mayhem052

So for about a week now my 79' has been idling lower than usual (about 600-700) usually it sticks around 800-900 but it has also had this strange surging problem where the rpms dip and come back up and continue to do this on idle, also the car tends to be very shaky when this is happening. On a particularly cold day I started the engine and it was excessively shaky so I turned it of and tried to restart it which usually alleviates the problem but it was not able to start up with out me revving to about 5000 while cranking and even then it was idling very low when it did have enough juice to stay alive. The battery is relatively new and I have very recently installed new spark plugs, wires, dizzy cap, coil, and had the oil changed about a month and a half ago and it was running fine until about a week ago although these symptoms only occur at idle and the car is just fine while driving. Is this something to worry about or is this pretty normal in cold weather? This is my first car which I adopted from my dad and I am totally in love with it and I love working on it but I have no idea what could be causing this as I am pretty new to this stuff.

J-cubZ

Is it Auto or 5sp? Might be the cold start valve. first check your spark pllugs and see if any of them have anything on them then check the injectors/connectors, fuel filter. check the connectors on the water temp and such, its a good idea to change all these connectors as they are most likely in bad condition. I fixed all of these things on my 79' and it fixed the prob. for me it was a combination of 2 bad injectors and all bad connectors. Hope this helps

mayhem052

Yes it is a 5sp, the injectors have been changed many times in the past I think last time we only needed 4 so its very possible the other two have started to go by now. I doubt it is the spark plugs as they have been changed so recently but I suppose it's always possible. It might be the connectors but I think the fuel injectors is the best bet. Thanks for the help! I like your Z's color btw .

PurePontiacKid

He was telling you to check your spark plugs, not to replace them, but to see how the car is running, be it lean, fat, or kosher...

My bet is you're running too rich now that it's gotten cold, and your AAV could also be out of adjustment. (mine did the same thing now that I deleted it)