Discussion on how bypass valves can affect LTFTs.

[Sacrilicious]

that's good to hear. i'm not quite sure what might be causing your surging, though. do you have a logging device so that you can take logs of when this happens?

[shpankey]

I just have a DTC/ABS code reader. It can look at most parameters "Live" but I don't think it can log. I'm thinking about getting a DH though, if for nothing else than to do some logs and see if someone here can diagnose the surging issue. I'm starting to just think I did one too many mods w/o any kind of tune.

[gtarman77787]

hey -- i read your OP -- freaking perfect -- thank you so much
i'm currently running an HKS ssqv -- and i was getting a random pop between shifts -- i guess its to be expected -- but now it all comes together and makes sense

i'm just speaking my mind, but if i were to disconnect the battery, the ecu would have to "re-learn" ST/LTFTs again correct?

I'm not saying its a "solution" per say -- but is it possible to teach your ecu different trims by resetting your ecu and driving it differently than you originally would?

i'm really just speaking out of my ass -- i have no idea about this

thanks again for your OP -- it was very helpful

[Sacrilicious]

Originally Posted by shpankey I just have a DTC/ABS code reader. It can look at most parameters "Live" but I don't think it can log. I'm thinking about getting a DH though, if for nothing else than to do some logs and see if someone here can diagnose the surging issue. I'm starting to just think I did one too many mods w/o any kind of tune.

what exactly are your current mods and do you have a gen1 or genpu?

Originally Posted by gtarman77787 hey -- i read your OP -- freaking perfect -- thank you so much i'm currently running an HKS ssqv -- and i was getting a random pop between shifts -- i guess its to be expected -- but now it all comes together and makes sense i'm just speaking my mind, but if i were to disconnect the battery, the ecu would have to "re-learn" ST/LTFTs again correct? I'm not saying its a "solution" per say -- but is it possible to teach your ecu different trims by resetting your ecu and driving it differently than you originally would? i'm really just speaking out of my ass -- i have no idea about this thanks again for your OP -- it was very helpful

if you simply reset the ECU, it would just go right back to what you had before over time. the point of the learning is that it keeps adjusting itself to what the MAF currently reads, so unless you can somehow affect the hardware that controls air flow, you're not going to be changing anything. if you want to confirm that the hks is causing the popping because it's forcing your LTFTs higher than they should be, just record down what your current WOT LTFT is, and then go back to the stock bpv...give it like 20 miles of moderate driving and see what your LTFTs are. assuming that this was your problem, you should see that the stock bpv's LTFTs will be significantly lower than the hks', and your popping will be gone.

[shpankey]

Gen 1. It's an 09 MS3 GT
19k miles
Current mods:
Cobb Short Ram Intake & Turbo Inlet Pipe
Street Unit Test Pipe
Turbosmart Bypass Valve
KMD Version 2.1 High Pressure Fuel Pump internals

Like I mentioned, my first mods were the SRI, TP and BPV. I ran those for a long time by themselves and the car was an absolute BEAST. I raced several MS3's, one with more mods than me and beat them. Not saying anything here other than trying to relay the car ran very, very strong.

Then, in December of last year, my wifey bought me some Christmas presents. The KMD ver 2.1 HPFP internals, a CP-e RMM (60 dur and currently off my car, being replaced by CP-e), Denso ITV22 step colder plugs and the Cobb TIP. I installed them all on Christmas Eve. We were literally snowed in for the next month, and I won’t drive my car in that weather. So I didn’t get to test it for quite some time. But when I did, I knew pretty much right away something was wrong, as the car did not pull correctly.

There’s a place when coming home, a bare open stretch backroad with nothing around for miles and miles, that I always take coming home. I usually do a 2nd gear roll pull on it. Before those last mods, I’d just punch it in 2nd gear (no clutch drop, just at 4k rpm’s put the pedal down all the way) and the tires would ROAST (I turn off TC w/ the trick) and shift to 3rd and they’d still spin. Finally it would start getting traction and shift into 4th and it would bark the ever lovin crap out of the tires. I could barely hold onto the wheel sometimes, lol… the car would pull like an absolute BEAST!!

But after those mods, when I finally got to try it, it would not even spin the tires in 2nd, at all. It would barely squeek them in 3rd and nothing in 4th. And it was just dead. The car just didn’t pull hard at all anymore. Then in 5th I get the surging (wavy pulling).

So I replaced the plugs with NGK’s equivalent to stock plugs. Took the CP-e RMM off, tested, re-tested and tested again and again the HPFP pressure with the ‘Live” mode on my code reader. I have a friend doing co-pilot calling it out as I do pulls. Always stays above 1730 and like 90% of the time it’s between 1750-1850 with spikes into 2000. So I don’t think it’s that. It’s not the plugs. Not the RMM, of course.
I’ve tested the compression ( > 180 psi on all cylinders). Oh, and one other thing of note. Before, when the car ran right, I used to run pig rich all the time. With a bit of black smoke on shift’s coming out the back. I no longer have any smoke whatsoever. Which scares me… I hope I’m not running lean. Any chance the HPFP is what cured the black (fuel) smoke on WOT pulls?

p.s. I've cleaned the MAF, MAP, EGR, EGR Pipe & Throttle Body several times each.

p.p.s. If this helps, here's another thread on the forum with a guy having pretty much the same surging problem as me...

Car pulls in waves between 170 and 220Kmph

...though he doesn't mention the loss of power that I have. The surging he describes is the exact same thing I have though.

[Sacrilicious]

hrrm...from what i can see, the KMD internals and the densos are what i would first think about. since you're still running stock boost, i think the easiest thing for you to check right now is to go back to the stock plugs and see what happens. there's a chance your densos might not be gapped correctly, which could definitely mess with things. there's also a possibility that your KMD internals are acting up, so i'd check that out with a DH as soon as you can. definitely go back to the stock plugs first, though...it's a really easy sanity check that you can do to start narrowing things down.

[shpankey]

I mentioned this, but yeah, I've already went back to stock plugs. That's what I have in now. Didn't help any. They are currently gapped at .28 btw. Which is how they came, but I checked them before putting them in.

As for the KMD HPFP Internals. Like I said, I have a nice scan tool that monitor's everything "Live" (no logging) and have done literally tons and tons and TONS of pulls while monitoring the fuel pressure and at WOT, it never, ever, ever goes below 1730 psi (the lowest I've ever seen) and it almost always between 1,750 and 1,850 psi. With spikes all the way up to 2,000+ so I don't think that's it.

If I still had my stock FP internals I'd put them back in. But I broke the retainer clip on it, and I called PTP and CP-e asking if I could buy one but they said they need them themselves.

If I knew for a fact it was the HPFP, I'd buy a new PTP or CP-e pump and move on, but I just don't think mine is a problem since it's so rock solid steady on it's psi numbers. The thing is, the other guy having the surging issue (that I linked to) is having the same problem as me and it happened to him after he added the Cobb SRI and TIP. Which makes me think it's a tuning issue. I have a feeling the Hypertech tune, which calibrates the MAF to your intake might just fix my issue altogether... but I really just don't want to do that until I know for a fact what the issue is. I'm worried I'm burying myself under too many changes before getting the problem addressed.

If I just had a stock TIP to try! lol

Thank you for trying to help me though, I've been on a lone island out here on this issue for a very long time and it's good to hear idea's to get my mind thinking on it more. Any other suggestions/tips? I think a DH is in my near future... at least so I can post some logs. The guy on the other thread does have a DH though and has asked what he should log for you guys. So if you have any ideas, lemmie know and I'll post over there and have him log it for you. Would this help any? Thanks again bro.

[Sacrilicious]

do you have the stock intake handy? i'd be really surprised if it were the TIP, actually. although...check to be sure that the hose going from the TIP to the boost solenoid is fully hooked up. it's the hose that attaches to the plastic nipple on top of the TIP. make sure both ends of it are hooked up properly.

something to think about: if you buy a used AP for like 450 or so, you can try it and then sell it again for the same price if you don't like it...

[shpankey]

Yeah I have the stock intake. In fact, I may be ahead of you, as I had this idea too and put the stock intake back on last night. My wife drove it around all day and picked me up for lunch just a bit ago. So it had 100 miles on it since I reset the ECU last night. So with the stock intake back on, coupled to the Cobb TIP, and the TS BPV and SU TP still on, I drove it just now at lunch. Still dead as a doornail. In fact, worse than with the Cobb SRI on last night. I didn't have an opportunity to do a 5th gear pull to see if the surging issue still exists. I'll try to do one tonight and report back.

But judging from just now, the car is still flat. I checked the LTFT's btw, 0 at idle, 0 at WOT and -4.6 at med-high and I think -6.4 at med-low. So they weren't too bad, considering the TIP and BPV still on it.

[Sacrilicious]

hrrm...definitely check to see if the surging is still there, but i just noticed that you're using the TS bpv...try swapping back to stock and see if that fixes things. there's a chance that you may need to lubricate your TS valve, and it's just responding very poorly because of lack of maintenance. it sux that we're kinda just taking stabs and just trying this and that, but it's best if you change back to stock one piece at a time and see if you can isolate the problem to a given mod.

[shpankey]

Good idea. Will do. I was kind of on the same page as you, as this weekend I took the BPV off and since I didn't have the TS Multi Spray, someone here said to just use Marvel Mystery Oil. So I ordered the Multi Spray online (should be here this week) and took the BPV off and cleaned it then put the Marvel Mystery Oil on it and put it back together. I did this along with cleaning the MAF sensor (the way you told me, thanks for that btw, lol, I had been doing it wrong lol) and super-tightened all of the clamps that were boost related.

Have you read that other thread yet? Just curious. As he kind of arrived at his issue differently than me. I pm'd him today and he said he think's it's the MAF not being calibrated for our intakes. But the only thing that worries me is, he doesn't seem to mention the loss of power.... though maybe that just goes without saying.

Is the MMO safe to use as the oil for the BPV though? Tonight, I'll do as you say and put the stock BPV back on, reset the ECU and try to get some miles on it to learn the trims, then go do a 5th gear pull and check to see if the surging is still there.

p.s. One thing of note: the other guy who has this issue had it on the stock BPV. They told him to get an aftermarket BPV so he did and put on the TS BPV. The issue remained. So he had the issue on both, before and after. So he ruled it out as a source of the problem.

[Sacrilicious]

tbh, i really don't know exactly what kind of oil is required for the TS, but if i had to guess, i bet the MMO would work just fine. the oil just needs to be a lubricant, and it's not like it's going to corrode some sensitive material, so i am inclined to think that it's no big deal at all.

i have read the other thread, but i'm just not quite sure what to make of it. it doesn't happen in gears 1-4, so that's just kind of weird, since i know that the load targets for the stock ECU in gears 5-6 are pretty damn low...=/

[shpankey]

I'm not quite so sure it doesn't happen in the other gears. I think it's just not very noticeable myself. Sometimes I think I can (barely) feel it doing it in 3rd and 4th too. But in 5th and 6th it's pretty dramatic.

A friend of mine mentioned the MAP sensor. I should point out, that when I did the install of those last mods on Christmas Eve, I did take the MAP sensor out and cleaned it. I don't feel I did anything wrong, as it's was pretty straightforward and easy to do. But since he brought up the MAP sensor as a possibility, I thought I should point out that I did clean it at that time. Along with the MAF, EGR and EGR pipe and air filter. I was bored and snowed in, lol.

He also said something about a slipping clutch. Is this a possibility? I have 20k miles on it now, but this issue started I think at around 13 or 14k miles.

You've been a big help btw. At least I finally have someone trying to help me. This issue has me fairly depressed about the car lately. It really sucks. I just want to figure it out now. I don't care what it will cost to fix, I just want it done and over with and get back to having my real car again. I miss it so!

I have Matt's awesome Oil Catch Can kit, and Devil's Own Methanol Injection kit (along with his new sump pump resevoir, and the CP-e 75 duro Rear Motor Mount all sitting in my garage, waiting for me to fix this problem. I'm not installing anything else until I get this problem fixed first. As soon as it's fixed, I'm putting all of those things on it, along with ordering a throttle body spacer w/ meth tap and a Hypertech tune. I'm going to drive it that way for awhile then get ready for my final mods.

An AutoEVE TMIC (I love the way it looks, I know it's overpriced), carbon fiber hood w/ functioning scoop, side mounts and PTP tranny mount, PTP turbo manifold, ported & polished intake manifold along with a PTP intake manifold spacer, a Corksport Downpipe w/ High-Flow cat and then taking it to Plano, TX to have Cobb put on the AP and do a pro custom dyno tune to dial it all in.

[shpankey]

I posted this in his thread, but since this one i left w/o an answer will do so here too..

Ok, I put the stock Intake back on. But I left the Cobb TIP, Turbosmart BPV and Street Unit TP on it. Drove a few days and got almost 300 miles on it for it to learn the new trims (LTFT's are now, idle = 0, pt= -4.2, pt= -6.4, wot= 0 btw). For reference. With the SRI, TIP, BPV & TP on it, my LTFT'S were pretty far off, from +10 to +14 I can tell you, the wavy pulling is completely gone in 5th and 6th gears now. So there is something going on with the intake or the tune of the maf on the Cobb SRI & TIP combo.

Personally, I still have the power loss, though not as dramatic, but it's still there, or not there actually. But the surging is completely GONE 100% now with the stock intake back on.

[Sacrilicious]

uh oh...maybe there's something weird about your cobb sri? did you check the air straighteners to see if they were bent or broken?

[shpankey]

I didn't. Unfortunately I'm not sure i know what it's supposed to look like in there. Are there any pics on the web or does someone have a pic of how it's supposed to look? The thing is tho, my SRI worked fine for a great many months... it wasn't until I added the Cobb TIP to it that it became a problem. I'm sure If I put the SRI back on and put a stock TIP on it, it would run even better. I think it's the combination of the two that is throwing the MAF off so bad using the stock tune.

This really makes me think a Hypertech tune would cure all my ills. At least as far as the wavy pulling. I'm not so sure I don't have yet another problem that is causing the dramatic power loss.

I so wish there was a Mazdaspeed person here locally in NE Oklahoma that would let me borrow his stock TIP just to test my theory. I want to put the car back how it was when it ran awesome. Which was a Cobb SRI, stock TIP, Turbosmart BPV and a Street Unit TP and nothing else.

[Sacrilicious]

look at the MAF housing that came with the cobb sri...does it have an H-shaped air straightener inside the pipe? are the fins of the H nicely smooth and perpendicular?

[shpankey]

K. I'll look and take a pic when I get home (it's in my garage at the house) and post some pics here later for you to look at.

I'm going to guess it's probably fine though. I think it has to do with the combination of the Cobb SRI and Cobb TIP together that is throwing the stock tune off so bad.

Anyone willing to mail me a stock TIP if I pay for shipping to and fro? I promise I will take excellent care of it and only use it for one day, to test with. Possibly two (just so I can learn new trims b4 testing).

[Sacrilicious]

like i said, it seriously doubt it's the TIP. it just doesn't really affect things much at all. unless the cobb sri->tip coupler is screwed up, i don't see how you're going to induce trouble with a TIP, since it's just such a minimal mod to begin with.

[shpankey]

Yeah I know you're probably right. It's just me wanting to return it to EXACTLY how it was before the problems started and see if the car returns. Then from there do 1 mod at a time.

[Sacrilicious]

ya, that's the best way to do it...one variable at a time, but in the case of the turbo inlet, i'd actually be more inclined to say that the cobb one is better for the car than the stocker...the stocker came right off in my hand when i got to it. if it wasn't already leaking at the joints, then it was damn close to it...=/

[mikeywalnuts89]

Thanks for the info

[802_Anthony]

Going back to the original post here:

First off it's a great explanation and it makes sense. I just want to share what I have always thought to be the reason for running rich with a VTA blow off valve.. I'm a noob and hardly know anything about this stuff but if someone can either support this or tell me why it's wrong that would be nice.

Anyway what I've always thought is that because a VTA valve doesn't recirculate the air back to the intake (downstream the MAF), then the car must be getting LESS air than it thinks because it must be calculating for the expected air recirculation to the inlet pipe. Since this is downstream from the MAF this is why I assume it calculates/predicts some amount of air going into the turbo that the MAF hasn't accounted for. Of course I may be wrong if it goes by some reading past the BOV near the intake manifold (I don't know. Noob here, remember?).

So if it's getting less air than it thinks then it's still injecting fuel as if the air is being recirculated, therefore running richer than with the stock valve and thus the backfires and such.

Hopefully what I'm trying to say makes some sense and someone can tell me why I'm [probably] wrong.

Thanks!

[Sacrilicious]

no, you're perfectly right about the VTA. you're getting rid of air that's already been accounted for by the MAF, and just dumping it. less air + same amount of fuel = rich as hell. this is why cars running VTA (or even 50/50) either backfire or at least burble when their BOV goes off.

[I Love Brownies]

I run vta with no adverse side effects. im also catless so i backfire as is. Running vta only causes your afr ratio to maybe change by .1 or so which is nothing. i see no harm in running vta

[Sacrilicious]

if you're already catless, you're going to have a harder time telling the difference between backfires added by VTA. when are you only running 0.1 AFR difference? if it's between shifts, i have a hard time believing that the difference would only be 0.1 after a hard shift. unless your BOV is barely releasing any air, it's going to be a lot richer than 0.1 on a hard shift.

and yes, i've done plenty of testing, and it does make a noticeable difference. most people just get used to the roughness that is added from running VTA or 50/50, and they don't even notice it until they go back to recirc again.

[jracer]

my LTFTS started creeping up.. ( they are usually -4-5 at idle ) but they where getting -8-10 at idle..
so i cleaned my MAF and then serviced my forge.. it was pretty dry .
so i cleaned it up and greased it, and reset my ECU..
back at -4 LTFTS..
So what i have gathered from the first post, spring pressure can affect LTFTS.. and i guess a dry/dirty valve can act like a harder spring ??
causing your LTFTS to change ?
note to self service your valve more often !

[Sacrilicious]

yes, both a dirty MAF and unserviced valve can have the same effect and cause your LTFTs to rise over time. in my experience, idle LTFTs are where you normally see it first, so your experience is definitely not strange.

[NCZ13]

Can ambient temperature affect LTFTs? Im using an ultragauge to monitor my engine as of now, and with the recent cali heatwave, I was seeing intake temps at 145-160 in traffic. ECTs were definitely in the 200s just due to not moving. Needless to say it was hot in the bay.

Mods are
CPE nano
SSQV2
PG TIP
Exhaust depot FMIC
SU test pipe

I know the FMIC isnt helping my ECTs at all.

What I noticed with my LTFTs is that they just kept creeping up. I was seeing 10.XX at idle, and between 7-9 at idle and partial throttle. Ive had 5.47 at idle. Rarely do I ever see it go negative.

I think currently my idle is 5.47 and my partial throttle is 3.19

Any ideas? I have KMD internals I need to install. And I really want to get an AP to get a tune on this car.

but the jump in LTFTs only seemed to be recently with the increase in weather temps.

[Sacrilicious]

yes, i have definitely noticed that hot temps can easily kick up idle LTFTs by 3-5%. this isn't a big deal, since it minimally affects moderate/heavy throttle LTFTs.

[NCZ13]

What LTFTs do I not want to see?

Im guessing double digits in the normal temps?

As much as I love my ssqv and my fmic, I think these two mods are the ones most adversely affecting my car. I too get a nice POP on some shifts, and backfires are definitely the norm.

My recirc line is also starting to tear where it meets the ssqv, I was thinking about getting that CPE flex hose, only downside is that it is 65 dollars.

[Sacrilicious]

at idle, you can pretty much get away with murder. just as long as your LTFTs stay below 15%, i honestly wouldn't care. when you get into heavy throttle LTFTs, though, i'd be looking to keep those below 8% if possible.

am i right in assuming that you don't have an AP yet? if not, you really need to get one and dial your shit in yourself!

as for the SSQV...as long as you're not running it VTA, you shouldn't be getting issues from that. if you're paranoid that something weird is happening, just swap back to stock and see how the LTFTs behave after like 20-30 miles.

[NCZ13]

Thanks for your time dude. Ap is definitely coming soon for sure

[Sacrilicious]

np...in the meantime, just pay attention to your heavy throttle LTFTs.

btw...CBM 4tmfw!

[CWP_MS3]

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