chuckd71

iTrader: (23)

I generally try to bump older semi-relevant threads when possible but there are potentially lots of variables here and that approach could get confusing.
Anyway, when I crank the car to start the voltage drops like a rock then it's 50/50 that it'll come back then start. Battery is new, checked and charged. Once the car gets going the alternator keeps things above 14v, but getting it started is the hard part.
Here is a video of what is going on, voltage is top right gauge. Is there a general sort of thing that usually causes this? It's been going on for a while but this is the first chance I've had to try to fix it.

LLLosingit

iTrader: (4)

Could be a few things, The starter could be drawing more power than normal (going bad) Battery cables possibly to small. To much compression. Timing could be off in the tune.

CattleAc

iTrader: (7)

I guess I would find a friend with an amp probe and see how much your starter is drawing first, and go from there...

chuckd71

iTrader: (23)

Compression checked out okay when the motor was put together, tune is recent but that of course doesn't mean perfect.
The battery cables are short and good quality (I took them from a newesh wrecked BMW that had the battery in the trunk but am using 2 feet of it instead of 20). I had planned on replacing both it and the grounds anyway. Perhaps the starter is going bad, I can try and replace it tomorrow. The guy I had tune it is left town for a couple weeks but I'm going to have him check it out again next time I get into town.

Old Geezer

iTrader: (3)

Volt drop test across all connections done?
Ground integrity checked?
Engine ground directly to batt?

joyridin'

iTrader: (1)

Yours sounds more like a timing issue, but here is what I ran into.

The voltage meter is reading the voltage as is seen on the dash board, not at the starter itself. If the wiring going from the dash (ignition switch) to the solenoid is small, you will get what you (and I) were/are getting. There isn't enough voltage amperage to activate the solenoid correctly.

I added a relay before the solenoid. The solenoid wire now goes to activate the relay. I ran a larger wire into the relay and from the relay to the solenoid. The car turns over faster and there is no drop anymore. Not sure if it will work for you or not.

MontecarloDrag

iTrader: (3)

Ground wire must go from battery to engine block.
If timing tables are stock and wiring is good, then the starter is going bad.

xXLindquistXx

iTrader: (7)

my car is doing the same thing. new battery and starter. would like to know what fixes it.

joyridin'

iTrader: (1)

I just stated what fixed the same situation in my car. You are not supplying enough voltage to the starter solenoid. Try running the starter solenoid off a relay instead of directly from the ignition switch.