Absolutely. Vacuum leaks are top priority. Look for snapped or deteriorated hoses per the diagram on your emissions catalyst. Your throttle shaft being loose can be a vacuum leak, and you'll need to have a bushing put in it if that's the case. You can simply wiggle it around without actuating the throttle to see if that's an issue. Electrical connections are important, too. A close inspection can be more telling than anything sometimes. A general test that people perform when singling out specific part for analysis is to unplug their power and see if the vehicle runs better. You can't really single any out, though, because the computer keeps an eye on all of them. I'd think you'd get something from the computer when these problems happen. Do you get an SES light at startup? If so, great. If not, then we're looking at a burnt bulb or a malfunctioning computer possibly. We won't go into that just yet. How does it idle? I'm assuming for the moment that this problem is only during acceleration and cruising. I've had ignition issues that play out just like this, but it could be a lean condition. I suppose even though the computer has a code for that, let's not completely rule it out. As far as timing goes, it is imperative that you have some sense of what it is at the least. If not by using a timing light to see the base timing on the harmonic balancer, then by using a vacuum gauge to see if you're reading too few inches of Mercury while having no vacuum leaks. One thing that I want you to double check is the Electronic Spark Timing bypass wire. Even though the computer should notice if it was unhooked, you should make sure it's nice and tight. Passenger side firewall single weatherpack connector. Sorry to throw so much at you, but this is a vague problem, which is answered with ambiguous tests and solutions until things start to narrow down.
