Car Stutters and pops, but only when hot
 

My car was recently, um, repaired. (see my gruesome forum welcome post lol) Once we fixed the problem, the car ran well for 2 or 3 days. I was super happy with my new found automotive prowess. The other day on the way to work (highway commuter) the car seemed a little sluggish at higher speeds, but only while accelerating. The next day, sluggish turned into little pops and sputters (seems like its almost fighting speed) and its all only under acceleration. Today while taking it back to the garage, I drove it slightly cold, as i was only idling a few blocks. It warmed for 5 minutes while I wiped of a pile of snow off it. As I was toying with the gas a little trying to recreate the sound as to display it to my co-wanna be mechanic, I noticed it was driving very well. I took the longer way over, and gave it some speed. It was doing great! We changed some crusty vac lines, and I took it for a spin. Since it sat, and was now cold, It drove well. I was dishing out some major back pats to us, but about 5 minutes into my drive the popping returned. I'm hoping typing out this big explanation with my findings may lead a more mechanical mind to point me to my bad sensor or whatever it might be. I've been short on time, and i checked the forums for items like this, but never found anything. I hope this isn't a re post. :crazysmile:

First thing I would do is test for vacuum leaks. Spray carb cleaner around all the vacuum lines and any place that could be a leak. If the RPM goes up, then you found a leak.

test your coils. my car had the exact same problem last month. if your coils are good have your ignition module tested, thats what fixed mine

Iv been giving that set of coils the evil eye since we have had starting issues sporadically. I been thinking bout hitting the wrecker since we have poured like.. way to much money into this car already, but its seriously cold here. The junk yard right now would be murder. Ever pull parts in -30c? lol I know its 2 nuts, but locating a coil pack that fits, looks good, and getting it might take a bit.I have seen a thread talking about multimeter testing your coils. Anyone got the link, or a quick answer?

Here it is.

https://www.gmforum.com/t278818/

Thank you to both Dans,
I tested the coils, and the middle one is dead. My uncle brought me a coil pack off a 3.3l V6 from a 93 cutlass, and I am wondering if this will do the job. They look exactly the same, but I am not 100% sure if it can/should be used. What i am trying to do is hold off on any more repairs till its nicer outside in a few months, but i don't wanna make things worse.
Any insight would be appreciated.

What I would do is test both primaries and secondarys and if they are the same, and the connections on the bottom are the same, it should be fine.

That's what I was hoping you would say Dan. I have the coils here, and I will check closer when I get home. Wish me luck! I seem to be needing a lot of it lately.

all the gm coil packs like that are the same for all vehicles. one of mine is off my old sunfire ;)

OK, The coils were the same, I swapped the screwy one for the replacement, and didn't do the rest of em (its -40c). My car had the same issues as it did running with the apparently dead coil. My new question is, if i changed the dead coil (the good ones read 4.6 i think) and swapped it with one that reads 5.8, could that cause issues? The whole rack of the set i picked up reads the exact same. this link https://www.gmforum.com/t244262/ leads me to believe mismatched coils are a bad thing. I am planning on switching the rest of the rack tomorrow morning, but i don't want to waste my time fixing nothing and freezing to do it.
Any insight into this would be greatly appreciated.