drseid

This morning, when starting my car (no problems), I backed out of my parking space, and started driving as normal (with no engine warm-up). I immediately noticed that when I hit the accelerator in first gear, the car seemed to hesitate...

I go about a tenth of a mile and slowed at a stop sign. Afterwards, I hit the accelerator to go forward, and for about a full second nothing happened! The only thing I noticed was the red battery light flashed for a split second during this loss of power...

Has anyone else had this happen to them, or have any idea what it might be?

My car for reference is an AT model (Jan, 2004 build date) and has 1000 miles on it.

Thanks,

---Dave

Omicron

My car "hesitates" at about 4500 RPM when it's cold, but research tells me this is normal. The cold engine ECU maps are totally different from those of the fully warmed up car. Your problem sounds like something different, most likely ignition related. I'd get it into the dealership if I were you.

310Guy

My auto does the same thing when the engine is cold. One time I was trying to cross an intersection and my 8 felt like it was going to stall right in the middle of the intersection. Thank God it was 5:15 a.m. so there was no traffic...

drseid

Thanks for the reponses guys... Looks like I will take my 8 back to the shop on Monday evening (so that the dealer can replicate the problem Tuesday morning). Boy, oh boy, 3 repairs in 3 weeks (1 times it was the CEL, the next a new catalytic converter needed to be installed and now this)... Love the car, but man, it is a lot of effort keeping her healthy!

I will say that when the dealer sold me my 100,000 mile bumper to bumper warranty with a 0 deductible for $1200, they had no idea how much of a loss leader that really is going to be. ;-)

---Dvae

RobDickinson

drseid - I was going to suggest a dodgy CAT but you've just had it replaced

CEL could hvae killed the CAT? That all could be caused by a dodgy O2 sensor?

HeelnToe

Mine does it too when cold. Reminds me of turbo lag. When I hit the accelerator to merge into traffic at the end of my lane, it hesitates for a second before the power comes on.

It doesn't always happen, but does only happen when cold. It's fine once I get a few miles down the road.

I figured it was just a normal rotary thing when not warmed up first?

Dordav

Same thing happened to me yesterday. I've got about 2500 miles and it only happened that one time.

JeRKy 8 Owner

Youguys think that is bad? Sometimes if Im going over 50 on the highway and I suddenly drop into 2nd gear using tiptronic mode the entire car pounds/jolts forward. Feels like I just flipped a switch for nitrous. This is obviously longafter the car has warmed up. It neverused to have such a rough pickup like this but then againI am already over 13000 miles and Idont exactly baby the car. It doesnt happen all the timebut it occurs enough to the pointwhere its become noticeable. I kind of likethat "jet forward launch" typeof sensation I get butI know it cant be too good since my Rx8 never did this several months back.

Mr M

Sounds like a spark problem, the battery light flickering could be an indication of a near-stall condition. Replacement spark plugs and trying another set of coils would be a start.

On the fuel/air side, maybe someone forgot to connect the jet-air port pipes and you have fuel puddling in the ports at idle.

It could also be something to do with the A/T, or even the engine management system. There are so many possibilities...!

I am interested in this though, and why it is mainly on A/Ts...Let us know the results of your check up.

amartin

Are those of you with problems using the M-Flash?? Mine started doing this after I got the M-Flash.

Mr M

I drove three different 8s today and could feel the fuel being cut on all of them when I hit 4000 rpm with the engine stone cold. Totally normal. The engine light coming on however is an abnorm. Get it looked at.

JERCS

Mine does it almost every morning at the stop sign after my condo. Does it only once, but I get complete fuel cutoff and almost come to a dead stop. Only in the mornings though, when it's not so warm out, wouldn't exactly says it's cold though.

Mines an MT with 19k

LewNutz

What you guys are describing sounds like what is written in the manual:

Page 5-4 of the Manual (US Version) in the Note box:

"To protect the engine, when the engine coolant tempurature is low, the engine does not run at high speeds. The fuel supply will be cut at an rpm lower than the red zone."


I would say that this is by design and perfectly normal.

JERCS

When I first got it the fuel cut off was at 6k if it was to cold, did that once. This is totally different, feels like a stall, I don't even get moving from idle to 1.5k and complete powerloss for a sec.

amartin

It occurs between 1->4k RPMS not 6k+.

-- Aaron

LewNutz

Oh, then I have no ideas. I would take it to the dealer and have them check it out.

amartin

Its at the shop as I type right now. I'll post an update when I get one.

drseid

I have mine still at the dealer (since Monday afternoon)... I should have something to report later today.

Oh, and to answer one person's question, yes, I do have the M flash...

Hopefully they will find out what is wrong with the car, and this will be my last visit to the shop for a while...

BTW: The service rep first asked me what octane fuel I was using... I first thought he was going to chastize me when I reluctantly replied "87," but he said that the hesitation problem is sometimes caused by the use of 91+ octane (I have no idea why). I guess just another reason to ignore Mazda's "recommendation" and save some money on gas. :-)

---Dave

amartin

Just got my diagnosis-- Burnt Coil.

Should have the car back in 1-2 days, part was ordered.

...so now you know... when it takes 15seconds to gain 1mph at 40mph at WOT, you've probably got a burnt coil.

... I too have the M-Flash.

-- Aaron

HeelnToe

Did yours stumble consistently? I assume it happened all the time, and not only when cold?

amartin

Actually, it ran much better when it warmed up...

Cold, it ran like complete crap-- couldn't backup outta my driveway onto the hill w/out it dying... 2nd gear (@10mph) at WOT would stumble and sometimes actually stall the car.
-- I could no longer start-out in 2nd gear (I used to be able to)

..once warm, lots of the stumbling symptoms went away at low rpm's, BUT I'de still have little to no power under 4500rpms.

-- Aaron

drseid

In my case the diagnosis is "we don't know what the cause is..." Evidently the service department says that they have had several automatic 8s come in with the same problem, but they say they can't think of any cause for it. Evidently, I just have to warm up the car for 60 seconds before takeoff in the AM. They think it is ust an anomaly of the renisis engine (or maybe it is just BS).

They *did* find problems with my A/C and dirty brake rotors... So I guess the trip was not a *complete* waste... Only problem is the A/C part has to be ordered, so it looks like another trip to the shop is in my near future. :-(

Thanks again to everyone who tried to help out.

---Dave

amartin

Have your coils check out-- or ask around how to check them yourself.

I noticed that when mine went bad, I also had even worse (is that possible!?) gas milage-- I dropped to 11mpg from ~15.5

-- Aaron

drseid

Thanks Aaron, I'll do that... probably when I have to take it back for the A/C Amplifier replacement when the part comes in.

---Dave

amartin

Just an update-- got the car back. WOW!!!!!

Totally different car! I mean its just night and day.

Anyway, Here's the Tech's Note on my invoice: (BTW, this was covered under warranty)

Found normal rotary eng cold start at this time called Mazda hotline talk to Lance REF#357485 was told to update pcm with updated calibration M and thats all we can do at this time. Note: Also recommend to use high octan gas. Car came back with same problem looked ignition coils over found 1st and 3rd coils to be melted on top were conector connects, R&R Coils and all four plugs and CK main grounds per hotline tech Luis to correct. Test drove no further problem.

(Typed verbaim)

It wasn't until a friend of mine that works at Mazda told the tech to inspect the ignition coils that the tech found the problem-- the computer reported no codes, etc...

-- Aaron