Help with no spark issue

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Sixpack_Sid

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I have a 1975 Duster with a 440 swap engine from a motorhome. I bought an ignition conversion kit and I hooked it up with the original wire harness from the Duster- I think it had a 360 in it-there was no motor when I bought it. I tried starting it for the first time-there is no spark. When I go through my wiring diagram, the wires spread off to other egr and smog features. I have a wiring harness that came with the ECU kit. Can I bypass all of the emissions crap and hook up the wiring harness to the coil and the ballast? The directions show a diagram with one plug ballast resistor on each side, whereas my original ballast has 4 plugs (2 on each side). Can I just go with the 2 plug resistor? The diagram shows one wire goes to "start" and one goes to "run". I'm not sure how to hook up those wires or where they go to. I'm including a PDF of the instructions and diagram for you. Appreciate the help!
 

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You can to a quickie check to see if your electronics is OK simply by jumpering power to the coil and cranking the engine. Make sure that you are getting power in that case to both sides of the ballast

If your harness is not all chopped up, it should be easy. You should be able to connect the new ECU and distributor and go. You should not have needed a kit

Otherwise, the answer depends on how modified/ chopped your harness is

There is only ONE key switched 12V power source that comes out into the engine bay. That one power source provides power, ONLY, repeat ONLY in the run position of the key, for several things under the hood
1....to the ballast and on to the coil
2....to the ECU
3....The blue to the alternator field
4....To the blue on the voltage regulator connector
Most everything else you may not need. Smog doo dads.

You MAY not be getting spark because when the key is in START, the "run" voltage (above) goes DEAD During "start" there are TWO isolated key switch contacts in action. One is the "start" circuit, which involves the start relay and neutral safety switch to activate the start relay, and in turn the starter solenoid

The second is the coil resistor bypass circuit which is INCORRECTLY labled "start" in your aftermarket diagram. THAT circuit in fact is all by itself. That power, also hot ONLY in "start" comes off the IGN2 circuit of the key switch and goes to the coil side of the ballast. That provides the coil hot full battery power during "start" BUT it also BACKFEEDS back through the ballast and feeds power to the ECU during start

In many years, the "run" IGN1 wire is dark blu, the bypass IGN2 is brown. I don't have a 75 diagram handy.
 
Del knows way more about the electronics then i'll ever know, but please tell me it still has the original cam/lifters and not a new one. Nothing worse on a new one then a no start condition.
 
I found a video on how to test the ign module and at the coil everything checks out alright except I'm not getting the Ohms at the pick up cap. It calls for 250-500 Ohms and I'm reading .352 Ohms. It's a brand new distributor. Could the distributor be the problem?
At the coil on the + side when I try starting the car, I read 6 volts. Shouldn't it be higher than that since the battery says 12 volts? The battery is not up to par. What should my voltage be at the coil when cranking over the car? I also have some wires that aren't hooked up-may be emissions crap. Is there a bypass circuit wire that would deliver 12 volts to the coil at the start position? If so, where would that be? Please see pics and if I'm missing something that should be hooked up, can you guys let me know? Thanks!

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If you are SURE about the pickup coil reading, I'd replace the pickup. The ohms stated varies. I would guess the variance is due to loose specs and import parts. But that far off is WAY off.

Don't know what all you have tested, here are a few:
VERY important that the ECU is GROUNDED and that you determine that, with key in "run" that the coil is drawing current. To do that do this:

Turn key to "run." Stab one probe of your multimeter, on DC volts into the top of the NEG batt post or a KNOWN good ground. Stab the other probe HARD into the case/ mounting flange of the ECU box. MAKE CERTAIN you are NOT touching the heat sink/ transistor. With key in run, your should read near 0 or 0

Again with multimeter grounded, connect the other probe to coil MINUS. Reading should be quite low, 1 or 2 volts.

Next connect to coil POSitive. REading should be (variable) 4-7V or so. If it is much lower you have a problem, and if it is full battery voltage the coil is not drawing current

Now with the key in "run" "rig" a spark test gap with the coil wire. Best to use a wire core wire. Take the engine harness half of the distributor connector and tap the exposed terminal to ground. Each time you do so should result in a snappy "SNAP" spark, just one

You can test the distributor "sort of." Connect your multimeter in low AC -- that's right -- AC volts to the connector. Crank the engine or if out of the car spin the dist. shaft. The pickup should generate about 1V AC

Make sure to "work" all connectors in/ out to feel for tightness and to scrub off corrosion. Inspect them with a light, and while you are at it, also take a run at the VR connector. The distributor connector is especially vulnerable as it has no real current flow.

If you can round up a .177 rifle cleaning brush--brass or stainless, they work for cleaning the VR connector, the dist and ECU connector and the flat trailer connector female terminals.
 

Hey guys, thanks for all the advice. I had my old distributor so thought what the hell I will try my old one. It started right up! Again thanks for all the advice.

Syd
 
Thanks for the update. Having a few spare parts is always handy
 
Maybe the dist giving the problem did not have the correct air gap for the reluctor, 0.006-8".
 
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