I've never been much at electronics so it is no surprise I can't get my Jacobs ignition working. I finally received the right wiring harness in the mail and installed the CPU and coil according to the diagrams but I think the coil is no good. Might have arrived that way or MORE likely with my tinkering I wrecked it.

I've hooked up everything according to the pics (instructions) and the car turns over but doesn't start. There isn't any optional ways to hook it up. The CPU makes all the right codes but it won't start.

Does anyone know how you would test a coil to see if it was no good ? Will one of those multi-meters do -- if so any idea what scale do you test in (I will buy a multi-meter if needs be) ?

thx,
RP.

 

Try one of the local garages or maybe they can point you in the right direction. I know the regular OEM coils can be tested, unfortunately I don't know how...I just know that it can be done.

 

Before you jump overboard and start purchasing things you may not need you can do this simple test.

When you put the in the key, you see the oil light turn on with the SES? That's the first indication that the fusible link is functioning. Now crank the starter. Does the needle on the tach wiggle? Shut it off and it should bounce. If the needle moves, you have a primary at the least and the coil may be ok.

Now to check the coil you have to check primary and secondary resistance and see if its up to the specs of the ignition you purchased if its way off or non existent. If it isn't even remotely close to the spec the coil is bad. This can be done with a multimeter. I stated the first test to check due to the fact that multimeters (good ones) can cost a bit and the resistence being tested is small <1 Ohm. The primary is for the heavy wire while the secondary is the thinner finer wire.

To test for spark I recommend a spark tester, its inexpensive and you won't risk the car or you. The amperage from that spark can reach as high as 1 amp and it only takes like 2 milliamps to stop your heart. The old way was to stick it against ground, but there have been cases where it shocked the person. It is fatal hence why the coil should say something like that. Fatal amperage/voltage or something.

 

hey man thx for the test procedures ! I'll do that SES light and watch the tach etc. as for buying stuff I am already into this silly ignition for hundreds so another few bucks on a multi-meter isn't gonna mean much at this point. I just wanna get the darn thing working !!! Oh yeah thx I'll try not to kill myself as well. Got a story to tell about that one time I ground a screwdriver across the coil wire to the firewall -- could feel the sbc firing order running through my body don't ever wnt to do that again !

Hey are you going to dyno day tomorrow ?

RP.

 

Yeah I'm headed to the dyno day tomorrow. Your welcome, hope you figure out what's wrong. Remember to check the specs on the multimeter. All multimeters have an error correction, make sure the one you're getting has a smaller error correction than the reading your trying to take.
I have my own little shock story too, I was checking to make sure the boots were all seated ok and pushed hard on one and it fired at the moment I was pushing real hard. Felt a good amount of current surge though the hand onto the firewall through my right hand. I think back to other times.. the toaster and the stove and a wet counter, that hurt. My high school electronics class... we had a fence zapper which was low current and teacher thought it funny if two guys were fighting to have them both hold 1 terminal each and then try to punch each other. Memories... ahhhh... hehe

 

palric if you need a meter i can lend you one.

 

Yes coil shocks hurt. AcceldZ's Accel 300 digital ign. box gave me a whack off of a plug on day and he laughed. I couldn't move for a couple minutes. he tells me later that that thing puts out anywhere from 45000 to 60000 volts. that would explain this burn on the end of my finger that i still have after 3 weeks.

 

The voltage may be high, but its not that which hurt you the most. Its the current. It almost nears 1 amp which is way beyond the fatal current needed. With current anywhere b/w 50 mA to 200 mA can damage organs and stop the heart. That's milliamps 2/10 of an amp. Amperage is much worse than higher voltage, but high voltage can accompany high current. Remember static shocks are worth 10000 V but the current is so small < 10 mA to only make you feel it. Just how far did that shock travel? If it went from a point in your arm to another point, you may have some nerve damage (no joke) and another burn spot if you had one appear on your finger. We're talking 45000 volt and close to 1 A. I had a shock from toaster to stove from left arm to right arm and gave me an irregular heartbeat for 2 years until I had it corrected with some mild therapy. (Caused me shortness of breath) That shock wasn't even close to the level produced by a coil.

 

Hey Slade1 the tachometer test was pretty ingenious -- like to know where you learned that one ?

The coil must be toast I tried the test as you said and the tach needle did not move at all it was perfectly flat while the engine turned over.

I'll be ordering another coil next week.

thx,
RP.

 

Dad's an electrician and f-bodies are what he drove when I was a kid. If there's a problem with an f-body (stock problems mostly) I've seen it. I've also rebuilt my camaro from ground up after my dad gave it up. It took me 3 years (cash limited) to get it back to stock levels and just these last two years I started the task of exceeding stock levels. I always figured if you're gonna mod, start with a perfectly good engine that way no matter what you throw at it, it can and will accept the mod. An engine is only as good as the base you start with I think, and it helps if your engine is running the same as it did from the factory.