[zipfactor]

Hey everyone

I have a 350 sbc in a '76 trans am. I am having a problem with starting the car. I checked for power at the batt terminal on the distributor with the key on and got 12 volts. I checked the power while cranking and had about 10 volts. I pulled a spark plug from the engine and grounded it and then cranked the engine and got no spark. I tried swapping the coil out with one I had lying around and still had no spark. :sweat: I am not sure what else to check, maybe the ignition module itself in the distributor? If so , how would I check it? Could this be a bad grounding issue? Any suggestions would be great, thanks all.

Ben

 

[DoubleVision]

Check the ground inside the distributor, make sure it`s clean and tight, next check for broken wires, if all looks good either the module or the pickup coil is bad.

 

[nitro_baller4692]

more times then not it's the module.

 

[Blazin72]

I would just say "ditto" but I got a message saying my message is too short so I'll rephrase that by saying I too think it sounds like an ignition module, that is not an uncommon thing to happen.

 

[docvette]

Doc here, imp:

Pull the module and have it tested at auto zombie..for free..If it is Bad, have them test the new module. These have an Abysmal Failure rate right out the box...And once you leave the store It's your problem, not to mention screw up your trouble shoot on a bad "NEW" module..

On replacement (new or Old) BE SURE you clean off the old heat sink compound and apply the new compound (generously, but not sloppy ) to the new or old module before installing. If you don't you'll be doing it again in a few days to weeks..

If not the module , then look at the pick up..to replace that you need to pull the Dizzy and disassemble the dizzy .. To test it, get the resistance readings for your year car, (there is a cut off, where under a certain date they are one value, and over that date were a different value) If it is 000 at all you need another.

Doc imp:

 

[steve t]

sound like a module, i had to climb up on a hot engine on the side of hwy one day to replace one, that was no fun at my age, my wife wanted to call a tow truck, i said hell no

 

[zipfactor]

thanks you guys :thumbup: always quick with the responses. Ill check those parts out and let you know what it was. thanks!

 

[RPM]

Sounds like the module, but could also be the pick up coil. Whay not put a new dizzy in it and be done with it. You can't beat this price..

http://cgi.ebay.com/ebaymotors/CHEV...emQQcategoryZ33690QQihZ016QQitemZ260054122411

 

[zipfactor]

Wow, that is a great deal. Have you personally purchased one? I would like to know how good of quality they are if I did consider dropping my old distributor. Either way I'd still like to find out what happened before throwing parts at it. Thanks all.

 

[zipfactor]

Update:

I tested the pick up coil, and it was within spec. I had the ignition module tested at advance auto, and it checked out. When they tested it they heated the module up by testing it multiple times and it was ok. I put the dizzy back in the car, and pulled a plug and grounded it. When I turned the car over it sparked. The spark didnt seem that bright though. I stuck the plug back in and tried firing it. Nothing. I tried adding more grounds to the distributor body and it still would not fire. I added some gas to the carb throat and it still would not fire. I tried finding tdc on the #1 piston and re timing it, turned the car over and still nothing. Could it possibly be bad windings in the pick up coil? I have 12 volts at the batt terminal with the key in the on position. What do you guys think? Thanks for the help.

Ben

 

[Sir Joab]

Pardon my unfamiliarity with non-MOPAR stuff, (I grew up around MOPARs)but does your system have a ballast resistor? If so, it might be that component. I've been puzzled by those little buggers many times. It might also be a cracked spark wire from the coil to the dizzy that's "leaking" electricity to the block? Just a couple ideas.

 

[docvette]

Doc here, imp:

Did you check to see if you had 12 volts in the cranking mode? If it drops out in start..It won't fire...

Quick and easy test..run a jumper wire from the "BATT" terminal directly ro the battery, try to start it..If it fires and runs..you need a secondary Ignition OR a better location to hook the BATT wire..(HOT in all modes)


Doc imp:

 

[docvette]

Doc here, imp:

You should NOT have a Ballast wire or resistor with an HEI..IF you do...that's why it isn't firing..

Doc imp: imp:

 

[zipfactor]

i forgot to mention that. Yes I do have 12 volts on cranking.

 

[T-bucket23]

The connector for the module could also be bad causing weak or intermittant spark. Check it for Green gunk.

 

[docvette]

Doc here, imp:

Sounds like the Ignition Coil is bad..Did you test that also?

Doc imp:

 

[zipfactor]

Yeah, that was tested also. I cleaned the connections on the ignition module, and made sure to put heat sink grease on it. I'm at a loss. Thanks for the quick responses

 

[zipfactor]

I think I am going to purchase the new distributor off of ebay that rpm had listed. Is it possible that the magnet on the distributor shaft could have gone bad? I was just noticing that I can pull the bottom of the gear up and down probably a 1/4 of an inch. Is this typical?

 

[nitro_baller4692]

your going to have some end play.
not to sound like an a hole but is the button with the spring and rubber gromet still in tacked below the coil.make sure the spring is not broke,that should also have electrical grease as well.also make sure the rotor is not burnt.
i'll check some more things and get back to ya.

 

[zipfactor]

"not to sound like an a hole but is the button with the spring and rubber gromet still in tacked below the coil"

You dont sound like an a hole, sometimes it is the stupidest things that can cause big problems. I checked the spring and rubber grommet when I replaced the coil, everything was fine there. The rotor is fairly new, and is not burnt.