Hesitation!!

I'm getting a hesitation when I take off or when I'm cruising and then mash the gas. It also does not seem as if the boost is spooling quite as fast and its really not maxing out where it should. Any suggestions? I have not made any mods to my engine lately with the exception of a Hyperflow tmic.

 

bad gas? Try resetting your ecu. Also going from a stock size TM to a big TM like the hyperflow you should get some tuning done. You could be ruinning lean.

 

I've always felt a little hesitation when I mash the gas on cruise control but I always thought it was just something in the electronic throttle. But I guess in your case it must be something else. (you have a cable throttle right??)

 

i would do a once over on all vac lines around the turbo area. the one that connects from the boost soli to the wastegate can get quite brittle with all the heat in that area. its a start anyways.

*edit kris is right tuning will probably clear this up.

 

Its summertime. My car feels a little slugish if I have been driving it for a while in the heat.

 

i second the summertime suggestion... i can notice a big difference in how my car pulls during the day and at night

 

as long as the engine light isn't on I would do exactly what JTmoney and weapon wrx said to do.

 

thanks, *the lines are fine, they were just replaced recently and I looked them over on the weekend. *Its not the weather because it was doing the same thing at night and during the day. I actually was expecting some weather responses; so good try...lol. *I do need a re-tune that's for sure, but it was running great last week.
*As far as the gas issue that had crossed my mind also as I ran some Kroger gas of all things instead of my usual BP or QT, who knows.
*My check engine light is on because of a cooling fan issue, but I'm working on that and haven't been in any traffic to overheat it.
I'm going to put some booster in there along with some complete gas treatment and see if that helps.
Thanks for the input so far

 

i doubt the bigger TMIC would make it feel sluggish without tuning... if anything i would expect it to overboost and run a little lean... then again, im no tuner

see if u can get a hold of a logger and log your car... might just be bad gas that brought the advance multiplier down

 

Stupid question time, but why would a bigger TMIC cause a lean condition? I've heard this several times but I can't figure out why... the MAF should be metering all the air and adding fuel accordingly, so what am I missing in the equation?

 

If I can get fan problem out of the way I'm going to save up for a tune with Scott S. I feel like my car is a hodge podge of upgrades right now and need to get it running right. hmmmmmmmm never had this problem before I joined wrxatlanta, my car ran great stock....lol

 

good question... i never really thought about the MAF metering the air... maybe there's a scaling issue? maybe someone who knows will chime in

 

Actually everything here is a possibility. Moose is correct that more flow doesn't directly cause a lean condition; the maf sees more air, then sprays more fuel...

HOWEVER, Milo is also right that it "could" cause it to go lean because the stock scaling ends at 2.5 grams/sec/rev. Overboosting can put it off the table... what happens out there "off the table" could cause a lean condition.

I would say that the car might be "mad" as in it has yanked the AM a bit, and now is running less timing...

see if you can get some data...

SS

 

timing was my next thought but don't know how to do timing, anyone out there want to help?

 

good question! thats what I thought also! I put a bigger intercooler in my 04 wrx and it didnt change a thing except for cooling capacity, I think.

 

what intercooler did u upgrade to? was it the STI TMIC or a bigger bar and plate?... the STi intercooler has a greater cooling capacity than the stock WRX IC but i don't think there's much change in the pressure drop... on the other hand, the big bar and plate ICs have a much lower pressure drop

 

I think I have the same as you milo, I have the Hyperflow tmic. Its been running fine until now.
on the way home the car felt so sluggish and would hesitate and backfire occasionally. Hesitations when I pressed the gas and then when I let off it would kind of buck.

 

poison pill

dont forget the poison pill (restrictor)

 

i would recommend data logging it to see what exactly is going on

 

how would I go about doing that?

 

find someone with delta dash or TARI... TARI is free but u need a cable to use it... so maybe u could download TARI and borrow an accessport owners cable

 

you are speakin' Greek to me....I'll just post up a help thread...lol

 

Basically, you need a friendly soul with datalogging software and a cable to log what your car is doing and then look at the resulting file which might help indicate what's wrong.

 

hopefully someone reading this thread would be willing to log your car for you... i think thats the best way to start diagnosing the problem

 

hopefully, thanks again

 

Tari is free and works great but is a pain to get set up right. You have to have a cable as well. My buddy has a Cobb Accessport and I use his cable when ever I want to datalog.

 

sounds like he might have a bad coil pack, spark plug is fowling out, just my 2 cents.

 

see this thread for answer: http://www.wrxatlanta.com/forums/showthread.php?t=7396

 

Cool man glad to see it was something very simple I will have to remember this.