geekboy2000

I've had my Stang for about 10 weeks now, and love it. I did have it in once for service for the following problem:

It seems that when it's hot (I have to say ambient temp more so than engine temp) and humid, and particularly if running the A/C, the engine "bogs" (for lack of a better word). It just feels as if I've got a refrigerator tied to the back of the thing when initially leaving from a stop, but after a few seconds of being on the accelerator, it'll "kick in", almost as if it's got a turbo. Likewise, in second gear. There's kind of a "lag"/"dead" feeling initally, before it roars away as it usually would. Now, here's what the dealer told me:

No fault codes where set, which he stated ruled out spark, timing, and sensor issues. He said he leaned more toward fuel. He suggested I try a few tanks of gas from somewhere else (I had been running it on WaWa 87 grade). My understanding is that the engine is setup to run on regular, but just for the heck of it, I started running BP 93 octane or Sunoco 93 octane in it. That *does* seem to make a difference. Is it perfect? No. But, it's much less noticeable. Now to my question:

How should I approach this with the dealer, if I should at all? They are pretty much saying, "There's really nothing wrong - try different gas". I've done that, and seen a difference, but that leads me to my next question:

Would I potentially be doing more harm than good by running 93 octane in the car?

And, finally, Is there an "It's so easy, even a caveman can do it" replacement chip or performance add-on that might solve this?

Am I alone with this scenario?

Thanks very much!

Mark

[IMG]local://upfiles/73178/DA778300AB8147B39EEAE46E9C7E2CD9.jpg[/IMG]

geekboy2000

As a follow-up: Would a new CAI and tune likely resolve this? My only problem with that, is: "Why should I need an aftermarket CAI to have the vehicle run as it should in the first place?". I think, after some reading, I'm not doing much good by running 93 octane, so I might switch back to 87, but stick with BP or Sunoco.

Mark

mlcrycc

Welcome to the forums......

You aren't going to hurt it by running 93 octane, only your wallet. If you are going to run 93, you might as well have a reason for doing so, I.E. a CAI and Tune. Yes, it's so easy a caveman can do it. Best first mod you can do. It will eliminate most of your "throttle by wire" lag.

That being said, even with a tune and CAI, heat and humidity effect performance, regardless. Last weekend, we had 110+ degrees with about 55% humidity......Car was a total dog. This week, humidity gone, temps in the low 80's.....Car feels like it picked up an additional 20 HP.

Welcome, and best of luck with it.

Mike

offrdmania

Any car with an A/C onand it being warm outside is going to bog in those conditions. Its the nature of the beast.

Gman13

Geekboy,
I've had the same issue with my '05 and it does suck, but when it's that hot and humid outside I don't want to run either...

I have a granetelli CAI with no tune, and it still happens. My warranty is up, so I'm going to tune it now but haven't done so yet. Hopefully it will help but like Offrdmanie and Mike said, it is kind of the nature of the beast.

Here's looking forward to cooler weather...
Gman

mlcrycc

LOL....I thought we had been transplanted to Texas last weekend....At one point on Sunday, our thermometer was reading 116. Keep in mind this is So Cal!! I don't know how you guys do it regularly....[:'(][:'(]

Much nicer now. low 80's no humidity....Time to go install the replacement flows.........

Mike

geekboy2000

Thanks Mike, and to the others who responded as well. Yes, the days when I most notice this are +90 degree days w/high humidity. As you mention, with temps at or below low 80 to mid 80's, it truly does feel like a different car. If that is the nature of the best, and to be expected, I'm fine with that. I was just afraid I'd been stuck with an intermittent problem that would likely never be resolved. I think I'll switch back (perhaps in steps) down toward 87 octane.

Mark

ohfiveride

i had the sam exact problem today...it almost stalled when leaving from a dead stop then the "turbo" kicks in and its fine..i hate it

geekboy2000

I've found that as a pretty decent workaround, in those conditions, I give it significantly more throttle before letting the clutch out. I guess I'm adopting cool weather/hot weather driving techniques. But yes, it's annoying. Fortunately though, with fall approaching, this might soon be a thing of the past until next summer.

Mark

[IMG]local://upfiles/73178/3E4D5B5B37AE4416BD9E9ED8D78B03C8.jpg[/IMG]

kastigar

i had a simialr experience, when i put on my CAI and tune it seemed totally gone for me. then in the beginning of summer my car overheated, i think the thermostat is bad, so i took off the tune and the CAI, the car doesn't overheat now, but the bog is back. And yes its worse when its hotter and the A/C is on.