Dead Ignition system

Tiny
JEFFREYDJUDSON
  • MEMBER
  • 1997 PLYMOUTH NEON
  • 13,000 MILES
Engine light came on, code was upstream O2, which I replaced, and installed a cold air intake while I was into it. Car ran fine but died in it's tracks a short time later. Bad crank sensor, which I replaced, I installed a header while I was into it. Started engine and it ran about 10 seconds, and I shut it off to finish re-assembly and tried to start it later. Nothing. I thought I may have ruined the downstream O2 while installing the header, which I replaced; still nothing. Dead ignition system. No code. What's up with this?

Thanks in advance. :)

Jeffrey
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Friday, September 30th, 2011 AT 7:08 PM

16 Replies

Tiny
JEFFREYDJUDSON
  • MEMBER
Forgot to mention that this is the D4RE (420A) twin cam engine.
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Friday, September 30th, 2011 AT 7:13 PM
Tiny
RIVERMIKERAT
  • MEMBER
Got spark? Fuel? You may have inadvertently disconnected a connector somewhere. Check all fuses and relays. Make sure the fuel pump system is being energized.
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Friday, September 30th, 2011 AT 7:34 PM
Tiny
HMAC300
  • EXPERT
Check your cam sensor for ohms, as they may behigh and not working right and check your automatic shutdown relay in the power dist. Box underhood. That may be bad.
Also check the crank sensor for resistance
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Friday, September 30th, 2011 AT 7:37 PM
Tiny
JEFFREYDJUDSON
  • MEMBER
I've got all kinds of fuel, no spark. The crank sensor is new (Wells), so it should be good, unless it was defective from the factory, but it did run when I started it to see that everything was okay.

Will check the cam sensor and reply as to my progress.

Thanks guys. :)

Jeffrey
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Friday, September 30th, 2011 AT 8:55 PM
Tiny
RIVERMIKERAT
  • MEMBER
Let us know what you find out.
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Friday, September 30th, 2011 AT 10:13 PM
Tiny
RIVERMIKERAT
  • MEMBER
Don't forget to check fuses and relays, as well.
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Friday, September 30th, 2011 AT 10:19 PM
Tiny
JEFFREYDJUDSON
  • MEMBER
. Okay. Now I've got another question; Everything seems to be good, so I checked the Cam Position Sensor, and I got a constant 5 volts "on" signal, with no 0.3 volts "off" signal.

When the 'CMP' goes bad, does it register like this, or is a constant "off" signal? (Or, it simply depends on how the sensor goes, and it could go out either way; mine is just constantly "on"?)

Thanks in advance. :)

Jeffrey
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Monday, October 24th, 2011 AT 9:53 PM
Tiny
RIVERMIKERAT
  • MEMBER
Anything new to tell us? Has your issue been resolved?
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Tuesday, October 25th, 2011 AT 4:29 AM
Tiny
JEFFREYDJUDSON
  • MEMBER
. Update.

Okay, I finally gave up on it and took it to a friend that has another shop (I just run a head shop). He put in on his Snap-On Verus machine, and found nothing. No ignition pulse, no fuel injector pulse. Nothing. His son has a '98, and Frank put his computer on my car, and it started running. Badly at 1st, but it straightened out and ran well. AHA! Bad computer! He put my computer back in my car, and it ran fine for about 30 minutes, then died just like it did the 1st time; no hiss, no spit, no stumble; just suddenly dead. So I changed the computer. Nothing.

I've run a head shop for 32 years, and I work with muscle car era cars, so I like to think I know the game pretty well, and Frank has been in the business for almost 40 years, and he keeps up on the latest technology, and between the 2 of us, we can't crack what's wrong with my little Neon

Any ideas, anyone?

Thanks in advance!

Jeffrey
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Friday, December 16th, 2011 AT 3:38 AM
Tiny
JEFFREYDJUDSON
  • MEMBER
. Oh. I should also say that I did replace the Cam sensor. To date the Crank sensor, Cam sensor, both O2 sensors, the battery, and the computer are all new.

While the car hasn't run, I've put a header, and cold air intake on it, but this will have nothing to do with it's not running.

Thanks again!

Jeffrey
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Friday, December 16th, 2011 AT 3:43 AM
Tiny
RIVERMIKERAT
  • MEMBER
It's a Neon. Not a Charger, Daytona, Challenger, or 'Cuda. THAT is the problem. :D

Did you try the "new" computer on your friend's working vehicle? It doesn't happen often, but buying a defective new unit isn't unheard of.
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Friday, December 16th, 2011 AT 4:32 AM
Tiny
JEFFREYDJUDSON
  • MEMBER
Yes, we did try that. Justin's car ran fine with my computer. That would have been too easy a fix. :(

LOL about the 'Cuda! If it was a 426 or 440, I'd know a lot more about it. :)
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Friday, December 16th, 2011 AT 4:37 AM
Tiny
RIVERMIKERAT
  • MEMBER
Exactly. As I like to say, there are three things to check for on a REAL car: Suck, bang, blow. End of statement. I really miss my 65 Charger and 69 Camaro.

That's a head scratcher, big time. The computer from the other car allowed yours to run fine. New computer works in his, but not yours. How long did you try cranking it over? And same symptoms? No spark, no injector pulses? Voltage to cam and crank sensors? Circuit interrupts at those sensors happening properly? Coil getting power?

Have you checked fuel injection and ignition fuses and relays?
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Friday, December 16th, 2011 AT 4:55 AM
Tiny
HMAC300
  • EXPERT
Just reading what you've done i'd have to say this is a power issue or a grounding probem. Especially if you can put another one in and it runs fine. And yours was put in another car and it ran fine as well. Also in the opwer distribution cneter there is an automatic shutdown relay and that may be closing down then not reopening causing this. There is a black and tan wire that goes to ground on the left dside of radiator, that may be corroded as well. That is the main ground for the pcm. But also check your other grounds, bat to bod, bat to eng, etc.
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Friday, December 16th, 2011 AT 4:39 PM
Tiny
JEFFREYDJUDSON
  • MEMBER
. Update.

Sorry it took so long. I have switched all the relays around in the PDC, and nothing changed.

I looked at the black & tan wire, and it seems to be okay. I am completely convinced that I'm looking for a hidden "insignificant" wire that has shorted or otherwise is intermittent that leads into the PCM.

The black & tan wire was a good guess; I think I'm on the right track; I just haven't found the right wire yet.

Thanks again, everyone!

Jeffrey
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Friday, February 17th, 2012 AT 2:16 AM
Tiny
RIVERMIKERAT
  • MEMBER
Hey Jeffrey, did you just look at that black and tan wire, or did you measure it's resistance with a meter?
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Friday, February 17th, 2012 AT 5:32 AM

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