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Discussion Starter · #1 ·
Hi all,
'05 VR just rebuilt after a deer accident. Besides a few messages I have to clear out (SRS and Brake Assist) everything is running great. One thing I did notice and am wondering if anyone else has seen this is, during a quick acceleration (not redlining or racing, but not babying it) at about 4500 RPM I get a massive shutter and bucking. As soon as I throw the clutch in and let off the gas it stops and idles out perfectly. Then I can put it back in gear and drive through it. It's not all the time and not in all the gears. I'm not quite sure where to start looking because it's so erratic. Everything in the fuel system has been replaced except for the injectors. Everything is stock on the car besides an R-Kelly Mod. Any suggestions???
Thanks,
Keith
 

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Power stutter is usually one or more coils going bad. As the boost goes up, spark voltage increases, coil fails, cylinder doesn't fire, boost drops, coil comes back online and the process repeats itself.

Usually happens at the peak of the torque curve as you have discovered since that is the place where max cylinder filling occurs.

Been there, done that. Problem baffled me for so long it caused me to change out most of my sensors years ago and even build a rig looking for boost leaks, but it was just dying coils all the time.
 

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Discussion Starter · #3 ·
Thanks stealthy. That thought crossed my mind, I'll start there.

Sent from my SM-G900V using Tapatalk
 

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The fuel pressure sensor on the rail was replaced?
 

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Never heard of a case of FPS causing the stutter either. If I was a gambling man, my $$$ is on the coils. Also check your plug gap, if they are getting big enough it could cause even a good coil to fail and cause the issue.
 

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OP's description sounds very much like my FPS issue. I have a CEL right now for P0089. My new FPS should arrive from FCP Euro some time today. My fuel pump and fuel level sending unit are both brand new. My coils and plugs are about 2 months old, and my fuel filter is about 3 months old. My symptoms are that sometimes, under hard acceleration, just over 4K RPM's the car bucks and it's as if fuel to the engine cuts out. If I let off and drive more gingerly, all seems well again. This doesn't happen all of the time though.

OP, your symptoms and mine sound similar but it would help if you had codes. My P0089 has random misfire codes along with it(P030*). I'm installing the new unit tomorrow as I have to get it done ASAP since I'm overdue for my smog and registration.
 

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Discussion Starter · #8 ·
Brothermatt that's the thing, I'm not throwing any codes related to this. Might be easier if I was.

Stealthy, I'll check gap tonight, thanks again.

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When I had the coil based power stutter, it wasn't even bad enough to generate a misfire code. At one point I even got desperate enough to take it to the dealer for a vida scan and seeing if they could figure it out but it stumped them too.
 

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I was thinking that the FPS was the issue, then it seems more like the amount of spark getting to the cylinder may be the culprit. I'd say that it is probably rooted in one of two areas: either the coils / plugs are failing, or you have a fuel sending issue from the PEM (or FPCM, whoever you talk to uses a different acronym). I just replaced my PEM for a P0088 issue on my 2004 S60R, because they're notorious for failing because of where they're located.
 

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Discussion Starter · #11 ·
I just had the same code rockster. Fixed it with a new pem, there is a mod to move it inside. I'll do that soon.

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