Ignition Troubleshooting

[mrsnicks]

Okay, so I'm troubleshooting 2 dead cylinders. Here's what I have and what I've done.

Started out with a Rebuilt 318 engine, Rebuilt distributor, new cap, new rotor, new plugs, new plug wires and a new pertronix Ignitor 1381a points eliminator kit. I set the timing correctly by putting it @ tdc and using where the rotor was pointing to start that @ #1 and followed the firing order on the intake. It fired up and ran, but had a miss.


Put in a 2nd set of spark plugs, still has a miss.

2nd set of new cap + rotor. still has a miss.

Narrowed down the problem to the #1 and #8 cylinder. Replaced each of those wires with a new wire. still no spark.

@ this point I"m thinking it has to be the pertronix module? Possibly the little strip of magnetic tape? If it was the #1 and #6 which would be 180 apart I might think I had the timing 180 off, but the #1 and #8 are right next to each other on the cap in the firing order.


Suggestions?

 

[Gpuller]

Hmmm...How new is the rebuild. Possible wiped out cam? I'd pull the valve covers off and see if all the valves are moving like they should. Or if you have a compression tester throw it on those 2 cylinders and see what kind of pressure you have. Just throwing out ideas.

 

[mrsnicks]

Oh.. forget that part.... Did a compression test on all cylinders and they were 120psi +/- 1-2. And when I say dead cylinder I mean no spark @ the cap.

 

[eric383]

Did the rebuilt dist. come with points and condenser? If so, swap those for the pertronix.

 

[dpstark2]

I've had issues with Pertronix before. Check your pickup gap and make sure it's correct and even all the way around. Sounds like the reluctor might be out of round or the shaft wobbling.

 

[Pops1967GTX]

start with the basics. You say it has good compression. Make a check list & start eliminating.....LA 318 Firing Order 1-8-4-3-6-5-7-2. clockwise rotation.... From a buddy who has installed a pertronix unit , make sure the control module is well grounded ........check magnet ring that goes on the distributor cam could be defective. Check by rotate the magnet ring to a different possition, then a different cylinder won't fire?

 

[bigmanjbmopar]

It doesn't make sense that the module is bad if you get spark to the other plugs, have you pulled each wire off and stuck piece of copper wire in the plug end and watched it shoot to ground to see if it's the wire or cap? have you looked at the rotor and hand turned it in the cap to make sure all points hit? It could be the connector built into the cap is broken or bad, try another capo from a different brand. If no spar at the end of the plug wire then you know you can work back from there first cap then rotor then module.


I use bolts shove one in the wire end making sure it makes contact with the wire cif connector. then hold it over the block or metal and crank the motor see if it shoots a spark. if not meter the wire to make sure you have continuity should have ohms depending on your brand of wire could be 100 ohms or more or less. If so, check cap, meter inside of the cap & outside of cap should have 0 ohms or like a direct short. if good then make sure rotor makes contact with those same points, you can test this by holding the rotor inside the cap and meter the back side of the rotor and the other side of the cap should have 0 ohms. if so then I would suspect the voltage getting form the output module to the dizzy it's too low or somthing is causing it to have too low of a resistance. you are not using the ballast right?

 

[vin_vl29u]

I'd put the points back in, see what happens