I’ve heard of this Lonestar curse but have not been plagued with it this year. My shop lost power last night due to a rodent chewing through the main line to the pole. Now to the car I have a 350 vortec, aftermarket dual plane intake Sean Murphy induction built quadrajet. Starts easy, idles smooth. I had maybe driven it 20 miles since getting together and then I started developing a exhaust back fire problem. So rechecked Timing good, 19-20 vacuum, 800rpm. I have AC Delco added fuel pump in a regulator at five psi. That help some I have it narrowed down to 1800 to 2200 RPM or so. The distributor is a brand new summer HEI out of curiosity I pulled the cap and I thought the weights and the springs were really loose for stock set up distributor. I compared them to another distributor and they were much looser. Any ignition gurus please chime in. Sent from my iPhone using The H.A.M.B. mobile app
I have never had a problem with the GM HEI units, but know that the module is normally the first place to look when you have a problem with an existing system. Normally, a faulty module will cause hard starting. The other obvious thing with any new installation, is check the connections. Sometimes an intermittent ground or faulty connection can drive a person nuts. I don't think my last suggestion is the problem here, but could you have water in the gas? Water will cause a carburettor system to backfire. Adding some rubbing alcohol to the tank will solve this problem. Bob
The car has sat most of the winter and there is a little bit of gas left in it but I drove it till it was almost out and just added about 10 gallons of non-ethanol gas Sent from my iPhone using The H.A.M.B. mobile app
I had maybe 10 miles on my '31 and developed a misfire at 2000 rpm and got progressively worse. Replaced the HEI module and life was good again.
I would drop in the other said distributor an rule out... Quality in this day/age is... Well pretty hit/miss... Even when new
Probably not the problem your dealing with now but it's good to store them with a full tank so that you don't get condensation build up in the winter with warm /cold cycles plus they say [not sure how true] that the fuel vapors are worse for your metal tank than the actual fuel is. May not hurt to throw in some stp gas treatment in case their is water.
Just adding non ethanol gas will not clear the water out of the carb. You need to add a product that will break the surface tension of the water in the carb, because the water will block the jets. Bob
I agree the module is suspect for what you are describing. The lower tension springs on the advance weights just allows the timing to advance quicker. That is a different problem than misfire.
Even on the low mileage unit check the leads on the pickup coil. Everytime the plate gets moved by the advance they flex just a tad and I've seen several that broke right at the end and were held on by the plastic insulation. My personal experience with modules is that they work or don't work and I have never knowingly seen one gradually degrade. Usually another ignition system issue is what blows the module. If I had a same style distributor sitting on the shelf that I had run before and knew was reasonably good and reliable I'd have them changed out and go from there. Tear into that one after you get back from Lonestar.
In my particular case, the module is not in the distributor. I built a hybrid Duraspark/HEI ignition for my SBF and the module is mounted to a HUGE heatsink under the dash. No flex, no heat, just a progressively worse misfire that replacement fixed.
To comment on the "looseness" that David is concerned about... By what you are doing to the advance weights, I assume...you are concerned about the "weights looseness". That should not be a problem, as all that does is let the mechanical advance go to full advance, faster than stock springs would allow. Overall, that's a good thing when all is right. As others note, either the module or the coil around the shaft could be bad (I've had both fail over the years. Even new things fail sometimes. Mike
Boy, I sure have seen one go bad gradually... almost got me a divorce (got one later anyway, but for other reasons... LOL!). Had a OT car that my then-wife drove and she started having issues with it misfiring briefly then quitting. And it wouldn't do it every day either, seemed to be totally random. She'd call, tell me where she broke down, I'd go there and the car would start right up and run fine. She didn't want to drive it, I'd switch vehicles with her for a couple of days and it wouldn't miss a beat, give it back to her and it would start dying again. This went on for weeks until she flat-out refused to drive it anymore. After two weeks, it finally died on me, bad module. After it cooled, worked again and passed all tests for checking the module; but didn't pass until it cooled.... They say cars have no feelings, but that car hated her; she was always having 'issues' with one thing or another, after I replaced it with another (this is after the ignition fiasco) and drove it myself it remained reliable right up until I sold it...
When I look at the first photo I see discoloration on the advance weights that is probably fine metal from wear. If it is metal, it is conductive. If it finds its way to the cap it can cause a trace arc to an adjacent plug. Look at the underside of the cap. Long distance troubleshooting is tough Good luck wood rats can make ones life hell
Call me paranoid but I carry an entire HEI distributor and a spare module in case someone else needs on. I try and buy any older factory modules when cruising the local Pik-n-Pay, they are better quality than the new stuff.
My first thoughts on the weights was it was advancing too fast for a stock motor. I changed out the module at hotel parking lot, trailering it down, ugh. It seemed to help some and I drove it into the show and back along with top notch friday night but still doing it. I did notice something it does it less when the motor is cool. Coil perhaps? Never had an HEI coil go sort of bad matter of fact the most I've ever had go wrong with these is a dead module.
All I ever had was the module going bad or burning a hole in the center of the rotor. Belair beat me to it. LOL. Lippy
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