WTF is wrong with my car?

[H-Town Speed]

Before anyone tells me to do search I already looked thru like 20 pages on fuel cut and hesitation and can't find exactly what I was looking for. This is my problem: today my fiance gets home from work(she took the car) and she's waiting for me outside to go out to dinner. So I pull out of my complex and get on it a bit in first gear(about 3/4 throttle and then when the rpms reach about 4k the cars starts to buck back and forth, it was real violent. It felt like if I was going from no throttle to full throttle. As soon as I let off the gas completely it went away. I tried to duplicate it and it does in second also, dunno about other gears. If I accelerate at light/part throttle it doesn't do it, only at like 3/4 to full throttle when I hit about 4k don't know the exact rpms. The car is bone stock down to the stock air filter and it has 11k miles and according to dealer it has already been flashed(service writer showed documentation during 7500 mile check up, though he could've been lying). It was about 80 degrees outside and it had just been raining earlier so it was humid as hell outside. What the hell is this and how do I fix it? Time to go to the Dealer?

 

[EVILSRT]

That is hesitation, when I got the flash it all went away.

 

[H-Town Speed]

Does the hesitation feel like the car has an on/off switch being flicked from on to off and back to on in rapid succession? If this is the case wasn't the flash supposed to alleviate this? Is it possible that the car wasn't flashed after all?

 

[wicked]

not necessarily,could be bad gas(but I doubt it) could be a waste gate malfuction,boost leak,but it sounds more like vacum leak.

 

[H-Town Speed]

I doubt it's bad gas, because when I left the restaurant I went straight to the gas station and gas it up to a 1/2 a tank(it was at a 1/4) with Shell 93 octane(this is the only gas I use) and it still did it. I'm planning on taking it in to the dealer tomorrow, just thought I'd try to figure out what it was before hand so that I don't get the run around from the dealer. Is there supposed to be a sticker on the car somewhere that says it's been flashed?

 

[wicked]

yeah there should be a sticker.
some have it under the hood,some in the door jams,some don't have a sticker.
Is there any one you know that has a msp in your area you can test drive to see if it's flashed?
either way the dealership should have record of the flash.have a print of all the work that's been done.they have to if you ask.
ask to have it re-flashed chances are they didn't flash it.

 

[H-Town Speed]

I don't know anyone around here to compare it to. I'll probably ask to have it reflashed. Maybe they didn't do it before. I bought the car in November 2003 so it should've already been flashed beforehand, but who knows. As for the wastegate malfunction, it could be cause I don't have a boost gauge so I don't know what I am boosting.

 

[GHOSTWHISPER]

sounds like a vaccum leak to me.

 

[DiscreetSpeed]

thats kinda normal man...the a/f ratio on the stock ecu is real bad and youll get bucking at partial throttle at certain rpm ranges when the fuel is about to flood the system as its tuned to do.

 

[DigitalHeadShot]

I would hope thats not normal. I got mine flashed and I get very little if any hesitation after flash. Befor the flash it was like rideing a bull, so I would look into re flash or take it in and make mazda fix the problem.. Here is a tip take the mazda tech with you on a test drive so YOU can make it buck. other wise they will drive around the building and say there is nothing wrong.

 

[H-Town Speed]

Discreet this was not at partial throttle it only happened at anything from 3/4 to full throttle and I sure hope that having the car lunge back and forth violently(read: very ******* violently) like you were goosing the throttle between no gas to fully punched and back and forth is not normal, cause then that sucks nuts. Dude let me tell you it was really embarassing, I felt like an idiot who couldn't drive stick. It kinda felt like I was bumping up against a real violent rev limiter(vvvrrrooommm..wa..wa..wa..wa..wa). Anyway I called the dealer this morning and it's schedule to go in tomorrow at 10 am. Gonna do the scheduled oil change, replace the two rear wheel locks(wheels locks and impacts don't mix) and get this problem looked at/fixed.

 

[ONRAILS]

Discreet this was not at partial throttle it only happened at anything from 3/4 to full throttle and I sure hope that having the car lunge back and forth violently(read: very ******* violently) like you were goosing the throttle between no gas to fully punched and back and forth is not normal, cause then that sucks nuts. Dude let me tell you it was really embarassing, I felt like an idiot who couldn't drive stick. It kinda felt like I was bumping up against a real violent rev limiter(vvvrrrooommm..wa..wa..wa..wa..wa). Anyway I called the dealer this morning and it's schedule to go in tomorrow at 10 am. Gonna do the scheduled oil change, replace the two rear wheel locks(wheels locks and impacts don't mix) and get this problem looked at/fixed.

haha... that sucks doesn't it? I didn't catch if you said you had any mods? One of the easiest things to eliminate that BS is installing the FCD. It not only prevents fuel cut when boosting more, but it will also smooth out the ride (tremendously). I went through the same thing...

 

[pip7441622]

Check all of your intake pipes, hoses and everything under there for leaks. I've had that happen in the past, the jerkiness (real harsh like) that is, and it was always caused by a leak somewhere.

 

[Rich24km]

Dude my car did this to me, and it felt like a fuel cut almost. I've felt it in other cars. But it was due to the fact that my intercooler pipe had come disconnected. It does it around 4000 rpms under boost. I was watching the gauge and no matter what boost level as soon as i hit 4000 rpm it would feel like i hit a wall. I tightened the coupling back down and it went away. maybe you're having the same problems.

 

[mazdaowner123]

Try resetting the ECU.

~brian

 

[DiscreetSpeed]

where are you at in houston?

 

[H-Town Speed]

Discreet read reply to other thread. However, wouldn't you fricken know it the damn problem just went away. This whole thing happened on monday. So I kept the car on Tuesday(fiance's daily driver) and I couldn't get the damn thing to do it again. Scheduled a trip to the dealer for today and today I still couldn't get the thing to do it. I guess on the one hand it's a good thing, but on the other hand it sucks because the dealer won't be able to reproduce. The service writer said that they would still look into it so that it's documented in case something happens to the car later on that's related to this incident. I was like uh.. ok, cool. So i'm sitting at home just waiting for a call from Carlos at Jeff Haas Mazda to tell me when I can pick her up.

 

[TheJohnny]

Mine does this as well and I've tried to tighten all the clamps, no help. Just something to deal with until I can totally upgrade the car, which will never happen, so I'm dealing with it.

 

[Teamzero]

H-Town...

Did your problem ever resurface? Just wondering as I had the same exact thing happen to me this morning. Definitely not the hesitation thing that everyone is talking about. It was the same violent bucking as you described. Car is also bone stock. I pulled over and reset the ECU. The rest of my hour trip to work was fine (flogged it in every gear just to make sure) but wondering if this is going to come back at me in the future.

-Thanks

 

[Aaron]

sounds like an intercooler pipe has partially come off, check all the pipes.