So this recently started. I used to make my friends laugh by flooring the car at like 35mph in 6th, and having it not pull at all. Well, lately, if I lug it at all, or try to give it a decent amount of gas low in the rpm, it seems to stumble/misfire or something. No CEL. Higher rpm it pulls just great.

2004 6mt
60k
14k on engine
300miles on plugs(going to check plug wires soon)
coils were replaced under warranty not sure how long ago
weather has been about 50-60 degrees

Thanks in advance. I'm thinking it might be a plug wire not all the way on, but I wanted to check. Thanks again.

 

BUMP - checked all the plug wires to the plugs, they all seem good. Even though I had the coils replaced under warranty around 30k I believe(my printout has disappeared), do the coils go bad often? Could that cause a miss only under low rpm load?

 

Probably the reason that your not getting any responses is because the things your checking are usually the first things that people recommend. Plugs, coils, wires. After that things become less casual.

 

Haha. Yeah. I'm about to go reset the ecu and go for a drive. Also, when it gets dark, even though it only misses under load, I'm going to look in the dark for spark jumping. If that doesn't show anything, I may hook up my scan tool(cheap one) and try to monitor the injector duty cycle and see if it can monitor the coils to see if anything looks irregular. Just seeing if anyone else has stumbled upon this.

 

Well we need more info. lately, if I lug it at all, or try to give it a decent amount of gas low in the rpm, it seems to stumble/misfire or something. No CEL. Higher rpm it pulls just great. What gear are you in and how fast are you going. Maybe you are just in the wrong gear.

 

So tonight I did both the odometer hold reset, and the 20 pumps of the brake reset, and went and drove it... still there. Looked under the hood at night for a spark jumping/sign of a bad wire, nothing, yet, I can't do that when it misses, because it only misses under load.

Go 25mph, put the car in 4th, floor it. It misses, stumbles, jumps a little. Cruising at 60mph, in 6th, floor it. Same thing, 5th at 60mph does it for a little while, yet 4th not at all, and 3rd hell no. Any ideas?

NOTE - I know I am lugging it, but it used to do this, and have no problems. It stumbles now, in everyday driving, where it shouldn't. I know how to drive the car, but when I don't want to rail it, and drive it like a grandma at times, it acts up, and I know its wrong.

 

So I put some seafoam in the tank today. No noticeable difference yet. I also went ahead and changed the oil since it was time. I usually run 2-stoke oil in the gas, yet haven't been lately. I have noticed that at withing a few hundred rpm of 5500 is when it goes away in both 2nd and 3rd.

I figured I'd seafoam it since I was at it though. I know you guys like the vids. Sorry they suck, taken by my buddies gf with her phone.

http://www.youtube.com/watch?v=8ffSDy4D-zg

http://www.youtube.com/watch?v=A7I-Qjjq8wI

 

So I thought my coils had been replaced. Checked the history I have printed out, and it doesn't look like it. I pulled my coils, one had some major discoloration and a little white on it, two were discolored spots, and one barely any. Pretty sure its coils. Gonna do them soon and let you all know what I find.

 

+ 1 year of suspense ...

So what happened?

 

Well I sold the car about 7 months ago. I did find the problem before it sold though. I went ahead and replaced the coils. It was still there. I tried other plug wires, and it still did it. I then was looking at it at night again, and I saw a spark jump. I pulled the rear plugs, and one had the slightest hairline crack in the porcelain of the plug, and it was jumping through that spot. I'm very careful with the plugs, especially when I put them in, so it was either cracked when I got it, or it cracked when I put it in, or it randomly cracked while in. Anyway, turned out to be that. Ran like a champ afterwards.