I have been on this forum a few times already for this problem and I'm just about out of ideas and patience. I started the truck one day and while warming it up, it just shut off like someone unplugged it. And now if just cranks and cranks, with no spark. I already replaced the ignition module, distributor, cap & rotor, coil, and wires. Still no spark. I read other peoples threads and I seen one that said he had a similar problem and it ended up being his started solenoid. Is that possible? Maybe a voltage regulator? Could one of those cause my problem?

 

my 89 was doing that an I replaced the solenoid,tumbler,actuator cam, an ignition switch and nothing so I checked everything and found out it was getting power to the little terminal on the solenoid so I was going to replace the NSS but nah just wired in a good ol' push button and she starts right up might want to try that goodluck man

 

The solenoid's job is to send power to the starter. Since your engine cranks over, I would say that's not the problem. The regulator controls the alternator. It has nothing to do with spark.

I would get a testlight or voltmeter. The first thing I would check is to make sure you have power on the coil + terminal while you are cranking the engine.

If that checks out, I would put the + probe on the negative tach lead of the coil, and put the other lead of the tester on the engine block. as you crank the engine, the testlight should blink.

If it doesn't blink, the first thing I would do is take the dist cap off, and crank the engine to make sure the rotor is turning.

The other thing you haven't replaced yet is the pickup coil inside the dist.

 

With the Ignition Switch in "Run" do you have at least 6 volts on the "Batt" (+) terminal of the Coil and about 12 Volts on the Ignition Module Red wire? While cranking, do you have 8 or more Volts on the Ignition Module White wire?

 

I do have power to the + coil terminal, and when I put my testlight on the tach terminal of the coil and crank, it doesnt flash, it just stays lit. The rotor is turning in the distributor. The whole distributor is new including the pickup coil inside.

 

It doesn't flash, so it's not turning the coil on and off. That's why you have no spark.

We need to get in were Piffery1 was talking about. It's the module's job to turn the coil negative on and off. So make sure the module has power, by checking the red wire going into the module. It should have 12 volts when the engine is cranking. Also, I know it's a new module, but just to be sure, take both modules to autozone and get them to put it on their machine to see if they are good.

Other than this, the only other thing that is going to get you is connections.

Make sure the black wire coming out of the dist is a good ground. This is the ground for the whole system.

Then check the plugs, and ohm out anything that looks suspicous.

 

Try this: 1. Remove the coil wire from the distributor and attach a sparkplug to it, make sure the body of the plug is grounded. 2. Disconnect the Dark Green / Yellow dots wire from the "Tach" (-) terminal of the coil. You can probably do this by rotating the coil wiring harness connector slightly to the side. Make sure the "Batt" terminal remains connected. 3. Unplug the Radio Noise Capacitor (Black wire) connector from the Red / Light Green wire going to the coil "Batt' Terminal. Temporarily jumper the radio noise capacitor black wire to the coil "Tach" (-) terminal. 4. Run a temporary jumper wire from the coil "Tach" (-) terminal to the shank of a well insulated screwdriver. Turn ignition switch to "Run". Alternately touch and remove the screwdriver shank to/from engine block (Ground). Each time you remove the screwdriver from ground you should get a fat spark at the spark plug. This simulates the old points/condenser type system and if you get sparks it indicates the coil, run wiring harness, ignition switch, etc. are ok. Restore everything to normal. If the above test results in sparks then the problem must lie in: 1. Ignition Module. 2. Distributor. 3. Wiring between Ignition Module and Distributor or Ignition Module and coil. Since you've already changed the module and distributor, I'd bet it's a wiring or connector problem. Either an open circuit (broken wire, bad connector pin, etc.) or one or more of the wires are shorted to ground. Wires can be broken underneath their insulation where you can't see, especially adjacent to connector pins. You need an Ohmmeter to test for continuity and shorts. To test for continuity through a pair of mated connector pins, I puncture the wires with sewing straight pins about a half inch back from each connector pin and connect the ohmmeter leads to the sewing pins. Push, pull and wiggle the wires to see if there is any loss of continuity through the connector. OBTW, you might want to take your modules to the Auto Parts Store and have them tested. I've seen brand new electronics items that were bad right out of the box!

 

I had a 351m do that and found it was my ignition live was rotted out and causing a no start condition.

 

hey quintcy....
what do you mean by ignition live?

 

This is a common problem with the Duraspark II ignition. Frequently the wires or wire connector going from the ignition control module (Duraspark) to the distributer go to ground. Check the wires and support the connector so it does not touch anything.

Many times once the engine warms up the connector opens thus causing the engine to stall and not restart until it cools down.

 

my truck is not starting at all...hot or cold. it just cranks and cranks and has no spark. im going to try and do so of the things people in this thread told me to check.

 

what I ment by ignition live was one of the live wires in the wireing harness
right behind the altinators has got a fuseible link in it and this was rotted out.
And so the motor would crank but the distributer would make no spark. so after
geting stranded a couple of times and messing with the wires I came across this
after fixing it my problem vanished. I belive it was a 10 ga brown wire.

 

On the 86 (not sure about the 85) there is an oil pressure switch in the ignition loop. If the durospark ignition is not getting a good feed from the pressure switch then (no spark to start). Just another thing to check. It might be worth looking at that switch and associated wiring.

 

On '83 460's (and, I think, all subsequent carburetored versions with electric fuel pumps) the oil pressure switch only cuts power to the fuel pumps when oil pressure drops below about 4.5 psi. Therefore, switch failure does not affect ignition system.

 

Yes, Piffery1 is correct! I checked the wiring disgrams. I remembered it wrong. Low Oil Pressure cuts the pumps not the ignition.