OK i just put in a MSD 6a ignition, 8572 distributor, Blaster 2 coil and new plug wires.

Car ran good before all this.

It fired right and had a a smooth Idle, a littel fast but choke may have contributed to that. anyway as soon as i acellerate it will stall and backfire.

Is the timing too fast or slow? I just want to get it running enough to take it and have it tuned.

Thanks
Jim

 

Choke opening all the way?

Carb, or exhaust backfire?

Check the plugs?

 

when you buy a msd distributor it comes with a very slow advance curve which must be tuned to your engine! if you installed the distributor without curving the distributor that may be the problem

 

I wonder if you're getting a lean stumble when you tip in the throttle ?

 

My car was doing something similar. Sounds stupid, but I finally realized that my divorced choke wasn't working any longer, so I was basically driving with the choke on the whole time. I didn't notice it just putting around, but I could feel the difference under hard acceleration.

 

Let me also say for clarification that it also does the same thing in the driveway when I rev the engine.

The neighbor even asked me (in a nice way ) when I was going to get me $hity $hity Bang Bang finished because he feeds the birds and they are not around anymore …. It pops so loud all the birds fly out of the trees and don’t come back….

So I went to the local speed shop and picked up some parts and during a round table discussion there with the locals they mentioned I didn’t need the vacuum advance on there and I should lock it out. So that is a project for tomorrow.

I’ll keep this thread updated when I know more.

Jim

 

I took off the vacuum advance tube and no Bang....Now i just have to get it tuned.

 

typical response from peple that have no clue what the vacuum system is for, how it works, or why it's there.
You think Chevy put the vacuum system on millions of motors because they just got a "deal" on vacuum cans from a vendor??!!

The vacuum advance system works together with the centrifigal advance. They are seperate systems but they work together to control the correct amount of spark advance.
A motor needs different amounts of spark advance depending on whether the fuel/air mixture is lean or rich. This constantly changes while you drive the car. At idle or steady cruising down the road the mixture is lean and takes longer to burn therefore needs more spark advance but when you accelerate the mixture immediately becomes rick, is easier to burn, so you don't require as much spark advance.
The vacuum system runs off manifold vacuum so can sense these changes and react to them and therefore make changes to the timing so the motor runs the most efficiently.
At idle, steady cruising, etc when the mixture is lean there is a lot of vacuum so the vacuum advance is advancing the spark. When the motor is under load and the mixture is rich there is very little or no vacuum in the system and the vaccum advance is not present therefore not adding to the centrifigal timing and lowering the spark advance.

Can you run a motor without the vacuum system hooked up? Yes you can but you are losing a lot and the motor will not perform as well or run as efficiently as it should.

My advice is to NOT listen to those idiots and self-proclaimed experts at your local speed shop and disable the vacuum system. Do some reading and learn about timing and the vacuum system and you can set the timing properly yourself.
If you don't already have them, go to your local sears and pick up a few pieces of equipment - it will probably cost you not more than approx $100 which is most likely what you would spend taking the car to a shop to get it tuned and you can learn how to do it yourself and I can almost guarantee you would do a better job than 95% of the local mechanics you coulld take the car would do.
Pick up a dial-back timing light (approx $69), a dwell meter, and a vacuum gauge. Also, pick up a distributor wrench which is used to lossen and tighten up the hold down bolt on the distributor.
With these items you will be able to properly set the timing on your car and also the correct mixture setting on the carb.


I learned how to do this stuff less than a year ago for the very simple reason that I went thru a number of local mechanics and realized not a single one of them knew how to PROPERLY work on older cars and older points type distributors.

To learn all about timing, advance, and how to properly set them up, there are two "must read" tech articles. These articles will greatly help you understand the "mystery" of timing and advance and will also take you step-by-step thru setting your timing properly.
They are both by JohnZ here on the forum and he generously allows me to host them on my website tech articles page.
Download and read them and you will learn a lot and no longer be dependent on local mechanics to do something that you can easily do yourself.

My tech articles page is here: TECH ARTICLES
The two articles you want are called:
Timing101Article.pdf
MAPPING ADVANCE.pdf

if you RIGHT CLICK on the file name of the articles you can download them to your own computer.

You may find other helpful articles on there also

 

This is all great information and will read as much as i can, but i don't just can't read papers and wing it and say I'm good to go.

I do have everything needed for tuning.....advance timing light, vacuum gauge..etc. But I just lack knowledge on setting timing with MSD ignition system setup to make it happen. I have a remote clue on setting timing with this setup but that about it. I have offered money several times for someone to come over and help me set this up but this is california and you don't get much help out here. I did get an offer but it was $80 for me to bring the car in and to tell me I have a problem and then it would be up to $300 to set it up for me..... that's not going to fly. So for now it will sit in my driveway.

Jim

 

When I had this problem about a week ago, the guy dyno testing my car told me it was my MSD 6AL box that was fried and causing these problems. He replaced the MSD box with an MSD module in the distributor and it runs 10X better than it ever has. Hope this helps.