I bought my '92 RS with a 305 about a month ago, and have been chasing problems ever since.
It idles erratically, and I have done a full tuneup on it, replaced the ignition module, and rebuilt the valvebody. IAC valve is good.
It runs even worse when the MAP sensor vacuum line is connected.
I can tell that the intake manifold, valve covers and timing cover have been removed (red silicone visible).
How can I tell if some clown put in a more agressive cam without taking a bunch of stuff apart?
Thanks.

 

The easiest way would be to use a dial gauge to measure the lift at the lobes. That will at least give you some idea of whats in there. Basically this just requires removing a valve cover and a rocker arm on an intake and an exhaust.

 

That is what I was thinking of. If I find out that there is an aftermarket cam, will I have to take it out and get the grind number etc. to be able to have a tune made for me that will get the car to run right?

 

If you get a degree wheel, you can infer what the cam specs are from the dial gauge readings without having to remove it, assuming its an aftermarket cam. Youd probably also want to swap out the intake manifold and heads or work the heads over along with a better exhaust and other mods so you can take advantage of the cam. Id also just tune it yourself. Its confusing at first, but once you get the hang of it, tunings not too bad.

 

Yup, it has an aftermarket cam. I put a dial indicator on one of the spring retainers, turned the engine over, and the indicator read over .5". Now I just gotta find out how to properly tune it, and what kind of valvesprings to use.
Thanks guys, you saved me a lot of running around.