question regarding points ignition

[ColinOpseth]

hey guys,
I have 7.0v at the coil with the motor running. Is that too little voltage? What would happen if the resistor wire fries, would it cause 'less' voltage to the coil or 'more'?

As well, would running 7.0v make the engine sputter badly when it revs out? I have replaced the distributor, coil, cap and rotor on my engine. It is a 327.
Thanks,
Colin

[krue]

I can't really help except to say if a wire "fries" then resistance goes up and voltage goes down.

[ColinOpseth]

alright, so if i am only getting 7v at the coil with the engine running it is plausible to assume that the resistor wire is bad? i'm curious as to how much the voltage drops.. on my engine the only wire that goes to the coil comes from the solenoid ('R' terminal, I think) and it is a yellow wire. It remains 'hot' when the engine is running so I'm assuming that I have everything hooked up correctly.

thanks,
Colin

[ColinOpseth]

I guess it would help to give a quick rundown of my problem and what I've done so far..

I bought this car with the 327. The guy had the car for 4 months and could not figure out why the engine would not rev out if you push on the gas more than 30-50% throttle. It runs fine but hits a 'wall' around 2000-2400rpm. Basically, the engine starts to sputter, lose power, and run like crap. Only when the gas pedal is released will the engine stop sputtering. The engine will do it if you slowly rev up the motor when you are driving and then 'punch' the throttle, and it will also do it when you punch it off the line. Driveability of the engine is fine (I drove it from Sacramento to Los Angeles getting 15mpg) but the engine has absolutely no power and will not even squeal the tires. You'd think it should be able to with 3.73s and a 327!

Here's what I've done:
- Replaced the canister gas filter with a clear Fram G12.
- I noticed that the filter was only filling up 1/4 so I replaced the Holley mechanical pump that was on there with an exact replacement: Holley PN#12-834
- Felt no change whatsoever. The 'wall' is still there
- Removed the stock untouched (one month old) Rochester 4MV carburetor from my Dad's '72 1/2 ton 396 truck and put it on the engine. No change whatsoever in how the engine runs. Therefore I can rule out a bad carburetor as I know the 4MV off the '72 is good ('72 will lay 15ft rubber in a 1st-2nd shift).
- Next, back to the fuel system.
- Dropped the fuel tank to remove the electric pump that this model has. Found none, the pump has been bypassed so there should be no fuel restrictions.
- Replaced tank, started over.
- Measured voltage at the HEI distributor with the engine off. Found 11.97v with engine off.
- Measured voltage at the HEI distributor with the engine on. Found 7.0v with the engine running.
- Removed the HEI distributor. Replaced it with a points-type distributor (A1-Cardone from Kragen PN#30-1835). Also put on Borg-Warner cap, rotor, A2120 one-piece point set. Also put on new spark plug wires (Autolite) and Accel shorty header plugs
- I peeled back the harness and found that the HEI plug had been placed onto the harness where the resistor wire was. The wire was a blue 14ga wire inline from the solenoid. I cut off the HEI plug and grafted on an 18ga section of wire and connected it to the positive terminal on the ignition coil.
- I connected the ground on the distributor to the negative terminal on the ignition coil.
- Fired up the motor and felt no difference. The 'wall' is still there.
- Went to Kragen and bought a carburetor-style fuel pressure gauge. Mounted the gauge inline with the fuel filter and ran 4 feet of fuel hose with the gauge up and stuck it under the wiper. Ran the engine in different rev ranges under different loads. Found the engine would never get more than 6psi and the sputtering resulted in drops in fuel pressure down to just under 5psi.

I'm confused. I've changed 'everything' and still there is no change in how the engine runs. Help! A link to my post over on V8Monza.com follows and will give you more in-depth technical specs. I really need help here

http://pub52.ezboard.com/fv8hbodytal...cID=1988.topic

Thanks,
Colin

[GMC Jim]

if the resistor wire is "fried" then that will create an 'Open" in the wire; so; there will be no continuity. And no voltage will appear at the coil. the purpose of the resistor wire is to lower the voltage at the coil when the engine starts and is running....If I recall, during starting a full 12 volts is applied to the coil during starting only to assist in obtaing maximum spark during the starting period .
As you have 7 volts at the coil when the engine is running; then the resistor wire is not ' fried" and appears to have normal voltage ......... Jim

[lukecp]

7 volts wasn't cutting it for your HEI. They need 12 to run good, period. That may be a source for your problem. I'm not sure if i read your post right, but if i were you, i would stab the HEI back in there, and do a little wiring.

You are working on a car, and i'm familliar with trucks, but you need to run a 12-14 guage wire from the "IGN UNFUSED" terminal on the fusebox directly to the "BATT" terminal on the HEI distributor. If you don't have a IGN UNFUSED terminal, probe around in your fuse block until you find a terminal that is only active when you turn the ignition switch to the on position. You may want to install an inline fuse on the wire too. The wire will give you all of the power your HEI needs to run correctly. Go ahead and check it though to make sure you have 12v. I would not be suprised if that was your problem. 7v to your HEI is only giving it 58% of its needed voltage.

[ColinOpseth]

I'm scanning a picture from a service manual right now. Basically, it shows two wires going to the coil. One is the wire from the solenoid, the other is a wire from the switch.

I only have the wire from the solenoid going to the positive on the coil. Would this cause the problem I'm experiencing?
Thanks,
Colin

[ColinOpseth]

Thanks for the quick replies, guys.

I want to stay with points as I will be running an MSD 6AL soon. I'm wondering if maybe the wiring for this distributor isn't set up correctly?
Thanks,
Colin

[ColinOpseth]

Here's the wiring schematic I'm looking at.

[ColinOpseth]

Here is the schematic of how I have it setup now.

The light blue wire is what I have hooked up to my positive (+) on my coil. The dark blue wire is the wire running from distributor to negative on coil (-). The first schematic I scanned has a provision for the red highlighted wire. I'm assuming that's from the ignition switch?

Can I just run the distributor off the wire I have highlighted in dark blue or will I end up getting a progressively lower and lower voltage as the engine revs?

Thanks,
Colin

[ZOOMY]

If the resistance goes up, the voltage goes up. What you are probably thinking is that if the resistance goes up, the current goes down & that is correct.

[ColinOpseth]

thanks for the help ZOOMY,
Do you think that I have my distributor wired correctly? I'm not exactly Mr. Electricity, lol.. I'm wondering if a previous owner just decided to wire everything up this way and put in an inline resistance wire and go directly off the solenoid. I'm trying to find out if the coil will receive enough 'current' I guess you could say, running directly off the solenoid.

The wiring diagram on the bottom appears to have a coil wire coming from the solenoid (to prime the solenoid before cranking?) and then one from the switch (that provides juice to the coil when the switch is in the ON position?).

Again, I'm wondering if the way I have it now will work, or if I should just bypass all of this harness and run two wires correct (one from the solenoid to provide 12v and the second from the ignition switch with the resistor wire)..

thanks,
Colin

[GMC Jim]

I respectfully beg to differ .....Under the same load; as the resistance goes up ( increases) the voltage goes DOWN....Example; an electric brake controller has a sliding resistor to LOWER the voltage for less brake pressure....Also, a device is made called a dropping resistor to drop the voltage from 12 volts to 6 volts to use 6 volt accessories.....etc, etc.

[progress]

Points ingnitions have two wires as GMC Jim mentioned, 12 volt for starting and 9 v. for continuous running because 12 v. will cook the points (ask me how I know). Early trucks had a ballast resistor, later models had a resistance wire equivlaent to the ballast resistor. HEI needs 12 v. and a large 10 ga wire to carry all the current...running anything smaller or lower voltatge will be a problem with the HEI. Running 7 v. on your points may also be the problem. Try replacing the resistance wire with a new one to ensure you have a full 9 v. to the distributor during operation...12 v. when the starter is cranking.

It sounds like your resistance wire might have been over taxed during the operation with the HEI if they did not remove it. This could be the source of the problem in both cases...replace it and check the voltage again.

Good Luck

[73stepside]

points will run like an hei that doesn't have enough voltage. it will sputter and not have power. rplace that wire with a new resitor wire orrun new wire with a ballast resistor to keep it at 9 volts. you can run an hei with an msd ignition. it's just used as a refence signal, same as points. they have the wire harness for hei to run with msd.

[bpmcgee]

Originally posted by GMC Jim
I respectfully beg to differ .....Under the same load; as the resistance goes up ( increases) the voltage goes DOWN....Example; an electric brake controller has a sliding resistor to LOWER the voltage for less brake pressure....Also, a device is made called a dropping resistor to drop the voltage from 12 volts to 6 volts to use 6 volt accessories.....etc, etc.

I think you're both right. As resistance increases, the voltage DROP on that wire increases. Measured from one end of the resistor to the other, the voltage would go UP. Measured from the far end to ground, the voltage will go DOWN.

Now big group hug :p

Brian

[COBALT]

How's your intake??? I've had off-idle problems when fuel/air weren't mixing right down through the plenums. You might think about resealing it.

The 12/9v setup is essential. As long as you have a coil that can provide 9v you should be ok. There are actually two wires that run to the + side of the coil: both from the starter. There should be a wire that runs straight from the starter to the coil. The other one is actually 1/2 of a parallel circuit that comes from a fabric coated white wire from the harness above your firewall. It runs up from your starter to this wire (ignition), and then the other 1/2 runs down to the coil. The resister wire from the distributor runs to the - side of the coil, which you already know.

Try it with a new coil. I run an Accel superstack coil and I have ZERO problems.

[lukecp]

One other suggestion....

Assuming that all of the ignition system (whether points or HEI) checks out, and the fuel delivery system is fine, you may have internal engine trouble. Maybe a cam is going flat, bad or burnt vavles, or just about anything else could be causing that.

[71-longbed]

after cleaning my weights and springs....should i use some sort of lube on them ???

[beau396]

yes you always use lube on the distributor cam. That will keep the points from bouncing at higher revs. Also have you checked that you have 9v running with the points distributor? Did you set the point gap? Did you check the dwell angle? Check your timing? If all of these things are good try replacing your condensor and check that you have ground straps installed from the cylinder heads to the firewall, without them you can have some very strange electrical problems. Your cam timing could be off if your timing gear slipped a tooth, meaning you now have bad compression due to the fact that the valves would be opening and closing at the wrong time. So check your compression. Next look for vacumn leaks, especially intake manifold leaks.

[Long Knight]

I am no automotive elec. expert, however I strongly recommend getting rid of the points and slapping the HEI back in. If you want to keep the stock look get a Pertronix Ignitor. Points=Bad, Ele. Ign.=good. Using points is like using a washboard and water ringer at a carwash to do your laundry...ya, it's neat and time specific but it sucks. the modern method has no drawbacks, only advantages.

OK, the Beav needs to take a nap.

[FrankHoy]

I would also say that double checking the point gap/dwell would be critical. I have had similar problems with bad points &/or dwell setting, with rpms above 3000. Engine would idle fine and drive but when you tried to accelerate quickly the points would "float" out and lose almost all power.

[jhwkns]

I think yellow72custom has the right idea. You're describing the symptoms of a worn camshaft.