Help - hesitation/bucking in higher gears

[Alladin]

Reading into this thread, it sounds like there are several issues that some of you are identifying as the same thing. It definitely can be a number of issues, and it's hard to identify things when people are throwing out suggestions that may not be relevant to the problem.

As a suggestion, start with the simple things. Get a tank of gas from a good gas station, run some sort of fuel treatment through. Next, check your connections on the intake side of the turbo, make sure there are no boost leaks. If that still isn't working, head to the dealer.

I have had the tank drained and ran Seafoam in the car a few tanks ago and the issue is still there. I haven't checked the hoses but assume they are ok since the dealership replaced the turbo. Luckily I am still under warranty but it's getting frustrating now.

And for those of you who don't know. Mazda has changed their policy as of May 1st about paying for rentals while you get warranty work done. They are only covering 1 day now and if your car takes longer to fix you have to pay for the extra days. Of course I'm fighting this as well.

 

[Super Shredder]

find someone with an aftermarket bpv or bov and do a switcheroo for a day. thats my advice.

 

[Blendercloud]

And for those of you who don't know. Mazda has changed their policy as of May 1st about paying for rentals while you get warranty work done. They are only covering 1 day now and if your car takes longer to fix you have to pay for the extra days. Of course I'm fighting this as well.

If the car was sold to you with the warranty and stipulations that you would not have to pay for rentals, you should be grandfathered in against that new policy.

 

[Alladin]

If the car was sold to you with the warranty and stipulations that you would not have to pay for rentals, you should be grandfathered in against that new policy.

I will check on that.

While I have been waiting for the dealership to get back to me, this weekend I tried too duplicate the problem and it never happened again. Of course I still have the issue of less power when I'm at full throttle vs half throttle. If get on it in gears 3-6 I notice alot more power at around half throttle.

Anyone know what this could be?

 

[Blendercloud]

Maybe a bad mass air flow sensor? Have you checked the spark plugs recently? They could be fouled also.

It just seems like one of two things:
A) you're not getting enough air into the cylinders (MAF sensor) to compensate for the extra fuel at WOT.
-or-
B) you're not burning all the fuel that is being delivered at WOT because of a fouled plug issue.


Have you been using any fuel additives like octane booster, injector cleaner, etc? Also, do you have access to tools? The spark plugs are under the intercooler. The intercooler is 3 bolts and 2 hose clamps to take off (really easy). If you can pull off the intercooler and pull out your spark plugs to show me some pictures, I could probably help.

 

[Alladin]

I changed my plugs about 2 months ago to NGK 1 step colder to try and resolve the issues. I still have the old plugs and can get a pic tonight.

They have a weird white film over the whole plug, even my co worker was laughing about how they looked.

I haven't used and additives except seafoam about a month ago to see if that would help.

 

[Blendercloud]

Are they Iridium plugs? Also, what did you gap them to?

When I went to a Denso Iridium one step colder plug, I gapped them at stock specs not knowing any better. I had some pretty wicked hesitation, bucking, and power loss. I pulled the plugs and regapped them from .032 to .028. It solved a lot of problems.

It's at least something to check. I understand you've had this problem since before the plug change, but it makes me wonder if you weren't dealing with fouled plugs causing a problem only to swap them out for a plug that is gapped too wide.

Check out the below link and let me know if your old plugs looked like any of these: http://www.theultralightplace.com/sparkplugs.htm

Also, it might be a good idea to check the gap of the ones installed. hope this helps!

 

[Alladin]

I remember seeing that site before and my plugs don't look like any of those.

I bought the 1 step colder Iridium NGK and I believe they are gapped too .44 which I was concerned about when I installed them. But I figured that's what people are running since you can't re-gap iridium plugs. I was thinking about going back to stock plugs but am afraid of spending $50 at a time to fix a problem.

One note, when I installed these plugs I didn't notice any difference in the way the car drove. If the gap is too big, shouldn't the car react too it? Maybe I have had a plug problem all along.

I did feel a bit of a stutter when accelerating in gears 3-6 this weekend. I can't remember if that has always been there or not...lol

 

[tunersteve]

I remember seeing that site before and my plugs don't look like any of those.

I bought the 1 step colder Iridium NGK and I believe they are gapped too .44 which I was concerned about when I installed them. But I figured that's what people are running since you can't re-gap iridium plugs. I was thinking about going back to stock plugs but am afraid of spending $50 at a time to fix a problem.

One note, when I installed these plugs I didn't notice any difference in the way the car drove. If the gap is too big, shouldn't the car react too it? Maybe I have had a plug problem all along.

Yikes! Way too large of a gap. Should be between .028 -.032. I would swap back to stock and get a set of Densos, that might solve your issue.

 

[Blendercloud]

Yikes! Way too large of a gap. Should be between .028 -.032. I would swap back to stock and get a set of Densos, that might solve your issue.

Steve's right in that the gap is way too large. You also don't want to be bending/regapping anything more than .008 from where they started. So you can really only go to .036 with those NGK's.

You can gap Iridium/Copper plugs, but you have to be careful with how you do it. You cannot leverage on the iridium electrode (the needle). They make feeler gauges that have a small leveraging fork to leverage the arm back and forth (in the case of Iridium and Copper plugs).

I would also recommend swapping out the NGK's for the Denso ITV22's. Gap them at .028. I know Autozone and Advance both have those special feeler gauges. They were like $6. It will be fantastic if you've only had a plug problem this whole time. I'd be thrilled for you. That's quite a weight off your shoulders.

 

[Alladin]

Like I said, I'm not sure what the gap was but I bought the NGK LTR7IX-11.

I guess I will go ahead and buy some more again and just get the regular NGK that are for this car. I just want the car running right again.

 

[Blendercloud]

Before you go with NGK, check what they come from the manufacturer gapped at.

Remember, you can only regap +/- .008.

 

[tunersteve]

Put your stock plugs (provided they're good) back in the car. See if the problem goes away. If it does, then decide whether to keep them or get ITV22s. They usually come pregapped at .030 (mine did) and you'll be all set.

 

[chiefmg]

This is the second post where I have seen someone talk about gapping plugs by prying against the center electrode. I know it was said not to do this to iridium plugs, but you should NEVER do that. My dad taught me to use the little tool on the feeler gauge to manipulate the side electode either way, you can also gently tap it closer on a hard surface if the gap is too large. I know not everyone has mechanical experience, but some things to me seem to be common sense.

I recently changed to the Denso ITV22 gapped at 0.030". Car feels stronger all around. I am not sure where the 0.044" measurement came from originally, if you look at the owner's manual it tells you 0.028-0.031". Maybe that is for normal 6s?

 

[Alladin]

Well here is a pic of one of my plugs. All four of them looked like this. These are what was in the car before I cahnged them and they are NGK's. I checked the gap and it's at .30

I only have 29k miles on the car right now

 

[Blendercloud]

The pictures you posted are representative of a plug with 15-20k miles of normal use and no neglect. You could probably get another 15-20k miles of normal use out of those relatively easily.

 

[Alladin]

Argh! Not what I wanted to hear. But thanks Bendercloud

 

[Dr. D]

i didnt read the entire thread but what i did read was that you have a problem with bucking in higher gears which could be your car reacting to knock... serious knock. or fuel cut. it wouldnt be a bad idea to invest some money into something you can log with (like the cobb AP) and see whats going on while the simptum is happeneing.

 

[Dr. D]

im not starting a fight but i dont think the plugs are to blame b/c i have had NGK's in my car for about 35.000 now. the only way i can see a problem with them is if they have a colder rating then stock. i would do some research on what you bought and then come back and let us know so we can come up with a solution for you.

 

[Alladin]

Well I put my old plugs back in and they are the NGK's. Can't remember the part number but they are not 1 step colder. The car hasn't been bucking for the past couple of weeks, maybe the dealer finally got that problem fixed. But I do still feel slight hesitations and bucking especially in 3rd gear.

Also I still have the problem with better acceleration at 1/2 throttle. I reset the ECU when I changed my plugs hoping that would help but I guess not.

I agree with data logging, but I don't think I should have to shell out that kind of money when the dealership should be able to resolve the issue.