gotboost?17

iTrader: (46)

hey guys, having a little problem that's been getting worse latly, when im cruising around 2k rpm (Only around 2k it happens) the car bucks/light jerk a couple times an a/f gauge jumps when it does this, for a example a/f at 14.7 then instanty to 15.7 when it bucks and then back to 14.7, happens at least once everytime i drive now, no cels, i was thinkin 02 or maf, what do u guys think?

Thanks

RomeDiggy

What mods?

shroogis

iTrader: (1)

Mine just started doing this too. In my case, I think it's because Vince and I are still trying to dial my LTFT's in...they are still quite a bit off. What do your trims look like?

umrdyldo

iTrader: (1)

Maybe MAP sensor as well.

Kyle09TC

iTrader: (1)

im trying to dial in my fuel trims as well with trifecta and mine is acting a little funny sometimes

gotboost?17

iTrader: (46)

im catless, trifecta/stg , not sure on the fuel terms, ill take a look at a log, and ths has been doing it for a wial, just real bad the last few days

gotboost?17

iTrader: (46)

ill start off with a maf since mongo has them pretty cheap, and I believe if a MAP in the charge pipe is shot I wont have a inlet reading and if the Map on the intake mani is shot I wont have a boost readiing( I have a rpd), so I bilve that's out of the questions, and the 02's probley have about 30k on them, lmy code reader dint pull any cels, but ill try trifectas reader tonight, anymore imput?~?

an it does it stage tune an trifecta tune, so I cant see that being my problem

shroogis

iTrader: (1)

Mine does it on Trifecta and "GMS1". From what I understand, it doesn't actually switch to the REAL GM tune, it just switches certain tables to GM mimic'd tables (AFR, Boost, timing, etc). Meaning his MAF calibration is the same between tunes and that's why it's behaving the same on both.

I flashed one of my older tunes which had better trims (but too aggressive of timing), and it drove perfectly.

gotboost?17

iTrader: (46)

ill try that but If I remember correct it did it, ill just reload stock

SSCOBALTSS07

iTrader: (10)

U need a new tob/slave lol jk that would suck for u lol

LNFTX

Check the evap/purge solinoid on th intake manifold I had issues similar to yours before I had trouble filling with gas or a cel

gotboost?17

iTrader: (46)

I remember my old tuner unplugged it before to check something, what should I be looking for?

k ill return your money :-P

Stamina

I have been having this problem too. I'll be cruising at a constant speed, and it'll buck or shudder. It'll suddenly drop and immediately reapply like 5-20* timing for a split second.

- Evap is disabled
- Have new cam phaser solenoids, cam sensors, crank sensor, stock and gapped sparkplugs, and O2 sensor.
- It does it even after cleaning the MAF and MAPs, switching with another MAF, switching a new coil pack around, and on a completely stock tune.
- AFR, phasers, MAP pressure, and throttle body position don't show signs of jumping.
- Relevant wiring was checked and appeared okay. Fuel rail pressure is okay. No codes.

My only guess was that it wasn't taking well to the Fidanza flywheel or that I had one or more injectors that were about to go out. Then I recently had a TOB/slave failure.

Rissa

Don't take this as mean but it's while not wial. Sorry it was driving me crazy. Carry on lol.

gotboost?17

iTrader: (46)

ok so i threw stock tune on for the day an it did it very light jerks, threw the tune back on an went for a 30min city drive an nothing so far, an your problem sounds like mine, cruise control or not, i found it does it nicely 4th gear about 1900rpm, so u your problems still on going?

gotboost?17

iTrader: (46)

an thanks for the english class lol

Stamina

Yeah, mine will do it at the same RPM range that yours does, and only at light throttle. As I get closer to getting into boost or actually get into boost, there are no issues. The interesting thing I've found though is that it doesn't seem to do it as much or as bad when there's more gas (weight) in the car, or when there are more people in the car than just me. It also started doing it more after the ZFR turbo swap. Therefore it seems like it's possibly related to engine load.

Nope, I still haven't figure out the cause. When my TOB went out it kinda stopped the troubleshooting until I can fix it. Then what was just fixing a TOB ended up turning into a built F40 six speed conversion. lol I figured if I'm already basically doing the work to drop a tranny to get to and replace the TOB, I might as well stick something awesome back in there. lol

gotboost?17

iTrader: (46)

okay ill keep an eye on the gas situation etc., car still hasn't done it since I reloaded tune, an I believe I have 5/8-3/4,like last yeah when I first noticed this issue I thought it was bad gas, casue I did notice it a lot after leaving a gas station after filling up

and that's sick your doing the conversion, I just got a new tranny threw warranty so threw a ky stage 3 and TOB in at no charge

LNFTX

Are you sure that your purge system is right that is a symptom of bad purge valve
fill with gas all that extra air and vapor had no where to go

gotboost?17

iTrader: (46)

how can I test that? an where abouts is it if soo

LNFTX

Watch this short video

gotboost?17

iTrader: (46)

okay thanks ill try that out today

gotboost?17

iTrader: (46)

evap is good

gotboost?17

iTrader: (46)

well tonight I got a p2096 which is most likely my catless, but also my a/f was reading no data, isn't that symptoms of a bad maf or map?

DSmastery

iTrader: (5)

I'm just gonna throw this out there. When I drive at say 25mph in 3rd

If my foot is in about the center of the accelator it has bucked as few times

Like I'm not on and back on. If I adjust down its fine. Similar affect from a stop to go

I was thinking a small leak on the header is messing with my pedal response.

But it does it a lot at consistent speeds as I was like my foot is barely on it.

Could be a dirty sensor or some hoses need replacing