Track update!
Senior User
Joined: May 2002
Posts: 160
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From: usa
Track update!
Here is some more info: I took voltage readings off of my postive coil wire. It has 12.75 volts with the key on and not running. Idling it has 12 volts and at 2,500rpm it goes all the way down to 9. Is this normal.
don't know a lot about engines, but i do know this voltage drop aint right. at the battery you should have at least 12.5-13 volts at idle and no less than 14 volts at higher rpms. try checking it again at 2500 rpms if your still getting low voltage trun on your headlights and see if it doesn't drop more. sounds like you got a bad alternator or voltage regulator. the lower voltage will cause your engine to do all kinds of weird things.
don't know a lot about engines, but i do know this voltage drop aint right. at the battery you should have at least 12.5-13 volts at idle and no less than 14 volts at higher rpms. try checking it again at 2500 rpms if your still getting low voltage trun on your headlights and see if it doesn't drop more. sounds like you got a bad alternator or voltage regulator. the lower voltage will cause your engine to do all kinds of weird things.
Post Fiend
Joined: Feb 2001
Posts: 6,624
Likes: 8
From: Missouri
Track update!
I use NGK TR5 plugs. They have never given me any problems but that doesn't mean anything. I don't think I have a resistor because if I did I wouldn't have 12.5V to the coil without the engine running. Your idea doesn't sound bad at all bikerwolfe. That voltage regulator has been there for a while. Another question. Does anyone think poor quality gas could do this? I filled up on 91 and put a bottle of 104 racing in it instead of getting 93 because the sinclair station wasn't open. I don't know why but I can't make this engine detonate. If i advance it too far it just runs like crap but never pings. Is this normal. I have never seen an engine that wouldn't detonate before it starts running like crap.
Senior User
Joined: Oct 2001
Posts: 306
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From: Hollister, CA
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I could be wrong, but I thought the ballast resistor was to limit current to the coil. During starting the ballast resistor is bypassed by the starter soleniod. As the load increases - RPMs - the voltage will drop.
In my 1969 manual, there is a battery to coil voltmeter test. Basically hook up a volt meter, place a jumper wire from the distributor side of the coil to a good ground, turn on the ignition with all other accessories off, and read the voltage. It should be between 4.5 VDC - 6.9 VDC. If you are reading lower than that replace the ballast resistor. You might want to give it a try.
Reggie
In my 1969 manual, there is a battery to coil voltmeter test. Basically hook up a volt meter, place a jumper wire from the distributor side of the coil to a good ground, turn on the ignition with all other accessories off, and read the voltage. It should be between 4.5 VDC - 6.9 VDC. If you are reading lower than that replace the ballast resistor. You might want to give it a try.
Reggie
Post Fiend
Joined: Feb 2001
Posts: 6,624
Likes: 8
From: Missouri
Track update!
Well its not the voltage regulator. I am accumulating a crap load of spare parts though. Where is the ballast resistor on my truck? I can't see where the positive wire goes after the firewall. I have looked and looked and can't find it. The theory makes sense. My coil doesn't require a resistor as it is the same ohm as the pertronix coil (accel super stock). If I do have a resistor it has to come out completely. Also from what you all are saying I am really starting to lean on that.
Senior User
Joined: Oct 2001
Posts: 306
Likes: 1
From: Hollister, CA
Track update!
Well, if your coil does not require the resistor wire, just run a jumper from the positive side of the battery to the positive side of the coil and go for a test drive.
The ballast resistor in Fords is actually a resistor wire. It is pink in color. I believe there was a previos post about how to bypass it.
It goes between the ignition switch and the 3 connector plug that also has the oil pressure signal and water temp signal. The soleniod wire also joins the cab side of the connector at this point. It is brown I believe.
Could also be a bad coil, I've had that happen before on a new coil after a couple hundred miles. Started missing on the freeway.
Hope it helps,
Reggie
The ballast resistor in Fords is actually a resistor wire. It is pink in color. I believe there was a previos post about how to bypass it.
It goes between the ignition switch and the 3 connector plug that also has the oil pressure signal and water temp signal. The soleniod wire also joins the cab side of the connector at this point. It is brown I believe.
Could also be a bad coil, I've had that happen before on a new coil after a couple hundred miles. Started missing on the freeway.
Hope it helps,
Reggie
Senior User
Joined: May 2002
Posts: 121
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From: Rimbey Canada
Track update!
Actually at least in my 70 sport custom the ballast resistor is on the firewall on the drivers side, it is about 2 inches by one inch and has a fuse on it.
Ashes to AShes
Dust to Dust
Without ch*vs
our tools would rust
Ashes to AShes
Dust to Dust
Without ch*vs
our tools would rust
Lead Driver
Joined: Apr 2001
Posts: 6,175
Likes: 21
From: Texas
Track update!
A poorly driven stock LS1 powered Camaro SS is capable of 14 second ETs. A well driven SS can go low 13s, and have even seen high 12s. Your truck must be running much better than the 14.6 stated in your sig.
Post Fiend
Joined: Feb 2001
Posts: 6,624
Likes: 8
From: Missouri
Track update!
It ran a 14.6 with a 3.25 open differential and shifying at 5 grand.
It noew has a 3.70 spool so it should be doing much better.
It noew has a 3.70 spool so it should be doing much better.
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Post Fiend
Joined: Feb 2001
Posts: 6,624
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From: Missouri
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Yup, if both tires aren't turning at the exact same speed 100% of the time with a spool something is broke. It does squeal going around corners but it only jumps on the roughest pavement and even then it isn't that bad. Keep in mind I don't drive in the rain or snow and highway use is limited. My crown vic has traction control and handles much better on slick road so I just use it.
Lead Driver
Joined: Apr 2001
Posts: 6,175
Likes: 21
From: Texas
Track update!
That's what i figured. I may have to get some traction improvements if I ever get the horsepower up to where it ought to be. I'm thinking I should take a look at those pistons again, to se if they are really bringing down my compression ratio. Every thing else seems to be working well but the power is not all that great.
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