I knew the timing was bad when i bought my 81 camaro automatic, but after a gross display of power something happened and made it almost undrivable. it now backfires when just pooting down the road at 30 mph, stutters, revs up and down on it's own.

i checked the majority of the vacuum lines and found my pvc valve was barely hanging on for dear life, i pulled it out and found out it's just sitting there, nothing is really holding it in place, super loose. so that's one thing, isn't the pcv valve supposed to be at least tight enough that it won't just fall out? obvious answer to that question, i know.

but other than that, i couldn't find any other vacuum lines that are loose. and I have no idea how to check if my timing belt slipped and i don't really know what else could cause this. i've shamelessly abused this car plenty before and it's been rock solid till this happened, now i'm scared i can't even make it two blocks to the store when i go out, lol.

so with a budget of zero and a garage only full of the most basic tools, what can i check myself to at least narrow down the cause?

 

If you think it is a timing issue, first check the ignition timing with a timing light and adjust it. If it stull runs bad after the ignition timing is corrected, then you need to take a look at the camshaft timing, the timing chain could have stretched enough to allow it to jump one or more theet, possible if you revved the hell out of the engine. This will require removal of the front cover and inspecting the timing gears and chain.

Another possibility, is that you have damaged the valve train when you beat up on the poor thing. Beating up on a car does not make it faster.

 

I would also check under the valve covers and make sure the cam/lifters/rockers are working ok. I've even seen worn engines launch a pushrod through the end of a rocker arm before. Stock engines, especially with wear, can take only so much of a lead foot. If something in those lines happened, then the engine won't run very well on only seven cylinders.

 

Well, you don't mention the mileage but I know in 1981 they had a nylon covered aluminum timing gear on the camshaft (as on my '81 Corvette)

At around 90k mine had worn and eventually jumped (I'm guessing 5 teeth)

The damage was so bad that most of the drivetrain needed replacing

so my recommendation when buying any older used car is to change the timing chain....

cost you between $50 and $100 but way less than the $2200 it cost me to repair my '81 sbc

 

Doesn't sound good! Could be the factory chain, or the pushrods, or even cam lobes that went flat from lack of proper oil changes.
I doubt if you'll get through this without some sort of expenditures.

 

i had a similar problem with my 78, turns out it had no choke at all on the carb! make sure the choke and idler are adjusted correctly bc that gave me headaches, also check your cap+rotor to see if it is all burnt up under the wires

 

If you're lucky your dizzy just moved but it sure sounds like a jumped timing chain and a bunch of bent valves and pushrods.