[GregC]

Long story short, the cold makes my car run good, the heat makes it want to die. I've tried everything, but I think it may be that the mechanical advance isn't working. Would heat make the weights stick because of the expansion of the metal? The car usually seems to bog down when the throttle is full open, meaning the vaccuum advance is no longer working, correct? How would I test this, or what does anyone suggest?

 

[d1_bradley]

If you think its the advance just crank a bunch of timing into it and drive. It will buck and snort at low speeds but if the problem is no mechanical advance, this will tell you. The obvious way to check the mechanical is to remove the cap and see if the rotor will move and snap back by itself. Just get it good and hot and try it.

 

[GregC]

Thanks for the advice. I checked the rotor, and it's a little hard to turn it, and when you let it snap back, and goes a little slow, and never fully snaps back. What's my problem here? Do I need new springs, a good greasing, maybe a new distributor?

 

[d1_bradley]

May just need serviced. Pull the rotor off and clean good with brake cleaner then lube with a dot of white grease where the weights rub on the plate. I've seen people just blow WD40 on the assy, not too sure that's the way though.

 

[GregC]

Would new springs help at all? I greased and cleaned everything, but the car still acted the same way. The rotor still snaps back super slow after advancing it by hand. Could the springs not be backing the advance up enough , in turn causing the advance to be way too much for the RPM? It seems like when the bog down occurs, it's right when or right before the the tranny shifts. Doesn't the RPM drop at that point, requiring less advance?

 

[gnicholson]

Are you sure you dont have a fuel problem? Such as when the chokes closed car runs better.

 

[gnicholson]

You need to remove the dist. shaft to remove the adv. assy. to properly service the dist.

 

[GregC]

Ok, I'm a little scared. I decided just to check out how much the distributor that is recommended for this engine would cost. Turns out that having the wrong gear on the shaft of the dist may cause damage and voids the warranty. I will definitely be buying this distributor very soon. Does anyone know what kind of damage might occur? I'm guessing they are referring to the gear that locks into the oil pump??

 

[gnicholson]

they are talking about gear material such as bronze for steel roller cams or iron gears for flat tappet cams. What engine and dist. do you have? Sounds like you may have another problem. give me more info.

 

[GregC]

It's a steel roller cam...but I have no idea about the dist. It's a stock distributor from a 78 malibu with a 305. I have no idea what the material is. Know where I can find that out?

 

[gnicholson]

Unless your cam has been fitted with an iron gear when it was built you must run the softer gold colored bronze gear on your dist. You would have to change the one on your hei if it is the original in that case.Call up a company called Davis Unified Ignition.They can get you a dist. with the proper advance curve and parts for a hot spark; they specialize in hei's.They could also dial in yours.

 

[GregC]

Awesome, thanks for the info. Could this have been part of my problem with the engine running bad on hot days? I'm definitely going to change out the dist next week when I have time off for spring break. I was going to use my extra cash for headers and pipes, but I'd say getting the engine running right should be my first concern.