Help! HEI troubles

[kline1]

I got in my nice day 78 Monza daily driver (Buick 231) and turn the ignition, the car would not start. Carb getting fuel, there was a burning odor... I took the HEI cap off the coil and discovered the coil had melted, it even leak oil into the cap. So I am thinking, hmm bad coil.

I did not have a spare coil, so I borrowed the coil out of my black 79 beater Monza (Buick 231). I decide to use the ignition module too; just in case the coil took its life. Still the white Monza would not start. I am getting voltage to the BATT terminal on the cap. Everything is hooked up.

So I am thinking, the only other possibility, maybe the pickup on the distributor was also gone. The resistance was still in specs (810 ohms), but I figure it could still be at fault. So I put the entire distributor into the white Monza. So at this point, the entire ignition system was changed (distributor, coil, module, rotor, cap, etc...). The shaft of the replaced distributor was about 30 degrees off from the original distributor. So I shifted the plugs on the cap.

While turning the engine over, I tried turning the distributor to get the alignment but it would not start. Then I hear the sizzle....

The coil was cooking; the plastic was starting to melt. I am thinking what the heck. Everything is changed, what could possibly cause the coil to melt? Could an Optimal battery cause such a condition (I hear they have a low internal resistance)? Could a faulty alternator? The battery voltage is fine at 12.6 volts. This is truly bizarre. I have two cook coils (possible fried ignition modules as well) and I have no idea what could be causing this. Has anyone ever experience or hear of something like this?

[heinz057]

is there a tach hooked up to the tach terminal on the cap ? if so could be a bad tach and shorting out the system

[kline1]

Bad Tach!!! I did not think of that, What is the best way to test this, short of replacing the coil, module and leave the tach unhook; and pray it does not fry another coil,

[spyder_xlch]

Which one of you're cars is the "nice day 78 Monza daily driver "? Anyway, did that car run before the coil melting happened? Are you hooking the "bat" wire to the correct terminal? you didn't connect it to the "tach" terminal did you? I'm not sure that would fry the coil though as I've never seen or heard of it happen. I doubt the battery or alternator would cause it either. you could try changing the alternator and see if it still does it but if that isn't the reason you'll burn out another coil. Is the distributer hold down tight and making proper ground? You told me you were going to Clemen's about that exhaust stud, take you're modules with you, they should be able to test them for you. Talk to Paul and tell him Matt from the Danville store sent you.

[spyder_xlch]

heinz057 must have replied as I was, but that's a good point. I had a bad tach on the Spyder i had back in the early 90's. I lost spark, put my spare dist in and still no spark. unhooked the tach wire and it fired right up. I forgot all about that, thanks for bringing back the memories heinz057.

[heinz057]

go to www.autozone.com and go to their repair info section it will show you how to test each part as long as you have a good ohm meter

[kline1]

Which one of you're cars is the "nice day 78 Monza daily driver "

Yes, it is her.

Are you hooking the "bat" wire to the correct terminal?

tripled check every time.

Talk to Paul and tell him Matt from the Danville store sent you

Thanks, I appreciate that. P.S. Your car is waiting, I got the bumper off, the hatch is ready to be lifted off.

I lost spark, put my spare dist in and still no spark. unhooked the tach wire and it fired right up.

I never even saw it could be an issue, I hooked it back up every time..... Tomorrow, I am buying two coils, check out the ignition modules, and hope nothing else happens in the mean time; my choices of transportation are dwindling.

[kline1]

She is feeling much better now.
She is lacking a tach for now.

Can something be added to the system like a diode or capacitor to prevent this from happening again?

[heinz057]

what was fried ? what kind of tach is it? and make sure the tach is good. the monte ss used to have a capasitor

[kline1]

My stock tach fried the coil (twice) in my 78 Monza HB (Buick 231). I will test the wires before changing out the tach. heinz057 was right on the money. But is there any way of preventing this from occurring in the future?

[zeke]

Sounds like the tach sent straight DC to the coil. Capacitors block DC and allow AC or pulsed DC signals thru. Try a .1 microfarad 50v capacitor in series with the tach wire. Usually the tach has this capacitor in it already.

[kline1]

Try a .1 microfarad 50v capacitor in series with the tach wire

Thanks, those are the values I needed. Looks like I will be making a pit stop at RadioShack. I am going to install one at the distributor. But I am also going to check out tach wiring to make sure there are no shorts.

[heinz057]

do an ebay search for monte tach there is alwas one for sale

[cjbiagi]

There should be a stock capacitor mounted on the intake or nearby bracket.

[kline1]

Thanks for the info, I placed a bid on one....

http://cgi.ebay.com/ebaymotors/ws/eBayI ... 0126867133




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