Backfire through carburator

[66vairguy]

Congrats on some good troubleshooting.

The vacuum advance moves the points plate on a pivot and there is a history of poor ground contact at the plate pivot. I recall Dale had a HD pivot fix. I always install a ground strap between the pivot and base plate. Just me.

BTW - The Pertronix module plate comes with a ground strap you add under the screws, but sometimes the strap is MISSING from the kit. I've fixed a couple intermittent Pertronix units by adding a ground strap that was missing.

[lerxst2112]

So, only a month into corvair ownership and I've learned A Lot! But I'm still not an expert!!! What gives?! I seem to be having a similar issue. Replaced points, condenser, cap and rotor, but still having a hell of a time. Timing seems close, but vacuum advance keeps getting stuck and when that happens engine chugs and wants to die. But when it's idling lots of misfiring and carburetor backfire when given throttle. It was better before I changed the points, I ordered another set to see if that helps. Pretty sure this thing has more issues than I can count but my question is about the electronic ignition distributor from CAcorvairs. Says it's pretty much plug and play. What are y'all's thoughts? It's a great price right now, or is it a get what you pay for scenario? I'm not trying to build a racecar, just want a running daily driver

[Wittsend]

1. Regarding the vacuum advance hanging up, are you sure it is on the proper ported vacuum (no vacuum at idle) and not on the manifold vacuum that would hold the vacuum advance on fully at idle (thus appearing stuck)?

2. If #1 checks out OK you should see some reason for the vacuum advance hanging up. Remove the distributor cap and apply vacuum to the advance and observe its travel. Hopefully that will give a clue. If you don't have one of those hand grip vacuum devices perhaps a length of hose attached to a near by running engine can be used. Of course there is also drawing vacuum with the mouth but usually the vacuum advance spring wins that battle.

3. Ideally there should be a short, flexible ground wire from the points to the distributor body to ensure proper grounding of the points. There is a chance that IF that wire is present it or its connectors are contacting the vacuum advance plate and causing it to hang up. In any case it is just good to have (when installed without interference).

4. Overall check the "wobble" in the distributor side to side (grab at the rotor mount and push/pull sideways). The bushing (if it needs replacement) is under $10 (less shipping) but requires disassembling the distributor and a means to drive out the old bushing and drive in the new bushing. It can be done with a hammer and a drift with minor skill. Just observe the depth that the bushing goes. I went too far and had to correct with compensating washers.

[SkidRo]

I have a "Stinger" distributor from Perfvair. The one you referenced looks very similar, if not the same one. It states that all the electronics are self-contained in the cap, which makes it very easy to install. At that price, that is a great deal. Just make sure you ask the vendor what coil to use. Mine must use a 3-ohm coil so it won't burn out. Anything less than 3 ohms will cause issues with over voltage.

Depending upon the cap type you may have to buy news spark plug wires so ask the vendor what it comes with and what wires to use.

I like mine. It works great; it is a brand-new distributor too so once it is in you will never need to replace the distributor again.

[lerxst2112]

@wittsend so I think no matter what I need to remove the distributor. The vacuum advance is swiveling around it only has one screw in it and it's moving all over the place. The advance engages and pulls it up and sticks. The points plate moves a fair amount to the point it's tough to even set the points to the correct gap so my thoughts were if I'm pulling I maybe just replace.