["QUICK-SILVER"]

Originally Posted by jlwdvm

more info: Battery voltage engine off: 13.7
pertronix red lead engine off: 13.4
pertronix engin at idle: 16.53-16.8 (battery voltage the same)

NOT GOOD
Serious case of over charging.
Forget the timing problem for now.
Got to get the charging straightened out first or could end up with more problems.
Verify your voltmeter is accurate.
Don't run it no more than you have to.

May want to start a new thread.
Need to post lots of info; the car of course, wiring up-grades, alternator type, voltage regulator and type.

BE CAREFUL
Wires could burn
Battery could blow up

[jlwdvm]

The car is a 67 firebird, I haven't done much of anything to the wiring for the 5 years that I have had it. I removed part of the resistor wire going to the pertronix. I also repaired the ends of the 2 wires that go to the starter because they were a little ragged when I replaced the starter. The alternator is a replacement that I bought from NAPA a few years ago. It has an external voltage regulator that I haven't messed with. I do have a volt guage in the car that always reads 16-17 volts when driving for the last 2 years. When I was checking the voltage with my digital multimeter I had the dial set on 20V DC.

["QUICK-SILVER"]

Do you remember what happened when the volts went high or is that when you put the volt guage in?

You need to find someone or get your hands on an inductive pick-up amp meter. Volts that high, usually means amp out-put is maxed out. It could be the voltage regulator.
Check down a few threads, seems like, How to check a voltage regulator, it's not far down this page and covers a little bit about overcharging.

You should have been having problems with early battery failure, overcharging usually runs them dry.

Come back and let us know something, if you can't figure something out after reading that other thread.


It's just 4 threads down
http://forums.maxperformanceinc.com/...d.php?t=576463

[jlwdvm]

If I remember right, the way I have my volt guage hooked up is it is spliced into the light hot wire for the 3 guages I have. Like I said, I have basically been running the car with the volt guage reading 16-17 while driving since I hiiked the guage up. I replaced the battery this summer becuase it had been in the car for 4 years and didn't have a date stamped on it. I didn't know when it was going to give out. Like I said, the 326 ran fine before being pulled.

["QUICK-SILVER"]

Volt meter hooked to power wire for guages, no problem, same as OE on later models.

Check voltage on all terminals of the regulator, to see if it's a wiring problem, could be anything from a poor connection to a bad ground on the regulator itself.

Timing issue; how many degrees is it moving? Is idle changing at the same time?
If idle mixture goes lean, RPM's could increase and timing would go with it. When that happens, the added air flow, from RPM increase, pulls in more fuel and drops the RPM's and timing back down.
Same if idle mixture goes rich, operation just works the opposite way. Both cases vacuum will change, moving power piston.
Turns into a never ending cycle, up down, up down, up down.
Finer tuning of the carburetor, would be the cure, if this is whats happening.

How much free play is in the centrifical advance, before the weights start pulling on the springs? It doesn't take much at all for the timing to move quite a bit, even at 50 RPM idle speed change. Goes back to the first paragraph, timing changing fuel burn, causing slight RPM change, carb responds and it starts all over.

[jlwdvm]

I am definetlye suspecious of the carb. I recalibrated it according to Cliff's reccommendation to use recipe #3 in his book. I don't have much control with the idle mixture screws. I think it is running rich at idle, but even if I turn the idle way down with the curb idle screw and try to increase the idle using the mixture screws I don't get much response. I know the transition slots are fully exposed because I have to have the primary blades open so far to get the desired idle.
The timing issue is still present even if I turn the idle down to 650 rpm. The timing mark will bounce about 3/4-1" on either side of the "0" mark on the timing tab. Yes, timing fluctuation causes idle change as well. Carb and/or Electrical???????? Who knows??? More tests.

[jlwdvm]

I haven't had much time to mess with the car, but I did take a quick look at the voltage regulator this morning. It is very loosely attached to the rad support. What is the little cylinder shaped thing attached to the outside of the regulator with a wire comming out of it and into the regulator, and does a new one come with the new regulator?

["QUICK-SILVER"]

Originally Posted by jlwdvm

I haven't had much time to mess with the car, but I did take a quick look at the voltage regulator this morning. It is very loosely attached to the rad support. What is the little cylinder shaped thing attached to the outside of the regulator with a wire comming out of it and into the regulator, and does a new one
come with the new regulator?

Loose mount= poor ground and could cause overcharge. Wouldn't be surprised if the regulator wasn't damaged, contacts stuck or burnt inside.

The other thing is a radio capacitor. Will probably have to be purchased seperately. It does not have any effect on charging (meaning you can run without it), it does cut down on radio interference.

[PITTSBURGH 64]

If you still had the points you wouldn't be questioning this. That motor will not run any better with the conversion than a good working set of points.

I would put the points back in along with the stock advance springs....

[jlwdvm]

I picked up a new voltage regulator from Autozone and got it installed tightly to the rad support and cleaned the terminals on the wire harness. At idle the voltage now reads 14.23 at the battery and 13.9 going into the pertronix. Timing still bounces around, but it seems like there is a longer period of time between fluctuations now. I figured out that during the fluctuations the motor is loosing timing, then bouncing back to the 13 degrees BTDC. Could the long period of time that the car was overcharging have damaged the pertronix unit? I also took the carb off to recheck all the measurements for the new calibration.

["QUICK-SILVER"]

Over heating, from leaving the switch on with the engine off, causes damage. So does the wrong resistance on the coil. I would have to say that it's possible for over charging to hurt it.

You need to lock down the centrifical advance and check timing, use zip ties, rubber bands or something. You need to see if the idle, up and down, is moving the centrifical advance.

The leaky needle and seat has got to be repaired/replaced. Fuel level will not be stable, get too high, and will cause rich, unstable idle conditions.

I'm running a stock needle and seat in my quadrajet right now, on a fairly hot 400, turns 6500 + in every gear. Thats with mechanical and electric pusher pump, only need the pusher in high gear.

You've got to get fuel level under control and find out for sure on the centrifical advance, so you can get this thing figured out.

[BVR421]

see post #2

[78 GHOST]

I know this is gonna sound goofy..

Have you determined if you're suffering any kind of vacuum leak?

If you've got a vacuum leak, you'll find that over time you'll have to crank up the curb idle screw, getting away from the idle circuit. What will happen is the engine will smooth out as it gets more fuel, however you won't be able to control the idle, or control the idle mixture.

When your idle mixture screws don't have any effect, that is a clue you are no longer using the idle circuit when it should be in full authority.

If you know your throttle blades are open quite a bit, that is a clue you are no longer using the idle circuit.

IF you have a vacuum leak, you will be chasing your tail forever on all this other stuff and never cure the problem.

I'll wager this engine runs like a top when on the choke..

Is there any carbon tracking on the carb to manifold gasket? This is evidence of dirt and grime being sucked into the engine. Get a new gasket and use some pliable spray gasket maker.

Check your intake manifold and address any leaks you may find. It's not at all uncommon to find a manifold bolt (or a few) loose. Don't kill these things, tight is good.

BVR421 added a useful suggestion in recommending stiffer springs. Locking up the mechanical advance will certainly accelerate your troubleshooting time.

Keep in mind that loose springs will cause erratic timing and RPMs. The engine running at idle, not on the idle circuit will cause RPMs and apparently erratic timing.

P.S. The Pertronix LS1 needs that "warmup" time when first starting to saturate the coil. Personally, I think that is the dumbest thing.

[jlwdvm]

I put some stock springs in the distributor, but the curve was way too long, so I put a set of the stiffer crane springs in that start at 800 and all in at 3200. The timing at idle reacted the same with both springs. As far as the vacuum leak, I have looked for one and haven't found one. The carb acts rich at idle, so I would think that would mean that I don't have a leak. I tried to get the tip in at 2100 rpm set, but it acted rich even with the APT turned all the way in. I talked to Cliff and got a new set of custom rods and 73 jets to try. Carb is too rich at the moment. I talked about the idle screw characteristics with him. He said it is common to not have much input from the screws (as far as speeding up idle with only the screws) due to the characteristics of my xe274 cam. He recommended turning in the screws until idle gets rough, then turn out 1/2-1 turn with my 79 carb.

[jlwdvm]

So I finally got the carb back together (decided to have it plated) with the new jets and rods. Seems to be adjusted fine so far, but I haven't done tip-in yet. The timing still acts the same. Will bounce between 15 and about 17 BTDC with the idle also fluctuating between 880 and 920rpm. I would like to keep the idle around 900 because of the manual trans, but the springs in my kit for mech. advance start at 800 rpm at the latest. I tried the stock springs that pushed the curve way high, but the idle timing acted the same. Any thoughts?

["QUICK-SILVER"]

Something to try,
idle it up or idle it down, try one of the two or both. Just try for a stable idle and check timing.

Kind of back where you was to begin with. You've got to determine if carb or advance is causing fluctuations, or if one is causing the other.

Need to know if the timing movement is happening with the idle changes or if the two don't have anything to do with each other.

You need to see if there's any slack or loose movement in the centrifical advance. Also need to check for excessive distributor shaft endplay. Either could cause a 2° bounce.

Centrifical advance shouldn't be moving at all, while setting base timing.

[guccieng]

what about the distributor gear? hydraulic or roller cam (there are many problems with roller cams and 'melonized' gears)? timing chain loose? are you using a vacuum advance canister? how much vac at idle (you may be 'in and out' of the rated advance)?

[jlwdvm]

Thanks for the input. I was able to take the car out on New's Year eve for a 10 mile drive to get things loosened up. It was only about 15 degrees. A few things noticed: Car seems to "chug" when taking off from a dead stop or going from 1st to 2nd when driving casually; when accellerating slowly in second the car will start to "chug" when it hits 2100 rpm and then quickly smooth out; when it hits around 4800-5000rpm it starts to break up and I have to get out of it; when on fast idle at 1800rpm the timing still moves a little (probably the same 2 degrees). The motor is a fresh pro built 400, all internals new, #62 heads worked over, rebuilt distributor, comp cams HE 274 flat tappet cam, M20 4 speed, 3.55 ring and pinion. Hope this info helps.

["QUICK-SILVER"]

Smoothing out at 2100 makes sense. Basic RPM range on that cam is 1800 to 6000.
Anything below 1800 is going to feel sluggish and weak compared to stock.
That's one of the trade offs for the higher RPM power.

That said, your tuning may be about right.

Now you've got to find out what happened when you hit 4800. Might have had something to do with the cold temps. Like something trying to ice up. Try it again when it's a little warmer.

Keep us updated

[jlwdvm]

The last time I had the car out was probably the middle of October with milder temps. The motor wanted to do the same thing in the upper RPM range (would start to break up). Is there any way to test the Pertronix unit with a multimeter to see if it is good/bad? If it is toast due to running it at 17-18+ volts for a long time due to a bad volt meter what should I replace it with (not going back to points)?