i gotta 64 impala ss and after driving it around for about a week i keep having to adjust the timing to fix the idle, any ideas why it keeps doin this? could it be the distributor rubbing against the firewall and moving around? any ideas?
the timing comes early and the dwell stays the same.
Check the rubbing block on the points:
Sometimes people don't grease the rubbing block, and it wears quickly, changing the dwell and timing.
Also, check the plate in the distributor for looseness.
I hope this helps.
RK
thanks, will do. it's a 350, 4 barrel, hooker header, gas guzzlin son of a bitch.
ps, do u paint?
If it's still the original points style dist. it may be time to pull it and have it completely rebuilt. The comment about lubing the rubbing block was a good one though. It's possible however that it is binding up internally and retarding itself as you drive, and only a rebuild can fix this. Also the advance mechanism may be sticking (either vacuum or centrifugal) basically you gotta take it out, pull it apart, and look at it.
Personally, unless this is a 100% original car, I'd be tempted to replace the distributor with an early 70's HEI unit just for no- maintenance reliable sparkingness.
nate
Mark the distributors position and check the marks next time it's causing you grief.
At least that way you'll know if it's physically moving or something internal is messed up.
Also check:
1) hold down bolt is tight 2) the vacuum line for the advance. It has to be hooked to "throttle vacuum" 3) side wear/play in the distributor hose where the inner shaft spins. (should be damn near none) 4) timing chain back lash (8 to 10 degrees max)When you "adjust the timing", is it actually changing from it's original setting, or are you changing it to compensate for another problem?!?!
You do not have to pull the distributor to check the mech/vac advances. Pull the rotor off and check the mechanical weights and springs. The weights and mechanism usually rust. WD 40 or CRC will take care off that. Vacuum pump for the vacuum advance.
If it's "binding" (not spinning free), and nothing is worn, you don't have to rebuild it. You can pull the distributor, knock the roll pin out of the drive gear and remove the gear and shim. Twist and pull the inner shaft up through the points side of the outer housing. Sometimes you need to take a can of carb cleaner and with the red hose spray it into the shaft/hosing to cut all the built up oil. Clean the shaft on a wire wheel and clean the hosing with the carb cleaner and a small, round long handled wire brush. (usually found in the plumbing dept)
If it is a distributor problem, and it doesn't need to be "O" riganal, then yes put an early HEI in it. Very easy change over! And much better. Most off the time you don't even have to change heat settings on the spark plugs. You will have to monitor them for awhile to see for sure.
I've seen impala's of that vintage with bad motor mounts that would allow the distributor to hit the firewall. However, it would break the cap, not change time.
For less then $100 you can buy a Petronix electronic ignition system for it. That will eliminate the points and you should never have that problem again. Of course, if your distributor is rubbing against the firewall then something is not right, perhaps it needs the engine and transmission mounts replaced.
cause of timing change). Maybe the centrifugal advance or vacuum advance is kicking in.
I agree, sounds like either the centrifugal advance or vacuum advance is pulling the plate around and it's not returning for some reason. Time to pull the dist. and have a look. If the shaft was binding in the bushings and turning the whole housing, the timing would be retarded not advanced.
If you just rap on the housing with a tool with a timing light on the engine, does the timing suddenly retard back to normal?
nate
Yes:
I do full restorati>> Check the rubbing block on the points:
On the outside chance the car still has original mounts even after an engine swap, it should have them replaced with the later version. At the very least, they should be checked in this case. The original '64 mounts would not retin the engine on it's mount if the mount failed. There was a recall campaign in the late 60's to add a safety strap from the lower to the upper portion of the left mount. The real cure was to replace the mount(s) with the later model item that had the plates designed to interlock. I would find it surprising if it still has the original mounts - not impossible.
Lugnut
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