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Old 02-16-2005, 07:14 AM
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Voltage drop

I might have 15 volts when the motor's just sitting there but if I crank it, I'm only getting 8 or 10. How could this be? It's a brand new Painless Wiring harness and the battery is fully charged. I went through the manual again and everything seems to be right. It's an flamethrower HEI. Any thoughts?
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Old 02-16-2005, 08:11 AM
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Voltage drop during cranking is common. That is the battery's #1 job so it works really hard at it. As long as it starts the car and charges up after a few minutes of running, things are fine. If you are really concerned about it replace the weenie factory battery cables with some healthy O or 2-O cable. That will greatly reduce starting current resistance.

See this chart.

Last edited by willys36@aol.com; 02-16-2005 at 08:16 AM.
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Old 02-16-2005, 08:26 AM
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Sorry I guess I should have explained more. The truck won't start at all. It's an optima yellow top battery. I have really thick battery cable probably 0 and I'm wondering what the problem is.
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Old 02-16-2005, 09:29 AM
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Does the engine crank and doesn't fire or doesn't crank at all? Totally different set of problems depending on what the symptoms are. Is it a GM with integral starter/solenoid or Ford w/ remote solenoid? If it cranks, do you have spark at a plug?
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Old 02-16-2005, 01:49 PM
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The engine does crank and there is spark at the plug.
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Old 02-16-2005, 02:00 PM
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spark, air, and ?

Gas probaly went sour. Syphon gas out. Drain carb. Put in new gas and crank engine with fuel line disconnected to clear line. Re-install fuel line. Car will start.
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Old 02-17-2005, 09:01 PM
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Theres new gas and I still have this problem. I tried running a line straight from the battery to the coil with no results. You guys have no idea what I'm going through with this.
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Old 02-18-2005, 08:47 PM
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sorry i messed up this post

Last edited by njbloodline666; 02-18-2005 at 08:52 PM. Reason: messed up
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Old 02-18-2005, 08:49 PM
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does the motor actually turn over and not start. or does it not even turn over? and also (if it does turn over) did this happen after you put the distributor in, you maybe a tooth or 2 off or even 180 degrees out. if it doesnt even turn over check your grounds for corosion. do you have a tbi system, if you do you may have a bad tps and your pcm is stuck in clear flood mode. more info is needed
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Old 02-27-2005, 04:59 PM
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I'm with bloodline here. I'd try re-timing your distributor, and not worry too much about the v-drop. 8-10 is a normal cranking voltage.
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