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Posted

454 vortec - replaced a lifter after I got sick and tired of the ticking noise it was making, that Ofcourse means I had to pull the intake and distributor, after the swap I put the intake back on and installed the distributor, I didn’t think to mark it when I pulled it out so I brought #1 cylinder to tdc compression then installed the dizzy so that the rotor would point to the number one point, put everything back together and now cranks but no spark. I’ve spent the past couple days messing with it and at this point am at a loss, I pulled the top plenum and plugged all sensors in and such, coil and the cam sensor. The injectors will pulse and when I put a multimeter between the plug wire and ground I will get a fluctuating voltage. But no spark, and help is appreciated and thanks in advance 

 

first post here so let me know if I left anything out, 

kevin

Posted

Check the coil for power and a ground pulse. if that checks it's the coil, if no pulse maybe ignition module is bad

Posted
Just now, richard wysong said:

Check the coil for power and a ground pulse. if that checks it's the coil, if no pulse maybe ignition module is bad

I checked from the plug to ground and it read 12v with key in ignition, and would load-safety my multimeter when I cranked it over, it’s a 1000v multimeter

Posted

So if it has a good primary but still no spark you have a bad coil. the spark would be over 50,000 volts and with the coil wire disconnected from the coil should arc to the coil body or bracket if the coil is healthy. If you have good spark at the coil suspect the ignition rotor. An inline spark tester is an inexpensive and handy diagnostic tool

Posted
1 minute ago, richard wysong said:

So if it has a good primary but still no spark you have a bad coil. the spark would be over 50,000 volts and with the coil wire disconnected from the coil should arc to the coil body or bracket if the coil is healthy. If you have good spark at the coil suspect the ignition rotor. An inline spark tester is an inexpensive and handy diagnostic tool

I will be picking up a spark tester tomorrow, I just checked the primary and secondary resistance on the coil and everything is on spec according to my Haynes manual

Posted
10 minutes ago, kevin camps said:

I will be picking up a spark tester tomorrow, I just checked the primary and secondary resistance on the coil and everything is on spec according to my Haynes manual

Does the coil timing have to be spot on with when the rotor passes the point? Just cranked the engine to see the coil arcing to ground consistently

Posted (edited)

No. Examine the ignition rotor for a burn mark or carbon arcing, also the dist cap. when I reset a distributor the rotor should be pointing straight forward if it's up on # 1 compression stroke, there should still be timing marks on that engine. you will need a TechII or equivalent scan tool to set the timing but you can get it close with a timing light

Edited by richard wysong
Posted
4 minutes ago, richard wysong said:

No. Examine the ignition rotor for a burn mark or carbon arcing, also the dist cap. when I reset a distributor the rotor should be pointing straight forward if it's up on # 1 compression stroke, there should still be timing marks on that engine. you will need a TechII or equivalent scan tool to set the timing but you can get it close with a timing light

Here’s the rotor, I gave everything a quick sand before it got put back together, I find it very strange because everything worked fine before I took it apart

8E3BB5E3-6422-4E48-8807-14ACF8D5D395.jpeg

Posted

Well you are losing the spark somewhere between the coil and the plugs. Bad coil wire? Remove the rotor and look at the bottom for a burn mark, closely examine the dist cap for damage to the coil connection and carbon tracking.  Are you sure there is no spark at the plugs? I guess when you get your spark tester it will be easier to determine. You are sure it was TDC #1 compression and not 180 out when you dropped the distributor in?

Posted

UPDATE: 

picked up a brand new distributor, plugged her in still no cherry, I pulled the cap off and between the center hot electrode and ground I get a good strong spark, but then from the #1 cap plug to ground nothing, even if I shove a regular wire in it.  It seems like the cap might somehow be shorting to ground somewhere. The plot thickens haha

Posted

Did you check the rotor? Spend the $10 and put a new 1 on. You replaced the distributor or the dist cap? The spark is shorting to ground through the rotor most likely

Posted
Just now, richard wysong said:

Did you check the rotor? Spend the $10 and put a new 1 on. You replaced the distributor or the dist cap? The spark is shorting to ground through the rotor most likely

Brand new rotor and cap came with the dizzy 

Posted

Well that only leaves the wires as a possibility. Why did you replace the distributor? you had spark at the coil. Is the distributor turning while cranking?

Posted
Just now, richard wysong said:

Well that only leaves the wires as a possibility. Why did you replace the distributor? you had spark at the coil. Is the distributor turning while cranking?

Yeah distributor turns while cranking, I put a new one in because the old one has a good amount of play. I’ll mess around with it for the rest of the afternoon and see what comes up

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