Stutter on acceleration and hard to start
Thread Starter
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2nd Gear
Joined: Nov 2016
Posts: 61
Likes: 0
From: Chicago, IL
Stutter on acceleration and hard to start
Hi all,
So close to finally fixing all the problems on my car, this is (hopefully) the last one.
Recently, my '04 Cooper S with 130K has been taking a little bit longer to start, but cold mornings or it having sat for a while don't seem to make much of a noticeable difference. It's never not started though, just chugs a little while longer from time to time.
The other symptom that is more worrying is a engine stutter when accelerating with moderate throttle. I first noticed it in 6th gear, close to WOT. But now it seems to do it in other gears, maybe around 3000-3500 RPM.
I just changed the spark plugs, they helped with an occasional chugging at idle. No vacuum leaks that I'm aware of. I have occasionally gotten P0171 - System too lean codes about a month or so ago, but the stutter symptoms were never apparent. I cleared the codes to see if they would come back, and they haven't since.
Any ideas? My guesses are something related to the fuel system, but replacing injectors and such starts to get pricey. Thinking back, I don't think I noticed this until after I changed my spark plugs, maybe I'll try changing back to the old ones and see if that fixes things.
So close to finally fixing all the problems on my car, this is (hopefully) the last one.
Recently, my '04 Cooper S with 130K has been taking a little bit longer to start, but cold mornings or it having sat for a while don't seem to make much of a noticeable difference. It's never not started though, just chugs a little while longer from time to time.
The other symptom that is more worrying is a engine stutter when accelerating with moderate throttle. I first noticed it in 6th gear, close to WOT. But now it seems to do it in other gears, maybe around 3000-3500 RPM.
I just changed the spark plugs, they helped with an occasional chugging at idle. No vacuum leaks that I'm aware of. I have occasionally gotten P0171 - System too lean codes about a month or so ago, but the stutter symptoms were never apparent. I cleared the codes to see if they would come back, and they haven't since.
Any ideas? My guesses are something related to the fuel system, but replacing injectors and such starts to get pricey. Thinking back, I don't think I noticed this until after I changed my spark plugs, maybe I'll try changing back to the old ones and see if that fixes things.
OVERDRIVE
Joined: Mar 2013
Posts: 5,489
Likes: 629
From: Fuquay Varina, NC
The stutter could be the coil pack. My R53 did that at about that rev range. Pull the wires where they enter the coil, check the connection point for rust. If you replace, do not overtighten as you can crack the valve cover. And remember that the coil pack is held on with double rubber washers. The bottom ones are easy to get lost into the engine area when you remove. The upper ones are under the bolt.
Thread Starter
|
2nd Gear
Joined: Nov 2016
Posts: 61
Likes: 0
From: Chicago, IL
Battery is only a couple months old. Always put in 93 gas, or 91 if can't find 93.
Ah, good to know. I was wondering about maybe the plug wires too - was reading up on how to test those with a multimeter to see if they had gone bad.
Originally Posted by r53coop
The stutter could be the coil pack. My R53 did that at about that rev range. Pull the wires where they enter the coil, check the connection point for rust. If you replace, do not overtighten as you can crack the valve cover. And remember that the coil pack is held on with double rubber washers. The bottom ones are easy to get lost into the engine area when you remove. The upper ones are under the bolt.