1999 Eclipse sounds like a popcorn machine

Hi all!

I just bought a 1999 Mitsubishi Eclipse RS 4 cyl 2.0L. I don't know what got me to buy it but I don't want to get rid of it. It is all sorts of trashy but now that I have it, might as well make into a nice project car right?

Well here's what I have as an issue right now... it misfires and stutters when accelerating. I took it to Advanced Auto Parts and got codes that say cylinders 2 and 3 are misfiring. I replaced the spark plugs with Autolites temporarily to see if that was the problem. I got a lot more power but it still misfires. I also found out that the previous owner was using a lower octane fuel to fill it up so I completely emptied out the gas tank and filled it up with premium fuel. Again runs even better but still sounds like a little popcorn machine. I bought some spark wires but haven't installed them yet due to the weather. I hate the snow. Another reason I haven't installed them yet is because one of the guys at Advanced Auto said that there could be a potential issue with the carburetor? That didn't sound at all right but what do I know. I am not exactly car smart at all. This is my second car, my previous one smashed to smithereens by some old woman. Anyways... opinions anyone?

I'm also using this forum as a 'gateway' to learn more about automotives. It's perfect for it seeing that there is noticeable electrical and possible engine issues. I got the car dirt cheap so why not right?

Anyways, Thanks in advance!!

Welcome to AF

It sounds like your off to a good start doing a few maintenance items to eliminate possible issues. Plugs and wires are a good start. Did the check engine light come back on once they cleared the codes? Sometimes its good to get them to clear the codes and then get them rechecked if it comes back on, some codes could be from previous problems that were never cleared.

I would start by checking the wiring going to the injectors and the coil pack. Especially around the EGR tube on the right side of the head. Does the car miss at idle or only under certain load conditions?

Welcome to AF

It sounds like your off to a good start doing a few maintenance items to eliminate possible issues. Plugs and wires are a good start. Did the check engine light come back on once they cleared the codes? Sometimes its good to get them to clear the codes and then get them rechecked if it comes back on, some codes could be from previous problems that were never cleared.

I would start by checking the wiring going to the injectors and the coil pack. Especially around the EGR tube on the right side of the head. Does the car miss at idle or only under certain load conditions?


I was actually going to see about the coil pack tomorrow. As for car missing, it misses when accelerating. And it doesnt catch speed at all well. I also think it has something to do with the horrible cold weather. Heh. We'll see tomorrow

And by the way the non turbo models do not need to run premium fuel. You are safe to run 87 octane

And by the way the non turbo models do not need to run premium fuel. You are safe to run 87 octane

Woot the popcorn is gone and my Eclipse doesn't lose power on the highway anymore! Turns out I kept getting bad wires until now. Now for the part that stumps me... apparently there are still misfires going. I don't feel or hear anything though. Not that I know much of it because I'm not exactly car smart... I reread your post because I remember you mentioning something else. Where and how would I check EGR tube and coil packs? As the for the misfires... my check engine light blinks when I idle at a stop. a friend of mine mention this might have to do with my AC compressor/ power steering belt. I removed it because my tensioner pulley fell completely off. Stripped bolt... my doing. I ordered a whole new tensioned assembly because why not replace the whole setup- the old tensioner assembly was slightly rusty (I live right on the coast). could that have anything to do with the idling? I have my doubts as it doesn't sound too logical to me...

The check engine light should only flash if there is a big problem that is currently occuring and needs attention, Im not even sure if the 420a ECU has this function, but I have been it on many other cars so its possible. Just something I havent seen before. The PS or AC belt wouldnt cause this issue. I would get the codes pulled and see what the problem is. At least you are making progress.

The check engine light should only flash if there is a big problem that is currently occuring and needs attention, Im not even sure if the 420a ECU has this function, but I have been it on many other cars so its possible. Just something I havent seen before. The PS or AC belt wouldnt cause this issue. I would get the codes pulled and see what the problem is. At least you are making progress.

Agreed on the progress, but now I'm a bit worried. It has been flashing since I got the Eclipse. whenever I do pull the codes all I get is misfires. I'm probably just going to have my mechanic take it for a couple of days and work something out. Will update when I can.

Hi again! Just an update.... the popcorn has stopped completely! I think it has something to do with the warm weather... anyways.. the popping only happens when I gas it around tight corners.

Here's the new concern of my car - not sure if I should just put this in another tag.. - again I am car illiterate, but here's my personal diagnosis. My Eclipse will now feel like there is grinding when taking off, and doesn't shift right. I've already caught crap about it, but my Eclipse is an automatic, and my personal diagnosis about the grinding is it has something to do with my transmission. One of my friends told me that stock automatic Eclipses receive transmissions that go to crap after about 60k miles. Well.... I just turned it to 164k literally this morning.

Anyways, that's my next issue I want to address. After that's figured out, I want to find out what the heck the previous owner did with the wiring in it... The stereo is definitely not wired to the ignition switch. Killed my battery once already. I just tore the stereo out until I can find out how to fix that... Again, car illiteracy is in me haha!

Thanks for the help!

what type of grinding does it make? haha two months late but hey, I just joined here. like where do you hear it the most?? <-- try changing trans fluids.. helps alot..

what type of grinding does it make? haha two months late but hey, I just joined here. like where do you hear it the most?? <-- try changing trans fluids.. helps alot..


Yea you need to investigate where the noise is coming from more. Open the hood and have someone walk beside the car while you drive it to try and narrow it down. I wouldnt change the tranny fluid in that car. With that many miles on the tranny its going to slip and die if you change it out.