High LTFT's and Hesitation

[Silver Ecstasy]

How would you suggest doing a vacuum test?

[easy]

maybe ask around at shops or possibly the dealer to see if they can test for vaccum leaks. If they do, they may have a machine that pumps smoke in one of your vaccum lines and the leaks will become apparent if you have any.

or u can try and spray carb cleaner and see if it gets sucked up and fluctuate rpm

[BudUMfan]

Originally Posted by Silver Ecstasy How would you suggest doing a vacuum test?

I used a propane torch (unlit of course) and traced the vacuum tract. Rpm's will rise if sucked in. Dealer did the same thing, along with smoke test.

[Silver Ecstasy]

Hmm. Ok.. lol don't know if i'll be doing that.

[matsuda]

Originally Posted by FORZDA 1 Dude, I've been trying to be courteous and push you towards learning a bit about the specific open/closed loop switching logic in the Speed3/6 ECU, but it's plain to me you're simply a troll who has read some basic theory in the SAE documents that define the basic PID standards that the OEMs must follow in setting up their OBD communications for viewing by scanners, etc. It has nothing to do with the actual ECU function. Quoting basic PID info from the SAE standard just proves how little you actually know. It may impress some folks who have no clue what's going on here, but from my perspective please just go away if you're not going to learn anything because you obviously have no real knowledge about the information you're posting and crapping up this and the other threads you've posted in.

Wow... I'm sorry to confuse you. Allow me to simplify my response so as not to confuse you further:

The IDS confirms that LTFT does not zero out when running WOT / open loop (i.e. your assertion is wrong). Is that simple enough?

The point of the J1979 spec. was to let you know that fuel system status can be correctly monitored by a standard "OBD2" scan tool that supports this function. The IDS of course has ALL of the Mazda specific PID's (including many that are not found on a DH). Needless to say, you really cannot see the whole picture unless you have an IDS.

If you have any evidence to prove that the IDS is not logging data correctly, I am all ears.

Originally Posted by FORZDA 1 The fuel trims WILL change if the intake size parameters (size, length, MAF position, etc.) are not EXACTLY the same as the OEM calibration("metering"). The changes may be small or LARGE, depending on what has changed.

Yes, now you're getting the idea.

Just as I said, "If the air is metered properly, the fuel trims shouldn't change..."

[matsuda]

Originally Posted by fjames On the intake vs. fuel trim thing - I don't see how you can a. let in more air consistently over time b. say that because of this your ecu increases fuel c. claim no fuel trim change d. because that IS a fuel trim change.

Aren't you forgetting the fuel maps?

Think of fuel trims as a bias or correction to the amount of fuel that is determined primarily by a fuel map. That is why they are called "trims".

As long as the incoming air mass is metered correctly, the ECU will "deliver" an appropriate amount of fuel. The amount of fuel is determined primarily by a table (fuel map) and is only biased by the fuel trims.

ONLY if the target AFR does not equal the actual AFR (as read by the O2 sensor), then the ECU will adjust the fuel trims.

In the OP's case, the Cobb has a high LTFT simply because the MAF voltage is lower (for a given air mass) than the stock air box. This is caused by differences in the MAF housing (MAF sensors are very sensitive). If the relationship between air mass and MAF voltage were identical for the two intakes, the fuel trims would not change (i.e. no correction would be necessary because the metering of the air is the same).

Maybe you have read about people installing an air straightener on their Mazdaspeed intake. The air straightener enables the MAF to meter air more accurately, which results in a difference in MAF voltage and thus a difference in fuel trims.

[Silver Ecstasy]

Speaking of which,

I decided to install my Cobb SRI combined with the Cobb TIP this time around. Last time, it was only the Cobb SRI with stock TIP.

Fuel trims are immediately down to +6 and +8. Interesting. Hesitation is less pronounced, although the car definitely had to get used to the different intake. For a few runs, in 2nd gear, you'd hear the turbo spool up but the car was going nowhere, then all of a sudden you'd be pushed back in your seat. I've had intakes before, i've modded before, I know what it's supposed to feel like. It didn't feel like that. Anyways, will report back if I continue to notice hesitation. I'm thinking it's time I changed for brand new stock spark plugs.

[FORZDA 1]

[QUOTE=matsuda;420403]............If you have any evidence to prove that the IDS is not logging data correctly, I am all ears..........[QUOTE]

Nah, I’m done debating the issue as we’re crapping up this thread and you obviously have your mind made up so words will not sway you. The ECU logic is the baseline for all things displayed on a scan tool. Yours works the way you say and mine works the way I say………

For other's info here are a few sites for excellent OBD tools to assist you.
I like this one with Mazda/Ford enhanced SW and use it in my garage.

OBDScan-APEX - OBDII Diagnostic Scanner

http://www.obdscan.net/obdscan_mazda_m63_enhanced.htm

If you really want the OEM tool go here:

Ford Mazda Ids

or maybe here

mazda IDS VCM Products , China mazda IDS VCM Manufacturers, China mazda IDS VCM Suppliers, Made in China, Exporters, Factories - DIYTrade

[YokiMazoku]

I had a very very similar problem however my car threw a code to help me figure out what it was. Try replacing your spark plugs after i did that it went away. I had to replace my plugs at like 20k or less.

[YokiMazoku]

Oh i almost forgot the second time this happened to me it was bad gas in the car. But im sure you probably have already ruled this out.

[Silver Ecstasy]

Originally Posted by YokiMazoku I had a very very similar problem however my car threw a code to help me figure out what it was. Try replacing your spark plugs after i did that it went away. I had to replace my plugs at like 20k or less.

Thanks for the tips! I am considering replacing the plugs.

[Silver Ecstasy]

So i'm starting to think that the Cobb TIP is an absolute must with the SRI. Not only does it make it that much more fun to drive, but my fuel trims are half of what they used to be, and the car is running like a champ. Very pleased so far!!!

[SRTie4k]

Interesting, because I have a similar problem with the Cobb SRI. My LTFT's are pretty crazy too:

Idle - +16.4%
Cruise - +8%
WOT - +10%

I also have a SU TMIC, so I checked for vac leaks and tightened all my hose clamps thinking it was a vacuum leak and unmetered air. That didn't fix it. Then I cleaned my MAF, that also didn't fix it.

Maybe I need to order a TIP.

[Silver Ecstasy]

I'm not kidding man, order a Cobb TIP now.

Not only does it make the SRI that much better, but my LTFT's are spot on. I love it!!!

[IndianOutlaw]

I just bought the PG inlet so we'll see what that does to the trims with a cobb sri

[JohnMS3]

anybody figure out why the cobb sri is causing these high ltft's? i have a cp-e nano an planning on switching over to cobb just for the carb sticker

[Silver Ecstasy]

No idea man, and I won't even try because I hate the "theories" method.

[felt]

Was your stock inlet securely clamped to your turbo???

[Silver Ecstasy]

Yep. It was on there real good. I made sure to check as I was removing everything basically.

I'm thinking my o2 sensor still needs to be replaced, along with plugs. I'll be able to tell better once it warms up (if it continues) but as for now, i'm having way too much fun with the complete intake lol.