Car bogs under acceleration when warm

[b_dues]

Hello all,

The issue I am having is a tricky one because there are no signs of the problem until the car is driven for about 30 minutes. Also, there is no check engine light so with a mix of the two, every mechanic I take my car to is stumped.

To clearly describe the issue, after I drive my car for about 30 minutes it starts to hesitate, stumble, sputter and bog/decelerate when I try to accelerate. I have no vac leak, the plugs, wires and coil packs have been recently replaced and I just had the timing belt replaced. My car has 175,000 KMs on it. I drive this car like an old lady so it can't be due to abuse. Has anyone ever experienced this or can anyone suggest what it may be?

Edit: I should also add that I can accelerate very slowly if I give maybe an 1/8th throttle and build boost slowly or if I play with the clutch and gas pedal to increase revs. When in neutral I can rev the car but it sputters.

 

[thecrash91]

sounds like heatsoak to me, but you have FMIC so its not likely, maybe coil packs or wires? do you have a wideband o2 to check what your ratios are while this is happening?

 

[b_dues]

No I don't have a wideband but I do know that my car runs rich. It's at the dealer right now and they are trying to figure it out. Should I go for a re-flash while it's there?..if that would cure the a/f ratio. It shouldn't be coil packs or wires because I just replaced them about 5,000kms ago but maybe plugs could be the issue? Any other ideas?

 

[b_dues]

Bump

 

[bassjas12]

Bump

From What i have read on these forums, the reflash helps with the issue, but does not fully solve it. The real fix is to get a Split Second AFC controller and set it up with one of the pre-configured maps in the Engine section of this fourm. It will completely fix the A/F ratio since you are manually setting it with the SSAFC. This is on my TO-DO list since I have a similar issue.

 

[b_dues]

Yes, that will cure the hesitation issue and will fix an a/f ratio but my problem is with the bogging. I have a hard time believing that such bogging is a result of a rich mixture. I think my a/f ratio may add to the problem, but is not entirely responsible. My issue is intermittent and is intense (to the point of requiring a tow truck because it is stalling and won't accelerate), not just annoying. Mazda can't figure it out because there is no CEL. Can a bad MAF or even bad plugs cause bogging this bad? I know bad plugs can cause a misfire and such but this is almost as if the car is on a limiter when the throttle is pressed too fast or any further than an 1/8th pressed.

 

[bassjas12]

Hmm.. that is bad. I had a plug go a little while back, but it just caused a misfire as you said. Car would still run, just with little power. Felt like driving a big go-kart. I remember reading somewhere on these threads about the car going into a "limp mode" that sounds similar to what your describing. Something about keeping the engine from blowing up. I dont really recall. Perhaps someone with a little more knowledge can jump in here!!! But that's what it kinda sounds like to me.

EDIT:: After a google search, here how i understand it: Its the ECU that goes into the Limp Mode. It limits the car from running too hard if an engine issue is detected. One guy said it was from a bad fuel pump on his, another suggested from engine pings. The fix is to reset the ECU. Not entirely sure how that's done.

 

[b_dues]

Pretty sure the ECU can be reset by disconnecting the positive terminal. Wouldn't that "limp mode" throw a CEL though? I would think a bad fuel pump or an engine problem would.

 

[b_dues]

This is the definition of "limp home mode": http://wiki.answers.com/Q/What_is_a_limp_mode

This sounds very similar to my problem. The only difference is that I can still rev my car to the red line when in neutral and the idle stumbles and sputters as if there was a leak or ignition problem. Also, this definition mentions that the car's speed may be limited. I drove home at 120km/h while the problem was happening, it just took time, patience and crafty play with the gas pedal to get to that speed.

 

[bassjas12]

ha. Well I am out of suggestions. I will keep looking around. Not sure whats up. Maybe the Mazda techs will figure it out. Or someone else will chime in here with the answer.

 

[b_dues]

Thanks for your contributions, I am in need of any suggestions because this problem boggles my mind...and apparently the minds of trained technicians.

 

[StealthWyvern]

I want to say its your MAF going out.. find another protege buddy and swap them out for a little bit to test.

Edit: Does it act like this... http://www.mazdas247.com/forum/show...misfire-no-power-under-load-issue.&highlight=

 

[b_dues]

It is very similar. I have all of those symptoms except when my car is freshly started I can drive it regularly for about 20-30 minutes and then the sputtering/bogging problems arise. Was yours constant or intermittent like mine?

 

[b_dues]

Just got my car back from the dealer. They took it for a 20-minute drive and of course it didn't act up during the drive. They didn't charge me, thankfully, but the problem is also not fixed. I guess I will just see if it happens again and try and find someone with a MAF near my location in the meantime.

 

[StealthWyvern]

consistant and got worse the move i drove it... IE got wose day after day.

 

[CHIQLES]

hmm I say its electrical something is heating up expanding and cuaseing poblems thats why when its cold its fine then after heating your screwed. I say swap coils andwires get new plugs gap them at .30 clean maf and you maybe good.

 

[CHIQLES]

does the car stuter under heavy load but drives fine otherwise..if so i did the above to fix.

 

[b_dues]

Under load, and barely any load at that, it stutters/bogs.

 

[shane02pro5]

No cel's? Compression test? (pick a tester up at the local auto parts for $20) I would think you would at least throw a misfire code if there was a bad valve seal or bad ring which would be worse after warmed up. Crack in the turbo mani? Sprinkle baby powder on the mani and crank it up.

 

[b_dues]

No cracks in the mani, just replaced with a Steedspeed last summer.