No power past 2nd gear

[YlwMSP]

I don't really know what could be causing it to have no power in any of the higher gears, but its kinda disappointing. Especially with the mods I have done to the car, which are SSAFC, ebay FMIC, pope dp, and corksport 3in catless exhaust. It does have a CEL right now for the VCTS actuator being bad, but I doubt that would cause the car to fall flat on its face in higher gears. AFR's are good while in boost, and it hits full boost without any problem. Anybody know what could be causing it to bog down like this?

 

[Stiki]

could be an exhaust issue, if you have a resinator or muffler with internals, make sure nothings rattling and/or clogging. no other codes?

 

[YlwMSP]

The only other code I randomly get is the secondary O2 sensor not getting any signal, but i just haven't adjusted the spacer that came with the exhaust. Nothing else really rattles, other than intercooler piping due to the AWR motor mounts being so stiff. I'm leaning towards that being most of the issue. Somewhere there's a boost leak when under throttle.

 

[YlwMSP]

This is kinda getting to be an older thread, but today when I started the car, it just kinda started, not really strong. Just like it was woken up after a night of heavy drinking. Could these be ignition issues?

 

[Dr0]

could be a lot of things. some concrete info would be nice. i had a stumble/hesitation for the longest time and getting it reflashed for 80 bucks cured 95% of the issue. If you're using a flashed ecu already then check your plugs, clean your maf/TB, maybe try a can of seafoam.

If you want someone to diag your exact problem you NEED to be very specific and detailed

 

[tweety2300]

I doubt they're related sounds like a boost leak, I deal with it a lot, t25 is small enough to still build enough pressure but the air flow will be way off what it should be.

 

[YlwMSP]

Alright, I'll try to get in in the shop at school to see what it is. It really does just fall flat on its face when I get into higher gears. It revs up just fine, just doesn't go...I got beat by a friend's hyundai azera lol. Thanks guys, I'll keep you all posted when I find out more.

 

[Stiki]

when you say fall flat on its face do you mean like a fuel cut?

 

[Dr0]

get you're ecu flashed at a mazda dealershit for 80-100(depends on labor rates which vary). or get a EMS like halltech, MS, unichip and forget about the BS factory ecu. IT SUCKS... everyone knows it, why do you think threads with the common symptom of hesitation/falls on its face/stumble/boost issues all end up with answers saying you need to get EMS to get rid of the factory ecu issues.

Keep in mind that many people have been succesful with the car without EMS's thats why i stated that you get yours flashed. Its not 100% fix but its a really good bandaid for the price you pay. It was a night and day difference for me, i still have an occasional stumble in boost and the car acts all funny but usually shutting the car off and restarting it brings it back to normal.

 

[Installshield 2]

The VTCS thing could be it...are you sure VTCS isn't stuck closed?...and are you also sure its VTCS, and NOT VICS?...very different systems...

if VTCS is stuck closed (it 'turns on' during a cold start, then opens after coolant hits a specific temp), it very much will gut engine power at higher load and revs...VTCS is just an elaborate choke...

based on your given code...i'd start with that...its not all that hard to remove completely, anwyay...

 

[YlwMSP]

I get the P0140 code, I may have gotten the VICS and the VTCS mixed up when typing it up earlier. I believe it's the actuator that opens up the valves. I don't really want to spend the $100 on the actuator to fix it. And I have an SSAFC installed, running the stocksupermap. Is it really even worth it to reflash the ECU if I plan on running 8 or 9 psi once everything is all straightened out?

It's not fuel cut, it's like the engine revs up, but it doesn't pull while doing it. I've talked to a few people and they said that the valves in the intake wouldnt make that much of a difference since the car is boosted, it should just push past in the primary runners.(It makes sense, but unless the MSP is weird and that's not how it is on this intake)

 

[Installshield 2]

Well dude, I don't know these friends of yours... But think about what they are saying. Look at some pictures of vtcs, and notice how restrictive it is when closed. While a turbo will push air through still, it would be no where near as much as needed.

If your friends logic was true, you could run the smallest diameter intake system you ever wanted... Like a garden hose... But the turbo would just push enough air through, right?

 

[Dr0]

the way you explain it sounds just like the symptoms i had before the flash. before the flash the car would pull too much timing and the car would boost fine but it wouldnt go anywhere and it would feel slower in boost than out of it. the flash just advances the timing to avoid this condition.

i am not really sure the butterfly valves in the intake would affect performance as much as you are stating. im not saying it CANT but i doubt it would.

 

[YlwMSP]

Thanks guys, I'll be back up on campus this week and I'll take a look at getting that actuator fixed. I've read somewhere on here that people have tied the actuator arm so that the valves are always open and seemed to work, but then again, who knows if that person was actually telling the truth. And as for the reflash, do the Mazda dealers still have it, with the platform being 10 years old now?

But I do have confidence in what my buddy is saying, but then again, he's a Honda guy with a soon to be 700+ rwhp s2k, currently at 460 rwhp. He has no experience with this VTCS stuff lol.

 

[Dr0]

yep any mazdaspeed certified dealer(just call and ask) has the info. when i went in it took the guy about 10 min to find the tsb, and it took 45min to get the flash. and yea you can zip tie the butterflies open and try that out if you want, since it would be free and all.

Keep in mind that the flash is not a complete fix and you will occasionally still have issues but it does help (like i said... it made a huge difference for me)

 

[YlwMSP]

I do have the SSAFC installed on the car right now with the stock supermap loaded on it, I'll have to wait til I have time to go to the Mazda dealer since the closest one to me is an hour and a half away.

 

[tweety2300]

If you have ssafc there shouldn't be a tuning issue

 

[Installshield 2]

Thanks guys, I'll be back up on campus this week and I'll take a look at getting that actuator fixed. I've read somewhere on here that people have tied the actuator arm so that the valves are always open and seemed to work, but then again, who knows if that person was actually telling the truth. And as for the reflash, do the Mazda dealers still have it, with the platform being 10 years old now?

But I do have confidence in what my buddy is saying, but then again, he's a Honda guy with a soon to be 700+ rwhp s2k, currently at 460 rwhp. He has no experience with this VTCS stuff lol.

yeah cool, i'm not arguing with him...i'm just saying that Turbo designs do respond to restrictions the same way NA designs do...it just results in different things...

If VTCS IS stuck closed...i promise that will cause almost no power at upper rpm...despite a turbo spooling wildly in front of it...the wastegate (not sure of your mods, though) will just let it out because of intake reversion...a blockage like what VTCS causes is fine for low rpm (the system is designed for that)...it keeps air volume relatively low, but keeps it moving at high speed...as revs increase, breathing requirements change...regardless of the turbo pressurizing everything...and a T25 is not going to overcome that level of flow restriction...you'd need a turbo that flows a whole lot more volume to get enough air through that to 'not notice'...

so a very simple diagnostic would be disconnect the actuator and move it by hand and drive around...you'll get a code for it, but you'll know immediately if you're building power at higher rpm again...if that doesn't change anything, do the reflash...do the reflash anyway, i'm not arguing that...just saying if its VTCS related, the reflash won't fix it...

 

[YlwMSP]

Cool, it's been super cold here in Minnesota the last few days, and school is pretty hectic right now, I know I already have the code for the bad VTCS actuator, I just plan on tying it up so that it's open all the time and see if that works till I can scrounge up some money to replace the actuator, or just get a 626 manifold.

 

[Stiki]

this really sounds like my msp when my catalytic converter blew chunks into the resinator and clogged it..i could rev it no problem, but driving it past 1st gear was sad...symptoms are as you described and the exhaust got quieter, didnt build boost past like +2 psi

if your exhaust got quieter check your exhaust system