Shudder when accelerating hard

[kevo26]

Heeey that sounds like what mine did the day it said I don't want to work anymore.

 

[mayaman]

I had this shuddering problem. I have frequent power loss occurring with my vehicle. The shuddering behavior began to appear during power loss. The check engine light eventually came on. I called up Mazda service, they fixed it. They said it was some kind of vaccum release valve that was getting stuck. The car still sucks though... I took out most of my mods because this thing keeps having to go to the shop.

 

[tunersteve]

I had the TSB performed today and I, as well as friends who ride in the car can tell, it does make a difference. Mine was simply reflashed, but it definitely did the job.

 

[mayaman]

Well, I'm getting the shuddering again. GODDAMN MAZDA!!! I don't even come close to driving this piece of s*** hard..

 

[wannabe]

Well, I'm getting the shuddering again. GODDAMN MAZDA!!! I don't even come close to driving this piece of s*** hard..

print out the TSB above and make sure they do that. when mine first did this over the winter, the replaced the valve, but it didn't fix the problem. it ended up being the o2 sensor, but i think the flash would help as well.

get the fixes and all will be good again.

 

[Alexander37]

I had a similar issue with mine with the hesitation and shudder. Took it in and the techline had the dealer re-program the car. Got it back and it stalled on me twice on the highway. Turned around, took it back, and was called today. The issue was the high pressure fuel pump. Part ordered, and hopefully will resolve. I had issues like this before, but it was that 2 of the coil packs had died. Once those were replaced it was great, but it did take 3 trips in before they could figure that out. The techline just had them reflash it, and replace swirl valve at first, and tried to say it was low grade gas. I have had more issues than most with mine, but as soon as it's diagnosed and returned, the car is just as quick as day one. Frustrating I know to keep taking it in, but hang in there.

 

[wannabe]

I had a similar issue with mine with the hesitation and shudder. Took it in and the techline had the dealer re-program the car. Got it back and it stalled on me twice on the highway. Turned around, took it back, and was called today. The issue was the high pressure fuel pump. Part ordered, and hopefully will resolve. I had issues like this before, but it was that 2 of the coil packs had died. Once those were replaced it was great, but it did take 3 trips in before they could figure that out. The techline just had them reflash it, and replace swirl valve at first, and tried to say it was low grade gas. I have had more issues than most with mine, but as soon as it's diagnosed and returned, the car is just as quick as day one. Frustrating I know to keep taking it in, but hang in there.

so after the flash it started stalling? did it do that before the flash at all?

 

[Alexander37]

No, the flash wasn't done this last time (to my knowledge). My diagnostics had errors around misfires and something else. I had my flash done the first time I took it in for the shudder about 6 months or so ago. It turned out to be the coil packs (after 3 trips in) were faulty. The same problem seemed to have come back when I took it back in this time. My idle was really low and it did stall a few times and there was some shudder. The tech-line had the dealer just re-set all the computers ( I don't know, that may be just an additional flash) but as soon as I got it back, it did it again immediately. This time all the issues were stemming from a faulty high pressure fuel pump. I know a lot of people have said the flash has been bad, but honestly, I never really felt a huge difference. I posted a thread on Speed6 Bucking. I had a lot of good responses there to nail things down. Hope this helps.

 

[Alexander37]

Got my car back this morning, and what a difference! New fuel pump did the trick. Got in on the highway and opened it up, and WOW! I haven't felt the car run this pure since I bought it. I tried keeping up with a Porsche this morning (bad idea I know, I got smoked), but the car responded very well, and all shudder and idle issues are gone. Fingers crossed it doesn't go back in anytime soon!

 

[chaunchy_sp6gt]

I'm kinda retarded when it come to the mechanics of the motor. Please bare with me.

A while back, my car sputtered, shuttered and what not around 2500-3000 rpm with load on it. Felt like fuel cut-off it was so herky-jerky. It threw the CEL and I was at a loss of 30% power. I took it in and they said a plug had fouled and there was alot of resistance on the wires (coil?)....They ended up replacing the plug and cable on the #2 cylander. Everything peachy again.

I notice now though that under the scenario that many of you have posted (6th gear passing 2500-3000rpm) I get a hesitation followed by a puff of extra lean exhaust cloud then zoom zoom. I always thought that was one of the quirks of the car, but perhaps this is a problem? This also happen in other gears if I'm lugging the motor a bit (3/4 throttle from 2000rpm). Does this any of this sound normal or is this the shutter problem everyone is speaking of? Because of this I just try not to lug the motor at all. I am aware that at WOT the motor tend to run pretty lean causing the initial smoke.....Is this not normal either?

Again, sorry about the long verbage and the lack of knowledge about how the car is suppose to work (I bought it with 10K and have no frame of refference). Under normal and slightly spirited driving, I have no problems. Only when I push it is when I'm concerned. Am I pushing too hard or does the car need to be serviced? The cloud of smoke every now and then following the hesitation concerns me a bit.

Any thoughts and opinions would be much appreciated.

V

 

[masskaos]

My studder is around 2.5k-3.0k rpms usually in 6th gear. I caught it once with my dash hawk and my knock sensor was going nuts. I was in 6th gear cruising and then pushed down the gas a little bit to accelerate. knock retard hits 6.3 and pulls ridiculous timing.

I have no idea what causes that but it scares the piss outta me.

 

[wannabe]

i had the dealer update the pcm on my car this morning. it seems to be a bit better, but only time will tell.

 

[Alexander37]

I am not sure what differences you guys have been feeling with the issues described, but I would like to also add that I have never had a CEL thrown for any of the hesitation or shudder issues. I have always been able to feel something wrong, but the car never said via CEL that I was right. Definately get the CEL's taken care of and go from there. If nothing works, then have them check some of the parts that we have had replaced. Like I had stated before, I had to take my car in 3 times and tell them to check the coil packs after reading another thread that posted similar issues before it was fixed as there were no CEL's at anytime.

 

[gooniac33]

mine has been doing this more and more lately. I was getting on the freeway yesterday and rolled into the gas to merge like I always do and all I got was clatter...... I need to take it in....

 

[ungrave]

What all you guys are describing is part throttle detonation exactly like I had.

I'm from the mazda 6 club forums, but I had to come here and let you guys know about the fuel pump TSB: http://www.o-m-g-w-t-f.com/stuff/Mazdaspeed6/01-022-08-1919b[1].pdf

This TSB has fixed both the studdering and powerloss problems that have been plaguing my car for the last year or so. Please note that the TSB has two parts. First is a ecu recalibration. They did this first on my car and it didn't help at all. I brought it back in and they preformed the fuel pump fix. THIS IS WHAT YOU NEED TO HAVE DONE! I had to take a test drive with the tech to show him that it was still studdering after the ecu calibration so be prepared for that. Everyone needs to go have this TSB done!

 

[mayaman]

Thanks for posting that quick grave, I will take it in and argue my point.

So I had a complete power loss the other day when accelerating but it was different from the shuddering. Its strange when it occurs too. Typically the car is very sketchy in performance, but on the good days, ie the days when it responds better, those are the days that tend to produce the severe throttle issues. Basically, I'll press on the gas and it will really start to take off so I'll give it a little more and then shuddering or complete power loss accompanied by strange clicking noises occur.

However on days when it seems to run with reduced power there are inconsistencies with the throttle but no complete cut off and or shuddering as mentioned above... Seems to be related to weather, it really likes the rainy days, might be that the mist off the highway, and or cool dense air cools off the intercooler and gets the engine running up to the point that the fuel pump can't keep up?? Honestly I have no clue why, all I know for sure about this car is that its my 3rd Mazda, and likely it will be my last. And at 28 I have many more cars to buy.

 

[Killer]

Mine is gone. I ran a Techro Fuel Treatment through a tank, then did an ECU reset. Its gone.

 

[ungrave]

Also wanted to mention that it took a couple hundred miles of driving on the updated fuel pump before the powerloss went away. I think it took time for the car to relearn the fuel curves with the updated pump. So don't expect instant results. Give it time to adjust.

 

[wannabe]

i had the ecu part done, and its still doing it occassionally. looks like the pump might need done eventually...

 

[elieleb1303]

hey guys about 2 weeks ago i put the su test pipe on my car, and last week i noticed it would studder a bit under acceleration. i figured it may have been from a boost leak i had, but today i installed a new cold pipe (due to a snapped bov bolt i couldnt get out) and when i was driving, i felt it studder in every gear while accelerating. my question is, if i take it to the dealership, should i take the tp off? i currently have the cat heat shield on it, but would it be smart to take it off?