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Re: ECU problems?
[Re: 73ChargerSE]
#209910
01/31/09 10:27 PM
01/31/09 10:27 PM
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Joined: Jun 2008
Posts: 1,822
Colorado
denfireguy
top fuel
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top fuel
Joined: Jun 2008
Posts: 1,822
Colorado
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Quote:
-HOWEVER, I am only getting from 4-5 volts at the coil. I tried 3 different coils, same story.
What could be causing it not to start? Would it be my ECU? Voltage Regulator? Distributor?
Thanks for any help
Paul
With the key in run position, that is the right voltage with the engine not running. In start position with the engine turning over, it should jump to 12V. The voltage should return to 6V with the engine now running.
Take a plug wire off and see if you have any spark while the engine is turning over. If you do not, suspect the ECU or the distributor.
Craig
2014 Ram 1500 Laramie, 73 Cuda
Previous mopars: 62 Valiant, 65 Fury III, 68 Fury III, 72 Satellite, 74 Satellite, 89 Acclaim, 98 Caravan, 2003 Durango
Only previous Non-Mopar: Schwinn Tornado
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Re: ECU problems?
[Re: 73ChargerSE]
#209914
01/31/09 10:46 PM
01/31/09 10:46 PM
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Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
RapidRobert
Circle Track
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Circle Track
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
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(1) take the primary wire off of the coil (-) terminal & w key on tap it to a metal ground & see if the coil secondary wire(held 1/4" from ground) sparks (2) Jump 12V from battery positive post to the upstream side of the ballast & crank it w the key & see if it starts.
live every 24 hour block of time like it's your last day on earth
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Re: ECU problems?
[Re: 73ChargerSE]
#209915
01/31/09 10:57 PM
01/31/09 10:57 PM
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Joined: Jun 2008
Posts: 1,822
Colorado
denfireguy
top fuel
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top fuel
Joined: Jun 2008
Posts: 1,822
Colorado
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Quote:
Ballast resistor was a NOS unit, I tried another ballast resistor (not sure if it was good or not) and that didn't work either. I am not getting any spark at the distributor cap. I thought I should be having about 9 or 10 volts at the coil at the run position.
No spark, ECU or distributor. Probably ECU.
Ballast is out of circuit on switch in start position.
Low voltage on coil is a red herring.
Craig
Last edited by denfireguy; 01/31/09 10:59 PM.
2014 Ram 1500 Laramie, 73 Cuda
Previous mopars: 62 Valiant, 65 Fury III, 68 Fury III, 72 Satellite, 74 Satellite, 89 Acclaim, 98 Caravan, 2003 Durango
Only previous Non-Mopar: Schwinn Tornado
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Re: ECU problems?
[Re: denfireguy]
#209916
01/31/09 11:34 PM
01/31/09 11:34 PM
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Joined: Sep 2005
Posts: 353
Tucson, AZ
73ChargerSE
OP
enthusiast
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OP
enthusiast
Joined: Sep 2005
Posts: 353
Tucson, AZ
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Well I swapped out the ECU for one that was in a running Duster that I've got. No go on that one either. The thing that freaked me out is I realized that when I turn the key off from the start position, the motor reverses it's rotation a small amount and pushes air out of the carburetor. What the heck is going on with my car 
Last edited by 73ChargerSE; 01/31/09 11:38 PM.
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Re: ECU problems?
[Re: RapidRobert]
#209918
02/01/09 10:57 AM
02/01/09 10:57 AM
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Anonymous
Unregistered
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Anonymous
Unregistered
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Quote:
Quote:
when I turn the key off from the start position, the motor reverses it's rotation a small amount and pushes air out of the carburetor.
I've seen that a few times, I just assumed it was from the eng being tired.
No what usually causes that, either key on or off, is that a residual spark occurs, is fed through to a plug, and fires a small amount of "compression" in a cylinder
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Re: ECU problems?
#209919
02/01/09 11:02 AM
02/01/09 11:02 AM
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Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
RapidRobert
Circle Track
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Circle Track
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
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got it, that makes sense.
live every 24 hour block of time like it's your last day on earth
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Re: ECU problems?
[Re: RapidRobert]
#209920
02/01/09 11:26 AM
02/01/09 11:26 AM
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Joined: May 2004
Posts: 1,522
Ste-Sophie, Quebec, Canada
Wedgeman
pro stock
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pro stock
Joined: May 2004
Posts: 1,522
Ste-Sophie, Quebec, Canada
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Hi,
Running from the start, may be you overlooked something obvious ( it is often the case, by experience !)
IF it fires back in in the carb, it means you have spark.......non ?
Voltage is normal,
Ecu is ok...
wires are fine
Is the cap worn or damaged ? if not...
The advance plate moving freely? (not stuck)
Lessen the advance just a notch on the dist to start..(not supposed to turn backwords when turning off)
Did you check the level in the carb ?
Clogged primary jets ?
Have you tried putting gas in the carb and start it? if it does you'll know where to look..
Dan
Last edited by Wedgeman; 02/01/09 11:29 AM.
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Re: ECU problems?
[Re: ThermoQuad]
#209922
02/01/09 02:41 PM
02/01/09 02:41 PM
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Joined: Sep 2005
Posts: 353
Tucson, AZ
73ChargerSE
OP
enthusiast
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OP
enthusiast
Joined: Sep 2005
Posts: 353
Tucson, AZ
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The motor is brand new with new summit double roller timing set. It has less than probably about 50 miles on it. I haven't even had the car on the street enough to get it registered. I'm hoping it's not my timing chain.
Last edited by 73ChargerSE; 02/01/09 02:46 PM.
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Re: ECU problems?
[Re: 73ChargerSE]
#209924
02/02/09 02:54 PM
02/02/09 02:54 PM
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Joined: Jun 2008
Posts: 1,822
Colorado
denfireguy
top fuel
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top fuel
Joined: Jun 2008
Posts: 1,822
Colorado
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Quote:
Well I swapped out the ECU for one that was in a running Duster that I've got. No go on that one either. The thing that freaked me out is I realized that when I turn the key off from the start position, the motor reverses it's rotation a small amount and pushes air out of the carburetor.
What the heck is going on with my car
You did not say if you have a spark yet with the substitute ECU. I forgot to include coil as another possible culprit. To trouble shoot the coil, disconnect the wires going to the negative terminal of the coil. Hook a piece of wire long enough to get to a good ground. Pull the high tension wire that comes from the coil out of the distributor. Place the wire within a half inch of a ground. Take the wire from the negative terminal and tap it to ground. It should develop enough voltage to produce a spark on the coil secondary.
Or take the coil out of the donor car you got the ECU from and swap it out. If the coil is working, and the ECU is known to be good, then the problem is in the pickup in the distributor.
Craig
2014 Ram 1500 Laramie, 73 Cuda
Previous mopars: 62 Valiant, 65 Fury III, 68 Fury III, 72 Satellite, 74 Satellite, 89 Acclaim, 98 Caravan, 2003 Durango
Only previous Non-Mopar: Schwinn Tornado
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Re: ECU problems?
[Re: 73ChargerSE]
#209926
02/02/09 06:48 PM
02/02/09 06:48 PM
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Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
RapidRobert
Circle Track
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Circle Track
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
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you might sub both of the bad items back in there(1 at a time) that way if only 1 was bad(which'd be my guess) you wouldn't be tossing a good part that could go in your glove box as a spare. but maybe after this you dont want to lay eyes on an ecu or a ballast for quite awhile.
live every 24 hour block of time like it's your last day on earth
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Re: ECU problems?
[Re: 73ChargerSE]
#209927
02/02/09 09:31 PM
02/02/09 09:31 PM
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Joined: Jun 2008
Posts: 1,822
Colorado
denfireguy
top fuel
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top fuel
Joined: Jun 2008
Posts: 1,822
Colorado
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I don't know, I think I would leave them both in there and walk very quicly away..... 
2014 Ram 1500 Laramie, 73 Cuda
Previous mopars: 62 Valiant, 65 Fury III, 68 Fury III, 72 Satellite, 74 Satellite, 89 Acclaim, 98 Caravan, 2003 Durango
Only previous Non-Mopar: Schwinn Tornado
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Re: ECU problems?
[Re: 73ChargerSE]
#209928
02/02/09 10:02 PM
02/02/09 10:02 PM
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Joined: Aug 2004
Posts: 1,047
Arizona
68CoronetRT
super stock
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super stock
Joined: Aug 2004
Posts: 1,047
Arizona
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Quote:
Well I put the substitute ECU and put a new ballast resistor on it and it fired right up. So I think both of those were bad.
My money is on the ballast being bad. You said the ECU worked in your Duster right?
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