: bad engine shake



72HearseGuy
07-18-12, 05:50 PM
When the car is idling the engine shakes pretty bad. When I give it some gas it seems fine.

72HearseGuy
07-18-12, 09:20 PM
The rest of the car doesnt shake so Im thinking the engine mounts are crap.

cadillac_al
07-20-12, 09:43 AM
I have seen some messed up carbs make an engine shake. If it is the carb it will probably get worse. Although you have a 72 with points so all bets are off. I always blame the points first.

72HearseGuy
07-20-12, 11:32 AM
I could try the points first cuz they're pretty cheap. Are they pretty easy to replace?

72HearseGuy
07-20-12, 11:43 AM
How badly will changing the points mess with the timing?

cadillac_al
07-21-12, 10:32 AM
I may have misunderstood your shaking. I was thinking of a bad shake like an out of balance washing machine. If yours is a mild shake and it runs pretty good.........it could still be the points; especially if you don't know when they were last changed. They do have to be adjusted so you either need some old guy to do it or read up some old manuals.

72HearseGuy
07-22-12, 03:17 AM
They looked pretty dirty, but the rotor and inside the cap were clean though. They're all cheap parts so I'm gonna do all three. My neighbor said hed help me adjust em. I'll report back when they're done.

72HearseGuy
07-22-12, 03:18 AM
The dist cap wasn't sitting snug cuz one of the spring clips was broken.

Bigger=Better
07-22-12, 10:18 PM
I had the same problem, turned out to be a worn throttle shaft bore in the carb base plate.
Even tiny play will allow additional air into the engine causing rough idle and/or stalling.
-> carb overhaul
You could also check torque on carb and intake manifold bolts.
Worn carb gaskets may cause leaks as well.

78cadillacfleetwood
08-20-12, 06:00 AM
my 78 fleetwood used to shake bad at idle until i made her suck back a can of seafoam threw the pcv valve and she is still fine right now