Help, engine just quit, no spark

Hi everyone, I need some help from you Chevy gurus. From my other posts you know we just bought a street rod. Now we are proud owners of a non starting street rod.

Its got a crate 350, with HEI, Edelbrock 600 on it too. I was told about 2000 miles on it, but it sat for a bit.

The order of occurances up to now are.

Driving down the street, eveything ok, running fine, stopped at the store for 10 min or so, came out and started it, and it ran like crud. It hardly idled in drive, surged and shuddered, no backfiring though.

Well, since I was told it had sat for a bit, I went and got plugs and wires for it.

Replace said plugs and wires, the plugs were shot, porceline cracked and broke on a few, even being easy on them. Easiest plugs I ever replace though, just take the side panels off and had them done in 10 min, beats the 2:5 hrs it took to do my Super Bee with headers.

So I started it up and it ran the same, surging, idled like crap, rev it up and it was ok till you tried holding it steady, then it surged again.

Soooo. Hmmm looked at the carb, and there was no filter on the line, great, probably got crud in it. So rebuilt the carb. It was bad too.

Rust and corosion yuck. Rebuilt, put it back on, and it still ran the same. Still stumbled at idle and shook and shaked.

Thinking I may have got the firing order wrong, I checked it again, found TDC and looked at the rotor, seemed ok. Tried again, no start.

Checked the dist wires and tried again, no start. Checked for spark, no spark. Grrrr. Ok, so the coil. Replace the coil, still no spark, wtf, what else controls spark on a GM HEI coil in cap?

Don't know what else to look at

sounds like your distributor went south if you are not getting any spark or it is frying the plugs.

The module in the HEI went south.

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Originally Posted by jyardgirl

sounds like your distributor went south if you are not getting any spark or it is frying the plugs.

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No spark at all, Is the module the flat thing on the distributer base? Yes i am a uneducated GM guy, feel free to make fun of me now.

Yes, under the rotor and remember that the only dumb question is the one that isn't asked.

I don't think anyone on this forum will make fun of you for not knowing something. It's not that kind of forum.
Yep, that would be it under the rotor. When I had a car or truck with an HEI, I always carried an extra module in the glove box, along with the proper tools and light to change it at 2:00 O'Clock A.M. on the side of the freeway. Don't ask what I was doing on the freeway at 2 AM. :whacked:

If you want to get cozy with that HEI and blueprint it, here's a pretty good tutorial...
Ignition 2 HEI

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Originally Posted by NTFDAY

Yes, under the rotor and remember that the only dumb question is the one that isn't asked.

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Hmm, I guess thats the only thing that hasnt been replaced. Gotta go get one and try it, are they specific, or the same, my son has a 79 Monte with a V6 with HEI,

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Originally Posted by techinspector1

I don't think anyone on this forum will make fun of you for not knowing something. It's not that kind of forum.
Yep, that would be it under the rotor. When I had a car or truck with an HEI, I always carried an extra module in the glove box, along with the proper tools and light to change it at 2:00 O'Clock A.M. on the side of the freeway. Don't ask what I was doing on the freeway at 2 AM. :whacked:

If you want to get cozy with that HEI and blueprint it, here's a pretty good tutorial...
Ignition 2 HEI

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Thanks, just kinda being silly, well maybe not, been a Mopar guy for 30 +yrs, gotta learn some new stuff.

I hear ya though, a friend had a 73 Nova a while ago that ate starters. He carried one around too, i helped him change it on two seperate occasions both times at night, both times in the KMart parking lot

Owning a hot rod is like owning a boat........if you aren't a good mechanic when you get one, you will be much better after you own it for a while. :( Seems like there is always some issue to try to resolve.

My thoughts were the module too, and if you take yours to the auto parts store and tell them 70's-80's Chevy V8 and show them yours to compare, you might be able to find a match. Of course, if you get one of the store "experts" like they hire these days who only knows how to look up specific cars in the computer, you might be in trouble. We got one of those yesterday morning, trying to buy a slightly shorter v belt for my Son Dans rpu. I had to educate HIM about how the numbering system on v belts works because he was dragging every belt in the store out, just comparing length. :eek: After I showed him how the inches were in the part number he found the right one.

I have always thought modules in these GM distributors just go totally out with no warning like you got. Every one I have heard of failing worked one minute and then didn't work at all the next. But it is possible to have one fail and run crappy for a bit, then go, I guess. You might also check with a volt meter to see what kind of voltage you have coming into the module. Could be a bad ignition switch, wiring, ground, etc.

Don

Here is a little tutorial I found on line that might help you a bit too.




A vehicle ignition system includes the spark plugs, the ignition coil and the ignition module, which is also called the ignition control module. All of the parts work in conjunction with the control module to ignite the spark that causes a vehicle to start and maintain power. If the ignition module is faulty, the ignition system will fail. A vehicle will display various symptoms when the ignition module needs to be replaced.

Acceleration Problems
A vehicle may display acceleration problems if the ignition module is bad. It might hesitate or shake when the gas pedal is pressed. When decelerating followed by accelerating, the vehicle will often jerk and slow down before accelerating.

Temperature Issues
A bad ignition module can cause the temperature of your vehicle's engine to rise above normal. If overheating occurs, the temperature gauge on the dashboard will rise above the average temperature area. If you turn off the vehicle, and allow it to cool down, the gauge will return to normal. Once you start driving again, the vehicle's temperature will again rise above normal. This overheating and cooling pattern could indicate a problem with the ignition module.

No Power
If the ignition module is faulty, your vehicle may eventually not start at all. The engine may turn over, but cease to crank when you turn the ignition key. Continuously trying to start the vehicle will often produce clicking sounds from the engine, indicating that no spark is present in the ignition system.

Damage
Some symptoms are visible on the actual ignition module; therefore, inspecting the part will help to reveal any damage. The location of the module varies, depending on the vehicle. It may be mounted on the engine within the distributor, within an engine compartment or in the distributor housing. When the module has been located, inspect the surrounding bolts for cracks or extensive wear. Any noticeable damage is an indication of a faulty part. Also, the module should have a greasy substance on the back to protect it from the heat of the engine, otherwise, it must be replaced.



Don

Plenty of good advice here. I love this site.
Kurt

I have also seen the small wires that go into the module fail and cause alot of the symptoms you're describing. Not saying this is your issue but while the module is out, test for continuity across the small wires.

Welcome aboard. A common problem with these modules is the wire will break, , easy to check, very gently tug at it where it attaches to the module.
Don't be afraid to ask here, they are the greatest people with the most information you will ever find! brian

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Originally Posted by Oldmanb

Welcome aboard. A common problem with these modules is the wire will break, , easy to check, very gently tug at it where it attaches to the module.
Don't be afraid to ask here, they are the greatest people with the most information you will ever find! brian

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I am totally unfamiliar with the GM system. Where do i check voltage and everything.

On the cap there are three wire connectors, two in front, Tach and Bat, then the one behind them with the mulitple wires that goes down to the base of the distributer.

The coil i installed was a bit different, the one i took out had three wires, a black which looked as if it was a ground then the red and purple one, the new one had 4 wires, Black, purple, red and another black ground wire?

I just attached it to the other screw that held the coil in. Where is this modules that everyone is talking about?

Oh, i read the other replies again, the module is in the base. My son has a 79 Monte Carlo with a V6, would his work for testing, or would a V6 module be different than a V8

I think it would be different, but not sure. Here is a diagram for you.

Don

It is usually either the rotor or the HEI module. When you buy a new module, there are a couple of tips that will make your life easier......first, there are several variations of modules, defined by the number of "pins" or leads. Go to Tech's link and figure out which module you need. Second, dont buy a cheap crap module....you'll only be doing the change out again. Third, put the thermal grease under the module to dissipate the heat.

Look at your rotor. At the center on the underside, look for a small, pin sized black spot where the spark is arcing thru to ground against the distributor shaft. Many times, a module gets changed when the problem is the rotor. Many garages charge for a module change and fix the problem with a new rotor. Again, dont buy the crap brands that the off brand parts houses sell (Checker, PBs, etc sell crap usually)

mike in tucson

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Originally Posted by robot

Look at your rotor. At the center on the underside, look for a small, pin sized black spot where the spark is arcing thru to ground against the distributor shaft. Many times, a module gets changed when the problem is the rotor. Many garages charge for a module change and fix the problem with a new rotor. Again, dont buy the crap brands that the off brand parts houses sell (Checker, PBs, etc sell crap usually)

mike in tucson

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excellent mention :) i hadn`t worked on anything gm for nearly a hunnert years and had forgotten how many burned rotors i`d replaced

I haven't bought anything for GM in years and Borg Warner used to make good parts, don't know about now. The rotor needs to be of high dialectic strength to minimize arcing.

All good posts but if I might add a suggestion. From your 1st post you mentioned crud and rust in the carb and that it had been sitting for as while. Sounds like you may have water in the tank in addition to the other problems mentioned earlier. I would have the tank boiled out and the fuel line purged. The carb may need another complete cleaning too.:)

Jack.

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Originally Posted by NTFDAY

I haven't bought anything for GM in years and Borg Warner used to make good parts, don't know about now. The rotor needs to be of high dialectic strength to minimize arcing.

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thanks for the info, i will check the dist rotor, i am actually having a electrical guru from our club come look at it. It is probably something stupid and obvious.

He had me check for power at the bat connector, no power coming to the wire. Tried hotwiring it from the alt stud to the bat terminal on the coil and got a back fire then nothing.

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Originally Posted by rp23g7

thanks for the info, i will check the dist rotor, i am actually having a electrical guru from our club come look at it. It is probably something stupid and obvious.

He had me check for power at the bat connector, no power coming to the wire. Tried hotwiring it from the alt stud to the bat terminal on the coil and got a back fire then nothing.

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I replaced the cap, rotor and module, and it still didnt work, dang coil fuse

It sounds like your module is bad in the distributor. Take off the cap take the wires off of the module get another and put the supplied grease on it, screw it on and replace the wires.