Just rolled pat 20k KM's (12k miles or so). I notice the odd time when I'm on it a bit (3/4 throttle) sometimes the engine will cut out and the drivetrain will clunk fairly harshly.

It's not the traction control either (the light doesn't light up) and I honestly don't think there is any slippage plus the traction control isn't anywhere near this harsh.

Any ideas?

 

yepp.....misfire/detonation

 

Come to think of it - that is what it feels like (misfire). I wonder what the cause is because this happened on the stock ECU and I always run 91-92 octane (92 in the tank this time).

I can't imagine it would be detonating so bad to almost shut the engine down without throwing peices everywhere.

 

thats why, among other things, my mazda was bought back

shut down (as in the entire car shut off) on the highway, twice, me going 70, once on an offramp

be careful....i would check your recent mods....

rare case, could be a bad tank of gas...but just be careful

 

if on the stock ecu, maybe something was out of wack with the swap...?

 

It's odd because it only seems to happen in the same situation, but only once every couple days:

- Turning (like an arcing left turn).
- 2/3-3/4 throttle
- Only in first gear around 4500-5000 rpm (right before it shifts)
- WOT is no issue - though much more likely to get actual traction control involved.

I only ran the Hondata for a couple days, then went back to stock since my remote start stopped working (immobilizer) and it was winter. It's done this on a couple different tanks of gas. The ECU swap is pretty straight forward, the 3 connectors lock in place.

I really hate dealer visits for things like this - they will never be able to duplicate this.

 

i made the master tech take my car home and use it till it happened....i frankly didnt give 2 shits....i certainly did not want to be driving it...they threw the book at me in terms of things that i did to cause the detonation, mainly, they thought i was cheaping out and putting in less than 93 grade

so...i put the ball in their court, said ok, drain the f'ing tank, take the car to the gas station of your choice, fill it, ill pay...and then what?

so they did, and bang, detonation

depending on the severity of the misfire, you never know when your safety will be jeapordized...if it gets to a certain point, the computer will shut down the engine to protect the vehicle....

i may be the rare case...but trust me, nothing was more terrifying than getting off the highway going into an intersection with a dead car. i had to curb it to stop it. and then being in the middle lane of the highway, and bang, dead car

so i guess...u dont want to have something horrible happen, it wouldnt hurt to have them keep the car and maybe tell the tech, take the thing out over the course of a few days till it happens...because u hoenstly cant predict that if it happens again, it wont be worse etc....gotta get it looked at, could be something with the fuel pump as well, but i wouldnt judge the problem yet till its looked at

when it happens....do u get a check engine light or any caution etc??

 

No lights or anything. It cuts out for a split second, then recovers. No warning lights or anything. Runs strong WOT. It seems to happen right before the 1-2 shift like the ECU is doing something before the shift.

I'll keep an eye on it and hope...

 

the more u talk about it, the more it sounds less like a misfire, sounds more hesitation/gear related

 

To me, it feels like the engine dies first, then the clunk happens.

It hasn't happened enough for me to describe it that well. It's only happened 3-4 times and the first couple times wasn't that dramatic and surprised me - but it just felt like an over aggresive traction control (no lights though). The last time, there was a good clunk, but maybe it's the engine cutting out, then the trans thinks it's needs to shift, but the engine wakes back up and clunks.

 

hey, so whats going on with this?