3 requirements for proper ignition (140)

[salty3rd]

Re: 3 requirements for proper ignition (140)

I have 2 470's which are 4 cylinder engines, and I just went through the same problems. 4.5 volts on the coil is what I have on both of my engines and they run fine. My problem was that the timing was off almost 90 degrees. The points that were on there must have sat in a different position than the electronic sensor. You can get an idea by putting the timing line at the timing marks on the engine; and that should be the firing position of the #1 cylinder. Then pull the distributer cap off and see if the rotor is lined up to the #1 pickup on the distributer cap. It worked for me. Good luck

 

[nola mike]

Re: 3 requirements for proper ignition (140)

Kind of weird.
1. Timing isn't your issue. Even if it's off, you should get spark to all 4, just not at the right time. Same thing if it was a firing order issue. All 4 plugs should still spark
2. Your voltage at the coil with ignition on is fine
3. Check your voltage at the coil while cranking--should be 12v
4. Why not check to see if you're getting the proper spark off the coil? I mean, it should be 4x the rate of what you're getting at the plugs, which should be easy to eyeball
5. Might be easier to troubleshoot with the points on. You can at least see if the pts are closing and opening 4x/revolution

 

[SSTKO81]

Re: 3 requirements for proper ignition (140)

well the spark I'm getting from the coil is very rythmic. "Spark" 1.2.3. "spark" 1.2.3. ETC... Doesn't seem quite what I'd expect to be lighting up those plugs. -kinda slow.... So now I'm thinking coil again. maybe the stocker isn't up to the task..... IDK. I'm gonna put the point and condenser back in and see what happens. I gotta get on the lake this weekend and I don't have time for the tech runaround. PERTRONIX YOU HAVE FAILED ME!!!

 

[SSTKO81]

Re: 3 requirements for proper ignition (140)

OK, heres the reason for no spark: The purple wire.... The resistance wire running to the coil that supplies it with ~10v has its origins all the way up under the dash at the ignition switch. Somewhere along the line the wire was pulled out of the ignition wiring harness. Thus, the coil was only getting the full 12v while cranking and had no juice once the key was released. (if I understand that right) Also, just as a side note. That same purple wire is the trigger wire for the old alternator. (didnt realize that)
So all that explains the spark issue. The engine's still not starting, but now I tend to think its a fuel problem as I diffinately have spartk to all for cylinders. Thanks everyone for your insight and help.