labrat Posted February 9, 2002 Share Posted February 9, 2002 Ok, here's the deal. I've finished my conversion, small block all in place, try to start the motor, and no spark. All of this ran fine when in the 72 truck I pulled it from. After much troubleshooting, find out that the voltage to the HEI dist. is dropping to about 8 volts when I crank the motor. I'm pulling voltage directly off the battery for this (thru a relay) but it's still not enough. I have a 625 CA battery and even jumper cables to my girlfriend's car is not enough, the voltage still drops. Do i just need a bigger battery, or is something else going on here? Voltage is also dropping at the battery terminals themselves. I am running a remote battery in the trunk, is 1 guage wire big enough for this? I am at a loss and getting really frustrated here! Thanks for any and all assistance! Bill Quote Link to comment Share on other sites More sharing options...
Tim240z Posted February 10, 2002 Share Posted February 10, 2002 I sounds like the wiring to the starter is causing the problems. Make sure that the 2 circuts aren't on the same wiring. You could try using a second battery to power the starter to see if that solves the problem. If it does then you'll know where to start looking. I'm sure there is some specific problem, but since no one has responded so far...try this. I think the starter is pulling voltage away from the coil. Tim Quote Link to comment Share on other sites More sharing options...
Kevin Shasteen Posted February 12, 2002 Share Posted February 12, 2002 My high school buddy & I had the same problem: different car-but same problem on two separate occasions. 1st Time: Solution: The battery cables-even tho he swore he tightened them-they were not tight & were loose causing the voltage drop....tightened the cables at the battery & the car started up immediately. 2nd Time: Solution: after pulling his & my hair out we decided to attach a ground stap from the back of the engine to the firewall (even tho this car DID NOT originally have one) and the car started up immediately. The only thing we could think was that somewhere in our R&R of the engine we altered the grounding of the wiring somehow-the ground strap from the firewall to the back of the cylinder head was the cure. You can buy these groundstaps brand new at any auto parts store: Look for the Red "Help" Card isle items. Questions: 1)Are you running only one battery from the back to the front 2)Or are you running two 620-650Amp batteries from the back to the front. IMO: if you're only running one 650 battery from the back to the front on a Hi/Perf.Engine...you're CCA's on the battery may be two small for that much "footage" of cable. On any Hi.Perf.Engine I ever had; I always liked "Overkill" such as a 1000CCA from Champion. May not have needed it but I've never personally had a cranking prob on any of my own cars: granted-the battery was always in the stock location-up front under the hood. Kevin, (Yea,Still an Inliner) Quote Link to comment Share on other sites More sharing options...
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