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> Sudden Cut-out While Driving, ~faulty relay board was the culprit
poorsche914
post Apr 17 2014, 12:09 PM
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Driving to work this morning and my 2.0 D-jet suddenly cut out. Tach dropped to ZERO. It fired back up fairly quickly being still in gear and rolling. Did this twice.

Made it to work and when I went out to start it, would not fire. Can hear the fuel pump and have fuel.

Ideas where to start looking appreciated.

Some more info that may have impact:
Optima red battery that has a bad cell or something... drains overnight to around 75%. Other than that, cranks strong.

Just replaced the relay board a week or so ago due to intermittent starting issues. Could go for weeks with no issues then turn key and starter would not engage. Rolled it off to start it for a week or so and then suddenly ignition worked fine (IMG:style_emoticons/default/confused24.gif) Finally quit working altogether - couldn't even roll start it.


Thanks,
steve

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dlee6204
post Apr 17 2014, 12:26 PM
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I'd get a spare spark plug see if any of my cylinders were firing... Could be bad wiring, bad coil, connections, and/or bad ignition switch if they aren't.
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poorsche914
post Apr 17 2014, 12:32 PM
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Swapped out relay boards... fires up but the fuel pump isn't running (IMG:style_emoticons/default/dry.gif)
So, at least I have narrowed it down to a bad relay board. I have several... just hope one of them is good (IMG:style_emoticons/default/smile.gif)

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76-914
post Apr 17 2014, 05:06 PM
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Or a bad connection (in the 14 pin plug or engine harness that connects to the relay board) that when moved, disconnects or re-connects itself. Time will tell. (IMG:style_emoticons/default/beerchug.gif)
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Tom
post Apr 17 2014, 06:14 PM
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OK, I am sorry, but did you use any GM parts? (IMG:style_emoticons/default/biggrin.gif)
OK, serious now! It sounds like you have a bad connection on the relay board, either at the 14 pin or 12 pin connectors, fuel pump relay ( good place to look), OR, a bad ignition switch.
The relay can be made to make better contact by slightly spreading the male prongs, this will hopefully eliminate any relay issues and help you search for other issues.
Tom
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poorsche914
post Apr 17 2014, 06:16 PM
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QUOTE(76-914 @ Apr 17 2014, 07:06 PM) *
Or a bad connection (in the 14 pin plug or engine harness that connects to the relay board) that when moved, disconnects or re-connects itself. Time will tell. (IMG:style_emoticons/default/beerchug.gif)

QUOTE(Tom @ Apr 17 2014, 08:14 PM) *
OK, I am sorry, but did you use any GM parts? (IMG:style_emoticons/default/biggrin.gif)
OK, serious now! It sounds like you have a bad connection on the relay board, either at the 14 pin or 12 pin connectors, fuel pump relay ( good place to look), OR, a bad ignition switch.
The relay can be made to make better contact by slightly spreading the male prongs, this will hopefully eliminate any relay issues and help you search for other issues.
Tom

Thanks for the specific pin info, guys... will look into that.
I took one of my boards and started stripping the tar just to take a look at what is there. With any luck I will find some obvious break or corrosion.

Nope, no GM parts (IMG:style_emoticons/default/smile.gif)

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TheCabinetmaker
post Apr 17 2014, 06:23 PM
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Do a continuity check on the harness for the ecu. I had the same problem. Turned out to be a broken wire from the 12 pin.
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TheCabinetmaker
post Apr 17 2014, 06:25 PM
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Mr Anders has the instructions on his site
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poorsche914
post Apr 17 2014, 06:29 PM
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QUOTE(The Cabinetmaker @ Apr 17 2014, 08:25 PM) *
Mr Anders has the instructions on his site

Thanks. I did a quick look there earlier but didn't see anything that jumped out. Will take a closer look.

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Tom
post Apr 18 2014, 02:26 PM
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I read your post again and that draining of the battery grabbed my attention. Are you sure the battery is going bad? With the key OFF, and disconnecting the negative battery connection, do you get any spark at all?
I mentioned removing the negative battery post because it is safer; if the wrench you are using comes into contact with the body when loosening the bolt, it won't cause a big arc like it would if you disconnect the positive battery connector first.
Have you charged the battery fully with it out of the car and then let it set overnight to see how much it goes down? Measure the voltage 1/2 hour after completing the charge, then in the morning and see what the difference is.
Your no start events sounds like a ground issue or bad connection somewhere between the battery positive and the starter solenoid. If you need help going thru that process, let me know and I can help you get thru it.
Tom
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poorsche914
post Apr 18 2014, 02:59 PM
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Battery is a 2+ year old Optima that is going bad (IMG:style_emoticons/default/dry.gif) When disconnected, it drains to around 70-75% overnight.

Pretty sure the issue here is the relay board. I am in the process of stripping all the tar off one and repairing it where needed. After 40 years, loose connections are common on these boards.

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