3500 rpm hesitation

[Ferrariferg]

I bought an 87 Fiero with a 4 cylinder a couple days ago and as soon as I got it on the freeway to bring it home I found that it has a hesitation around 3000-3500. It runs great until it reaches about 3000 then it sputters and shakes. Its almost like it has a rev-limiter. Sometimes it will settle down and and keep going as long as you take it VERY slow but most of the time it will just keep sputtering. I've only had the car a couple days so I haven't been able to do a tune up yet but I wanted to see what others had to say about it. My dad isn't much help with anything fuel injected and/or distributor-less. Any help is appreciated.

 

[Oreif]

Usually on the 4-cyl DIS engines the higher rpm sputter is a sign that a coil pack is going bad or a bad spark plug/wire. I would change the spark plugs and wires first. If it still sputters at that rpm, Then get a conductive timing light and hook it up to each cylinder and rev the engine. The timing light will flash. If you have a bad coil pack, When you rev it you'll see the flashes starting to have gaps/misses, The coil pack associated with that cylinder is the one going bad.

 

[Ferrariferg]

Is there a way to test the coil packs with a multimeter? I have a test light so I can do that today. The coil packs seem like they were put in a bad spot from the factory. I would think that having them on the side of the block would shorten their life from the heat. Maybe I'll relocate them if that turns out to be the problem.