Hey guys,
I'm new to the site but have been working with third gens for a few years now. I have an 83 Z28, Crossfire Injected 305 with 67K original on the car. Over the winter I did a carburetor conversion. The car started and idled well after the conversion, started for the first time two weeks ago. Would bog at low RPM and stall under load at low RPM. The Holley I had on it was old so I replaced it with an Edelbrock carb and when I went to start the car, it appeared that the solenoid wasn't getting constant power. The starter gear would rotate the flywheel a few turns and then click. The starter "passed" at my local shop but I replaced it none the less. When I went to crank with the new starter installed, the battery gauge shot down to below 8volts immediatly. The battery would not accept a charge so I threw in a fairly new battery that I had lying around my garage that held a constant charge. I cranked and it did the same thing. The starter will turn gear for a short amount of time and then pull power too low to crank. When this happens, everything else works and is at full power. I decided to try cranking again and my positive terminal cable smoked at the battery connection and then smoked amply at the solenoid. I took the key completely out of the ignition, and while the key was inhand I stood at the front of the engine bay and watched my engine slowly still rotate as if I was cranking still. This doesn't stop unless I tap my ignition cylinder a few times. So my symptoms are a constant but temporary surge when the starter is engaged and a rotating starter with no power to ignition. It is acting as if it is in a constant "loop". I hooked my connections up right, ignition to the s terminal of the starter.

So all of this rambling has been done with a few different people and all I can come up with is either a bad solenoid or a bad ignition cylinder. Would a bad ignition cyl. temporarily surge power like that though? PLEASE ANY THOUGHTS WOULD BE HELPFUL!

The mods of the carb conversion were: Edelbrock 600cfm electric choke, Edelbrock Performer intake, MSD Distributor, MSD cap and rotor kit, Vacuum advance canister and Mallory Fuel Pressure Regulator, return type. Like I said, the car would start on a dime up until this recent problem.

Thanks for reading and I look forward to hearing back from a bunch of fellow third gen guys!

-Chris

 

How are your battery cables? Corrosion can do weird things. Check you cables to see if the corrosion is creeping down the cables. It usually starts where the cable connects to the battery and works its way down the line. The insulation on the cable might be bulged or splitting if it is bad enough. You can also cut the insulation with a knife to see if the wires inside are copper colored or if the white corrosion had crept in.This can cause excess resistance and you won't get full power to the starter, even though it might be trying to draw everything your battery has.

I also worked on a Blazer that had a similar problems. The starter would crank, even after pulling the key out, until the wires would melt or they were disconnected. I changed the starter solenoid and it still happened. Then had the starter tested. It tested fine but replaced it and it seemed to start fine. While I was under the truck I also noticed a bare spot on one of the cables that was caused by rubbing the frame. I taped it up when I replaced the starter. So I am not sure if the bare wire could have been causing a problem or if it was just the starter. Check for that too.

Good luck

 

I appreciate your advice. I'm really leaning toward the starter itself. Like you said on the Blazer, it rotates when the keys out. I was thinking ignition because of the random rotation but this problem didn't occur when the old starter was properly working.