Bad ECU from the factory!!?

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Already checked those wires both with key on, and off, and verified that they are wired accordinding to diagram/instructions. Plug to ECU is only a year or so old, all wires are like brand new. If ECUs turn out to be OK; I will probably go after HEI distributor next.
 
Dig this! I just got back from Advance Auto Parts. I had the ECUs tested. They were all bad! Tested one off of the shelf. It passed! I bought it, and am about to install it. In conclusion: I received 2 ECUs in two days new in box direct from Summit, and both were junk, and cost $4 more each (not including shipping). Hopefully now I can put my hood back on, and tear up some pavement!
 
Thats odd that they are all bad.

What's not to say that the reason that they are bad is because something is faulty in your car and causing them to go bad?

or were one of more of them not hooked up to your car at any point in time?

Not doubting you, just thought of that and figured I would mention it.

If that was the problem .....then you my friend stumbled across some harsh odds LOL and good luck on getting it running.....do some sweet burnouts!
 
Exactly what I was thinking. So I tried the box. Car still does not start. Took box back to Advance Auto Parts to recheck. Box is still good. Now that is isolated as not the problem.

Can the coil still be bad despite passing primary, and secondary resistance test? What other checks can I do to the coil, distributor exc.?
I'm going to go grab a beer, and think about this one.
 
If it were me....I would run through it all (soundsl iek you have done most of it anyhow)....I would check all fuses,all grounds,power connections on back of gauge cluster,relays,all the pins on the interior side and engine bay side of the firewall harness plug in,I would check the resistance of any wires i could get ahold of from the starting point of the wire all the way to the ending point so I could see if there is a bad spot in the wire.

also there is the factory fusable links that I am not a fan on on any car...some times they will burn out or the tiny stranded wire inside falls apart/burn and you can feel the wire and it will feel spongy and you can sometimes stretch the wire and tell its junk ( I replaced mine with a 20 amp inline fuse) (you should have one at the engine bay side of the bulk head connector.....a red wire i believe with a black plastic rectangle looking type of thing surrounding part of the wire) .

I would check power to coil,I would check all wire at the regulator/ecu.

You said you switched to a points set up and got a little stumble out of it so maybe somewhere in the wiring tied to the distributor by chance?

I had trouble getting no spark on my engine in my duster with points set up and it turned out being a bad connection at my coil.

if you pull your distibutor cap off you should be able to manualy arc a spark with a screw driver at the pick up terminal as long as you have power running through the coil to the distributor and the key on.

if no spark, I would get out a test light, ground your clip somewhere and with the key on check the power lead at the pick up wire in the distributor if you have power to the wire but no spark at the pick up....then you need to replace it (we jsut had to do this on a buddys demon).....if no power from the pick up wire at all with key on or in start position then your problem is somewhere else.....

check all connections for any corrosion ( I dielectric grease all my electrical connections).

it will probably end up being an easy fix (there is only so much wiring to an older car after all).

I hope something I said can help you out...I am just trying to name off things for you to check that maybe you have not already.... Good luck!
 
also, to pin point if your harness is bad or if it is a coil/distributor/pick up problem....

I would run a temporary power lead directly from the positive terminal of the battery to the "power in" side of the coil....that will eliminate any factory harnessed power that may have anything to do with sending power to the coil.

if you still have a no spark issue than you can atleast eliminate all the other factors in the problem........and if you DO get power, then you know that the problem is in your wiring or in one of the components that you wiring connects to prior to the distributor and coil.
 
crabillac said:
Exactly what I was thinking. So I tried the box. Car still does not start. Took box back to Advance Auto Parts to recheck. Box is still good. Now that is isolated as not the problem.

Can the coil still be bad despite passing primary, and secondary resistance test? What other checks can I do to the coil, distributor exc.?
I'm going to go grab a beer, and think about this one.
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OK, you said it will not start now with the new box. Did you check to see if at least you are getting spark? The distributor could be off timing and make it not start!
 
Tomorrow I am going to go over everything, and I am going to keep a log of everything I do from start to finish. If the thing does not start after all of my efforts; I will post the log, and maybe someone can point out what I do wrong, or don't do, or anything. I really appreciate all of the advice/info etc. We will eventually get this baby lit. I just had to step back, and take a day off today.
 
you said it ran before you adjusted rocker arms is possible they are to tight causing other issues ? lack of compression on some or all cylinders?
 
Possible,but I don't think so. When it turns over it seems normal. And when I said adjusted the rocker arms; I was embarrassed to admit that when I put the rocker assembly back together; I had the lefts on the right, and the rights on the left, but only on one side. I then torqued the assembly back down (after rearanging the rockers) in the proper sequence according to the book. I am getting ready for tomorrow. I pulled the #1 plug, and hooked up my compression gauge. I used a jumper wire to use the solenoid on the firewall to bump the engine around to top of compression on #1 cylinder. I pop off the distributor cap, and look at the rotor position. I reset the compression gauge, and try two more times. Rotor is in same position all three times. I pull distributor and bring in house because mosquitoes are eating me alive. Tomorrow will inspect, and reset reluctor if necessary.
 
Yes compression and how you have you valve train set up and what you have your timing at will make a difference in how/if it will run..... But that's not your problem, you have a no spark issue/no power to your components that make spark, which has nothing to do with the other stuff.
 
OK First check coil resistances. Primary is between 1.3-1.8 secondary is 1.998. Blue wire from ballast to + side 12V. blue ignition wire hooked to + side 12V. Black tach ground, and black and yellow wires to - side of coil. To be extra careful; after everything that has to do with removing wires or connections; I unhook the battery.
Installed ECU made sure of proper ground. Took ground to pin measurements just to see if I got anything besides the reading off of the ground pin. On the #1 pin I got .63-.66 in ohms scale. I am not sure if this reading even means anything.
Installed dual ballast resistor, but only using two connections for now.
Inspecting distributor. Reluctor may be a little tight on a .010 brass feeler, but feels pretty good.Hooked up using plug. Pulled all wires off of cap, and rewire with rotor pointing at #1, and continue 1-8-4-3-6-5-7-2 in clockwise direction wires are same as before. turn on key turns over but no fire.
I try to arc the pick-up as well as get meter readings with key on but get nothing from pick-up. I notice that the ECU umbilical is not a perfect fit over the ECU fitting, but I do believe that the contacts are making contact. I ran a 12v wire from battery directly to the + side of the coil, and get no spark, but it does light up the parking "Brake" light on my dash with the key off. Now what?
 
crabillac said:
OK First check coil resistances. Primary is between 1.3-1.8 secondary is 1.998. Blue wire from ballast to + side 12V. blue ignition wire hooked to + side 12V. Black tach ground, and black and yellow wires to - side of coil. To be extra careful; after everything that has to do with removing wires or connections; I unhook the battery.
Installed ECU made sure of proper ground. Took ground to pin measurements just to see if I got anything besides the reading off of the ground pin. On the #1 pin I got .63-.66 in ohms scale. I am not sure if this reading even means anything.
Installed dual ballast resistor, but only using two connections for now.
Inspecting distributor. Reluctor may be a little tight on a .010 brass feeler, but feels pretty good.Hooked up using plug. Pulled all wires off of cap, and rewire with rotor pointing at #1, and continue 1-8-4-3-6-5-7-2 in clockwise direction wires are same as before. turn on key turns over but no fire.
I try to arc the pick-up as well as get meter readings with key on but get nothing from pick-up. I notice that the ECU umbilical is not a perfect fit over the ECU fitting, but I do believe that the contacts are making contact. I ran a 12v wire from battery directly to the + side of the coil, and get no spark, but it does light up the parking "Brake" light on my dash with the key off. Now what?
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OK, you say you just replaced this motor and now can't get it to fire and run? Where are you located? Close members to you? If I were you here is what I would do: find a mopar friend that had a old small block points distributor or hit the junk yard or craigslist and get a used one (just to get the engine running and make sure everything else is OK with this points distributor! That way everything else is eliminated, you know the engine runs great and then you step back and figure out the electronic ignition end of things. I have had to do this before just to get an engine running.

Did you notice the fuel gauge come up (start working) when you had the jumper wire on it? I'm going to guess here you were back feeding the wiring circuit that would have been activated when you turn the key on. In otherwords, you were giving 12 volts the the same wires with your jumper that would have got 12 volts when you turned on the key.
 
I have a points type distributor that I can put back in. Do I go back to stock coil? What about the voltage regulator? What are the symptoms if it is not functioning properly? I have a solid state aftermarket replacement in the car at this time. The car turns over but does not start. It does not seem to be getting spark to the distributor pick-up. When you give it 12v the brake light on the dash lights up because the brake is on. It lights up with the key off. My gas gauge never worked since I have owned the car. Everyone I know is a Chevy head, and if you tell them about a problem; they reply "That's cuz its a Mopar" They dislike what they can not understand.
 
Fishthatkills said:
Is the ecu grounded really good? What diagram did you use to connect it up ?


John B.
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Last summer we had a '70 Duster come into the shop. The owner painted the engine bay and installed a new ecu and was never able to start his car after that. The problem was that the box wasn't getting a ground. Scraped paint behind box and it fired right up! All in the ground. Of course you may have another issue. I just thought I would toss this out there for others that paint their engine bay.
 
Changed back over to original distributor. Came in to check thread before attempting to start. Did not yet switch from "hot coil" to original. Eliminating ECU for now.
 
Did not fire. Gave coil 12v does not fire. Checking ignition switch next I guess.
 
Dude I am sorry that you are having so much trouble. Those technician induced bugs are the worst. I hope you find the cause and reply back what you find. Did you say it was working before the ignition swap? or has not since you swapped motors?

John B.
 
Added wire from the fuse box got 12V to + side of coil. Remove wire, and nothing. I also have spark from distributor.(found that the electronic distributor was no good not producing spark), I also found a bad wire to the sensor on the intake manifold) So now I have a coil, and a distributor that is working. When I turn the key to start; I get no voltage to coil. When the key is in the ON position, I jump the relay; I get voltage as far as the distributor, but nothing to the plugs. I am guessing bad ignition switch. Especially since it kills the coil in START position. Why no spark to plugs in ON position w/relay not key? Why only voltage with added wire from fuse box? Are these the symptoms of a faulty ignition switch?
 
OK got spark to plugs. Ran 12V directly from battery. Removed 12V from fuse box. Turned over with starter relay on fender. It has got to be the ignition switch. I am going to pull and inspect/clean, and try again later. If no start... I will replace.
 
Switch was good. Traced wires. wire to ballast resistor had a brown wire with a tracer connected to it for no reasonand then tied into resistor wire.Also discovered cracked connector at ampmeter. Turned over w/stock distributor. It fires but doesn't stay running. I decide that as long as the spark problem is over;might as well tie back into ballast w/electronic HEI setup. 1/4 turn of the key, and VRRROOOM!! she fired right up. This mystery has been solved. I will re-wrap all wires back up tomorrow. I thought that putting the driver's side header on was a challenge, but man that was nothi ng compared to this adventure in wiring. I hope that this thread can maybe help some others with similar problems.:-D
 
Awesome!!!! glad you got it figured out buddy.

Gotta love them stupid wiring issues lol
 
crabillac said:
Switch was good. Traced wires. wire to ballast resistor had a brown wire with a tracer connected to it for no reasonand then tied into resistor wire.Also discovered cracked connector at ampmeter. Turned over w/stock distributor. It fires but doesn't stay running. I decide that as long as the spark problem is over;might as well tie back into ballast w/electronic HEI setup. 1/4 turn of the key, and VRRROOOM!! she fired right up. This mystery has been solved. I will re-wrap all wires back up tomorrow. I thought that putting the driver's side header on was a challenge, but man that was nothi ng compared to this adventure in wiring. I hope that this thread can maybe help some others with similar problems.:-D
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Great job! Glad you got it running.
 
With which ECU did it start on? Now swap in the others and see if they really test dead, since this thread is about ECU 's failures and a suppler is named. Thanks
 
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