if it jumped time, wouldn't it still get cam signal? And furthermore, aren't two valve modulars interference engines? It turns over beautifully with no resistance.
Also one last thing as I'm just talking to myself here, from what I've read and from what I know, if I disconnect the CMP sensor, the PCM should just use stand in data to run the car, which I've tried, and that had no effect on the situation. Same thing for MAF.
pure ocean
Ah - perfect, you have likely already found your issue. If you aren’t getting 5v from your CMP, that’s your suspect. I get that in theory the PCM should use dummy data, but in practice I wouldn’t bet a diagnosis on that.
terse lodge
Well CMP sensor is brand new, maybe cam damage? Or a short to ground on the way to the PCM?
pure ocean
Voltage is lower than expected? Maybe a resistance test is in order - or yeah, a short.
Wait, may be an easier test, do you get 5v output at the sensor
terse lodge
Oh shit yeah that is actually a good test, I'll go out there again and try it this Saturday morning. Only problem is the power steering pump reservoir is right in the way and getting my leads on it might suck
I'll let you know what happens. For further info, when this initially happened, I had just gotten it on the road and clutch in for third when it stalled out, then it fired back up but started idling very very rough and rich, tons of back fire, then eventually just quit entirely, so short to ground could make sense as it progressed more and more until now it just quit
pure ocean
Oooooh - now I see why you wondered about jumped timing. But even then you would still get cam signal. Fun mystery here, I’m excited to see what you discover
terse lodge
Yeah I've been at this for a hot minute, I'll be back with results in a day or two
terse lodge
Well it took me longger than expected, but I was able to get a max of .1v at the sensor
steep orbitBOT
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terse lodge
I looked inside and the camgear is fine, I have no clue why the sensor isn't out putting the .5v to 5.0v it's supposed to,
I'm supposed to be in AC voltage correct? The sensor is brand new so I'm lost on why it'sa not working
terse lodge
I checked both but didn't record what I got, I remember it being low though, I'll try again today.
pure ocean
Cool! Good luck
terse lodge
So, real quick, if it's a two wire magnetic sensor, I'm still checking in DC?
Despite it generating it's own voltage?
pure ocean
Oh holdup, I thought this was a 3 wire. I’m gonna look online and see if I can find a good guide for 2 wire
https://mphdiary.com/how-to-test-2-wire-camshaft-position-sensor/ the folks at “mphdiary” seem to think DC
terse lodge
These are some good tests, I'll try these tomorrow, thank you!
terse lodge
Well, the tests are pretty conclusive that either the PCM is shot, or the wiring harness is. Looks like I'm off to shop for a new engine harness
terse lodge
I've ordered a used harness off of Ebay, but to just ease my curiosity on the functionality of the sensor, how does the two wire CMP sensor work? Does the ECU supply the sensor with voltage? If so then yes, this is definitely the issue.