That's an old trick to sell you a new distributor. What they do is put a scope on it and point to the trace and say that the distributor has shot bearings which have uneven output and that's why the engine is running rough, and you can rebuild the distribtor, but it would be cheaper to put in a new one. Then if you fall for that they put in some cheap POS chinese junk which probably isn't even curved properly for your engine.
Just make sure to get the old distributor from them when you pick up the car, by law they are supposed to give it to you.
My guess at the problem is simply that the points condensor was shot. All this is, is a big electrolytic capacitor that keeps the points from arcing. These dry out as they age and when they get old, can fail with symptoms like yours. It's about a $3 part and usually in the older cars is in the distributor or on it's side.
Once the condensor fails the arcing of the points throws the timing all to hell because the current flow in the coil doesen't collapse immediately when the points open.
***That has happened many times in the past, for sure.
****Or the condensor develops a dead short because the electrolyte film is punctured. Since the condensor is installed ACROSS the breaker points, a shorted condensor kills the spark.
That's actually a plausible explanation, however. Worn lobes only exacerbate the problem, giving wildly varying dwell...
I agree.
Eh, maybe. Maybe worn out completely. Only way to tell is to examine it out of the car.
What I would do is try to find a local auto electrical shop that will work on distributors, and have your existing one, which you retrieved from the shop, rebuilt properly and swapped back into the car. Then you will have peace of mind that it's done right, and also a spare dist. on the shelf for emergencies (which shouldn't happen for another
Everyday the chickens show up at the Fox Den for their ritual abuse. Some people have money to burn, so no skin off my nose. I'll go there for warranty repair only, wherein I pay the first $100 deductible, but, after that, Fix Or Repair Daily picks up the rest of the $4,000 tab ;-\ Got in writing here, I do. But there's a catch to that too.
Last time I pulled that warranty trick with the dealership, they showed me a 75 penny piece of rubber hose that was leaking at the bottom of the radiator. They wanted $800 to replace the radiator. For a 75 cent piece of hose: "Nope, it only comes as one unit." they tried to tell me that when the rubber hose goes, the entire radiator needs to be replaced. ahhhhhhhh.............No.
MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.