Ok guys I just did some engine work, swapped out the cam and bolted on a new set of heads with roller rockers and headers. Buttoned everything up and tried to start the car, no spark. Cranks well but doesn't fire.

Started to do some troubleshooting and pulled the distributor, found the pick-up coil was awefully corroded and the plug-in to the ignition module was missing most of the plastic housing and could have been touching the metal plate. So off to the parts store I went and I replaced the pick-up coil, ignition module, distributor cap, and rotor (I'd already replaced the plugs and plug wires when I did the engine work). Still no spark. Tested and replaced the coil, still nothing.

Checked the key on and cranking power to the coil, looks good. I'm at a loss here.. what am I missing? Before performing any work the battery was the first thing disconnected and the last thing re-connected. The entire ignition system has pretty much been replaced now with new parts, I do not have VATS. I've checked all fuses that I could find.

So I'm convinced that it is something I've overlooked during the engine teardown, perhaps a ground wire or missing plug somewhere. I've check all known grounds and rechecked all plug-ins to ensure they're making contact and don't have any bent pins etc.

What am I missing.. I've been trying to get spark since Saturday and now I'm becoming very frustrated and irritated!

 

If you have a separate diagnostic tachometer, does it indicate anything while the engine is cranking?

Is the distributor turning?

 

sorry no separate diagnostic tachometer.

the rotor turns when the engine is cranking.

 

I know you said there is no spark at the plugs, but put a spark plug on the end of the coil wire and crank. Is there spark there?

 

Sorry if I wasn't clear, there is no spark from the coil.

I have done just that, I have put a plug on the end of the coil lead and gounded it to check for spark, nothing. The problem is before the distributor.



Now I thought about this all night at work, here is my thoughts. I used my manaul to check the coil using a ohm meter, there is three tests. The book says if it fails any one test, replace the coil. One of the tests says to use a high scale and test one connection to the prong, the reading should be very high or infinate (1). My coil tested 008.

I assumed that was low and not very high or infinate as the book says, so I went out and bought a new coil. I brought the new coil home, took it out of the box and straight onto my work bench were I did the same three tests. For the same test as I mentioned above, the new coil read 009. Both coils passed the other two tests.

Now am I reading the meter incorrectly or do I have another bad coil straight out of the box? I suppose it is possible, although unlikely. I'm going to call my parts dealer tomorrow and ask a few questions.

Your thoughts?

 

Brisk follow this flow chart let me know where it leads you to.

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here is a pretty good schematic

 

Yes that flowchart looks awesome, another friend emailed that to me as well.. with any luck that will do the trick. I'll let you know how I make out.

 

ok I believe my problem is a ground issue.. some of you guys that PM'd me had it correct from the start.

looking at the wiring diagram I do NOT have "+" power at the coil, only ignition power when the key is on. anyone have any idea where that specific ground is??

..or where should all the ground be (connected to and/or comming from) under the hood with a TPI? I can't seem to find any loose wires hanging around anywhere and the grounds seem to test fine, so..

it is either a ground that I have overlooked and not connected, or I have a broken wire somewhere.

but seriously guys, thanks for the help so far!

 

Is the distributor still bolted to the engine?

Then you don't have a ground problem. It grounds itself by touching the castings.

This is just car electricity, about the simplest kind of circuitry that there is. It's not voodoo or black magic or even rocket science. It's all real simple. Don't let people talk you into outsmarting yourself with stuff like that.

You're supposed to have 12V on the power feed to the dist ONLY when the key is in "On". Otherwise, it would be rather difficult to turn the motor off. So that's exactly as it's supposed to be.

Changed out the module yet? Having had about 3 or 4 of those to just up and die on me in various cars over the years that I can recall off the top of my head, that would be the VERY FIRST thing I'd do. In fact, I'd estimate the probability of that fixing your car, at over 95%. (i.e., less than 1 chance in 20 that your problem is ANYTHING BUT the module...)

Go change the module, and come back and tell us how the car runs.

 

sofakingdom, I changed the module on Saturday or Sunday.. so you've lost that bet.

I do not have 12v power at the coil.

 

and then

That's what you're supposed to have. The pink wire should have 12V when you turn the key on. 12V should go away when you turn the key off. You say that's there. OK, you have power to the coil when you're supposed to have power to the coil.

So what "power to the coil" is this, that's missing?

Are you sure you have everything plugged back in like it's supposed to be? Have you tried another module?

 

The big pink wire at the coil should have +12VDC when the ignition is ON. The pink/black wire at the samm connector should also have power. That pink/black wire should be connected to the distributor, along with the big white wire from the coil. If that's all intact, and the coil isn't making spark energy, there isn't much left but the switching/amplifier module and the pickup array.

Instead of using a spark PLUG to test for spark, use a spark TESTER. If your spark plug happens to be wet/fuel soaked/damaged you won't see any spark at the gap, even though the rest of the system is working properly.

 

A spark plug in free air will also fire with a measly thousand volts or so, but it might take 10,000 volts or so to fire a plug in the chamber with a compressed fuel-air mixture. Spark testers (costs about $5 at Lordco, hanging on the rack with the K-D tools) are calibrated to fire with something like 25,000 volts in free air.

 

Ok so two wires should have power, I only have one. The one wire that does have power is only powered with the ignition and it is the grey plug from the pink line. Thats the only lead that has power to/from the coil.

According to the wiring diagram posted above the black plug should have one wire with "+"

 

Are you measuring this with the plugs unplugged? If so, then that's why you think you have a problem there.

As you can see from the diagram, the pink wire in the black connector gets its switched ignition power from the pink wire in the grey connector. So, that wire will only have its power when everything is all plugged in.

In other words, the grey connector brings power in; the black connector carries some of it over to the module.

I don't know about any pink/black wire at that connector. Pink/black is the fused ignition to ECM-related components, which the distributor and coil are not, in this particular context.

 

ok so I gave up and couldn't figure this out.. I needed another set of eyes to have a look at my prob and try to lift some clouds. turns out that is exactly what I needed, I was staring at the problem the whole time but couldn't see it.

darn near every plug under the hood is different and only plugs into one spot.. however there are two identical plugs, one from the coil and one on the intake air sensor, so of course I had one plugged into the other and neither was in the correct spot. flipped the two plugs and replaced them where they should be, car fired right up. right away we realized the distributor was 180 deg out (plus one tooth) pulled it, dropped it back in... volia. runs and starts great now..

..and damn those open headers are loud! y-pipe will be welded up and installed tomorrow and I'll have my baby back on the road again.

then I get to dive into the abyss of custom tuning and chip burning. thanks for all the advice guys.