[locomotivebreath]

How long does a set of points last ?

[Kenth]

Recreational vehicles don´t get much miles a year, maybe 2000 miles if summer is good, but after 16 years i decided it was time to change the points in my 1966 GTO. They looked good for another few years of duty, i changed them anyhow.

[Cliff R]

With a stock coil and factory resistor wire they need to be looked at by the 20,000 mile mark if it still runs well and timing or dwell haven't moved.

Typically if the rubbing block was good and they hadn't required any adjustments I'd just double fold a piece of 600 grit auto body paper and smooth them up some and right back in service.

I'd add here that this only applies to good stuff, like Delco Remy OEM points sets, or the top end Mallory, Accell, High Grade Standard, etc.....

[kyle_blake]

And also don't leave your key in the ign position as I believe if the points happen to be land on each other current goes through them and it slowly burns them out??? i mean how much real ign on time does one really need to literally remove the contact pads so badly. I run a stereo in mine and i use to hang in garage and listen to it on ign. I did find the points ended up sorta diagonal but i had no reference point so now i don't leave ign on.

[64speed]

The knocking noise was paranoia. I think the box is bad cause I went thru all my wires and grounds and still nothing.

[triathlonx13]

Do you think you ever had detonation?
What kind of heads and valves?
Might try a leak down on your heads.

Had a problem with valve seats...

I tried all of the above - found out it was my valves seats on 2 of my valves.

Only other electrical thing I didn't see here is check your caps center carbon tip. Is it round or has it worn flat?

[Ram Air IV Jack]

Originally Posted by Cliff R

With a stock coil and factory resistor wire they need to be looked at by the 20,000 mile mark if it still runs well and timing or dwell haven't moved.

Typically if the rubbing block was good and they hadn't required any adjustments I'd just double fold a piece of 600 grit auto body paper and smooth them up some and right back in service.

I'd add here that this only applies to good stuff, like Delco Remy OEM points sets, or the top end Mallory, Accell, High Grade Standard, etc.....

We were big on the Sorenson X cut points back in the day. Good sets too and they lasted a long time! I bought several Delco D112P points years ago when they were pretty cheap but now will cost you a bit...

[grivera]

Originally Posted by 64speed

The knocking noise was paranoia. I think the box is bad cause I went thru all my wires and grounds and still nothing.

Did you visit the rev limiter as mentioned above and remove the RPM chip?

[HWYSTR455]

I vote wiring or a coil issue.


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[Lemans64]

Is the MSD box a Digital 6425? have heard of a few that would not rev, Mine did it a couple of times, seem to just not want to rev up.
But has only done it 2 times, local machine shop had one on the dyno with similar problems, would not rev past certain point,
they changed a bunch of stuff, then eventually changed out the box and was fine.

[64speed]

To the other helpful folks, it’s the digital 6425. Was running fine coming home and then it just intermittently started acting like it was hitting the rev limiter. Part throttle cruise was fine. Got home and did some testing with different RPM and found it started to break up around 3200 consistently and would NOT rev past 4000. There is no mechanical problem. I took the valve covers off and checked lash. Fuel bowls are staying full. 6-8 psi of fuel pressure.

[steve25]

First off did you do anything before this took place that could have got the firing order screwed up?


You mention of noise could be a cylinder firing when it should not be.

Where are you in the throttle at 4000 rpm where when it starts to screw up?

If it’s under part throttle then if you buzz the to 4K out of gear will it still screw up under that no load condition?

If so then put a timing light on it and see if the flash changes when it breaks up.

Also it might not be messing up on all cylinders, so put the light on all 8 cylinders.

If it does then you have nailed it down to bring a ignition related issue.

I have always kept a points dizzy with wires with me in the trunk and a easy way to hook it all back up for times like your having.

If you had such on hand this all could have been resolved by means of a 1/2 hour long swap over session and like 4 days ago now.

[HWYSTR455]

What coil are you running? That's important, because a coil going bad has some of the same symptoms you are describing.

When it's cold, does it break up? And then slowly start getting worse? Once it's run for some time, put your hand on the coil and see if its hot.

The LED on the box is supposed to 'flicker' while it's running:

"LED
The LED will flash for every trigger signal from the distributor or crank trigger. You can take advantage
of this when statically setting the timing when false triggering the box to troubleshoot. Also, when the
engine is not running, the LED will be On when the key is in the On position."

Instructions for the box:

https://static.summitracing.com/glob...5_frm29772.pdf

Make sure the coil is wired properly and the + and - wires are not swapped.

Check the rev limiter setting and function:

https://static.summitracing.com/glob...d-6425_add.pdf

If all that checks out, unplug the tach from the box. Some have experienced issues with certain tachs with CD boxes.

When seeking help, provide accurate & detailed info. Without that, it's easy for others to not provide proper troubleshooting paths. Pics help a lot.

Simple phrases like 'the box is messed up' is not helpful, and don't get stuck on one solution or cause. It adds to frustration.

If you start a troubleshooting thread, follow it through, and try to do so promptly. Have to understand, folks are doing this out of love of the hobby and generally want to help, but you have to help them help you. No one here is getting paid to help anyone.


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[64speed]

The only reason I haven’t gone and bought an HEI and taken off is because it runs soo good right now I really didn’t want to swap the distributor until I was sure. Today I am taking the box out of the equation and just gonna run it on the RTR and see if that cures it. I haven’t had time to mess with it so I have just been driving my truck.

[HWYSTR455]

Ok, RTR, I was assuming it was the billet standard, that requires a box. Again, please provide complete and detailed info.

Removing the box from the mix is a good test and easy.

How are you powering the distributor, from the factory coil wire? It needs to be a full 12+ volt feed wire.

Double check the mag feed wires, many times they are reversed and you have to switch them around.

https://static.summitracing.com/glob...50400-1_fc.pdf

"WHEN INSTALLING A HIGH PERFORMANCE IGNITION SYSTEM WITH THIS
DISTRIBUTOR, PLEASE REFER TO THE INSTRUCTIONS THAT COME WITH THE
IGNITION CONTROL BOX. THIS DISTRIBUTOR HAS THE CORRECT COLOR CODE
FOR WIRING.
 Black wire with Orange tracer = Positive (+)
 Black wire with Violet tracer = Negative (-)"

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[geeteeohguy]

Originally Posted by 60sstuff

Agree with Kenth.
I never understood why you would want to change from what the Pontiac Engineers designed to work most efficiently for these performance cars 🙄.

Have run stock GM points distributors in all my GTO's for the past 45+ years for 100's of thousands of miles without a hiccup. And running them now in the 3 GTO's and the old 'vette. No worries.

[64speed]

Coil tests good with OHM meter and the MSD box passes the startup light test. When I went to take the distributor cap to inspect the inside of the distributor I noticed that the cap and rotor are in horrible shape. I don’t know what would have caused that but I’m gonna change it and see what happens.

[HWYSTR455]

Ohm meter is not a good test, you have to put your hand on it after it's run for a while to check for overheating.

"Horrible", explain that or post a pic. Vague, non-descriptive symptoms are worthless for troubleshooting.

Can't help you without specific info. To us, you're just complaining. You've gotten plenty of advice here and you haven't confirmed if you've done the checks or gone over the basic, you switch gears from post to post. Follow through.



.

[grivera]

Dave - Any pictures? What do you mean horrible shape?

Mike - how hot is too hot for a coil - if it’s an oil filled they don’t run cool.

[64speed]

I will post a pic when I get home.