1984 Z28
305ci V8, carb
130,200mi

Car started idling lower than usual yesterday, around 500rpm which caused it to sorta shake like its going to stall but it doesn't. This is in park, neutral, and drive, everything btw. If I give it gas it seems fine and runs like a champ in top end so it doesn't seem to be missing or anything. The problem is only when I'm idle.

I took a poke around under the hood today after letting it sit all night and I think I found something disconnected from the throttle body but i'm not sure. Can anyone tell me what this is, if its disconnected, and if that could be the source of my problem?

pictures below:


I'm assuming the slotted piece connects over the nut on the throttle?


and if it helps, that cable runs to here

 

Yes, that slide bracket is off. It should go onto that stud and you should see either a hole for a pin, or a groove towards the end of the stud to pop on a horseshoe clip. It's for your cruise control, and it's possible that someone may have purposely popped the linkage off if the unit is locked up. Check to make sure the cable works freely before you reattach it, or it will prevent your throttle from moving. That would have nothing to do with your engine acting up though.

 

okay I understand now, thanks. So I suppose I shouldnt have to mess with that slider at all really...I dont even use cruise control. Do you think it would be a choke or carb issue? I know a fuel filter could be to blame as well, but I could be wrong.

 

oh, just too add. I replaced the catalytic converter two weeks ago. Again, no idea if thats any bearing on the engine performance or not. Please help =)

 

When is the last time it had a tune-up? Make sure your choke is working and opening all the way too. And if a fuel filter hasn't ever been changed, that wouldn't hurt either. But generally, if you have a clogged filter, it will be more evident at higher rpm's due to fuel demand being a lot greater. And is your air filter clean too?

 

Mine does the same **** dude lol. Mines same year also can I see some pictures of ur car? 1984 z28 305 H.O.

 

Its going to be due for another tune up soon but as of right now the air filter is clean.

Anyway, today I decided to take it over to the garage that installed my catalytic converter two weeks ago and their first guess without even touching the car was that the cat is bad already? They tried to warn me that a universal cat was a bad idea but the guy at Advance who sold me the Magnaflow assured me that they're all the same and universal only means it needs to be welded rather than bolted on.

I think this sounds a little far fetched that the new cat is malfunctioning already. I did a bit of research to find that these same symptoms of a rough idle often always point to a faulty oxygen sensor. Does this sound reasonable?

btw mesosneaky...heres a pic of the Zee