gillyz20let

im getting a small hesitation at low revs on low throttle like when pulling out of junction or changing gear when cruising it just seems to stutter at around the 2k-3k mark but picks straight up afterwards and is felt more when engine is cold.

help anyone

s60r

hi,

was getting the same on my new (06) wrx wagon. was about to ring dealer but read on here that bp ultimate wasnt rated. thats all i had been running and it was getting worse and worse when cold on start up, missing, hesitating etc.

no v power near me so went for tesco 99 super and im half way thru the tank and its better already. its still there slightly but no where near as much and improving. so will run another tank thru and see if it goes altogether.

failing that its off to the dealers as i imaginge the plugs arnt right.

what fuel you run?

cheers.

gillyz20let

the guy who i bought the car of 2 weeks ago had been using normal unleaded and the car was really bad when i picked it up, its a lot better now but still has very slight hesitation.

im using v.power.

s60r

hi,

you must have run a couple of tanks thru now so you have got all the improvements youre gonna get. so try cleaning/replacing plugs especially if prob gets better when car is warmed up one may be cracked? pig of a job to get to tho ive heard.... clean maf sensor?

if still bad then consult the pros.

good luck.

gillyz20let

how do you clean maf sensor?

johnnyroper

could be maf sensor problem or front oxygen sensor i have also read something about cleaning out boost solenoid try doing a search for all 3 faults that should bring up some info


what year car you got as maf is different on classics to newage?

gillyz20let

its a late 04 (my05).

Dave19854

Guys, I know it's been like 16 years 🤦‍♂️ but did you actually solve this issue ??
I have the exact same problem with my 06 jdm it's driving me nuts.

hedgecutter

iTrader: (5)

More info needed. Mileage? Modifications? Service intervals/record? Length of ownership?

Dave19854

Hi Hedgecutter.

It's a subaru impreza sti 2006 twin scroll EJ207 (2.0t)
71,000, has been serviced regularly too. Last service and plugs done at 67,000.

Only had it for about 6 weeks, I did feel a very tiny stutter when I bought it however it boosted and pulled so well I thought it was nothing.

Mods
Spec c long runner intake manifold
PRF7B Plugs
Miltek 3" Resonated turbo back exhaust
Mac 3 port solenoid
Walbro 255 fuel pump
Spec c fuel antisurge hanger
Mapped bt Duncan Graham of Race dynamix.
Exedy pink box sports clutch (crap horrible shudder)
Rts chromoly lightweight flywheel.

I've had a subaru guy take a look, changed the maf and iacv, he even put a new map on it which made it a lot worse! so I had it flashed back to Duncans map.

Symptoms!
OK so the idle is rough, sometimes it will rev up and drop, sometimes it will drop and come up, SOMETIMES 🤦‍♂️ it's perfectly sitting at 900/1k.

More importantly though, when I drive (for example) 2nd 2000rpm lightly touching the pedal i can feel like a small miss, a small jurk/stutter. Sometimes a lot worse than others.
When I boot it she's fine 🤷‍♂️
It's a lot worse when cold

2 days ago I put some Wynns injector cleaner in however I didn't really see a difference until yesterday (a day later), it mostly cleared up! I jumped in it this morning with my fingers crossed and yep it was still excellent.
chuffed thinking it is an injector or fuel filter (at least I figured it out) HOWEVER 🤦‍♂️🤦‍♂️
Jumped in it this afternoon and it's creeping back.

Now then!! Something dawned on me!
so yesterday I actually removed the car stereo, 10 miles later the car is running almost sweet 🤔
I also realised that it was running at it's worst with a amp installed, coincidence ?? Hmm maybe.

also when I jumped in it this afternoon i actually picked it up from being tinted (can't open the windows for 3 days) so I had the Airton flat out 🤔🤔🤔

OH I'd say maybe important!
just before it started running properly the revs dropped to 300 at idle (never seen it before) and held there until I gave it a little rev which took it back to 900rpm (normally at 900ish) then she was away 👌

Battery voltage has been tested and tested with the car running, all is good there.

lockheed

iTrader: (1)

Your problem is Duncan Graham he is the laziest mapper in the world.
Try FB tuning.
I could be wrong but I think you can map for ac use or I know I can with my Link g4

Dave19854

Funnily 🤔 this isn't the first thing I've heard about Duncan.
I had it remapped with Dave Coe but it was worse in places so I had it flashed back with Duncans.

I don't think it's the map though as after I put the injector cleaner in it was almost perfect for a day, a completely different car.

I have it booked back in with Dave for a diagnosis and repair on Wednesday. However! It's previously been with him, hence the map, ivac, and maf replacement £1000 later 🤦‍♂️ with no real results.

RobsyUK

iTrader: (2)

Replace the fuel filter for an oem one.
if removing the stereo made things better then check all your earths are good.

Dave19854

Yeah I'm thinking fuel filter or something fuel related 🤔

I'm planning on doing a earth mod but I need to be sure I'm putting the cables in the right place.
I've taken one from the batt earth to the inlet manifold and cleaned the one that goes to the car from the batt.
car mechanics aren't my strong point unfortunately.
the car wasn't cheap so it makes me a little nervous messing with certain things, if it was a 2k car I'd have a different attitude 😅

hedgecutter

iTrader: (5)

As above, earth grounds, potentially lazy mapping, fuel filter, pump, dampers......but I had a hesitation at 80k miles on a wagon, which 3 well known "specialists" failed to diagnose. It was always around 2 to 3000rpm, like a misfire. Wasted alot of dosh on on trying to fix it with them. Then read an article on injector spray patterns and their importance to turbo cars, had injectors cleaned ( 1st ASNU specialist tried scamming me, as there was no before and after readouts, and it turned out they hadn't actually done anything) No further problems and it felt like it had gained 20hp. It's the essential maintenance at 70 to 80k miles that no-one bothers with.
This means being flow tested, baskets changed, electrically checked, ultrasonically cleaned and flow tested again, preferably by an ASNU technician.
Forget cleaners or Terraclean type treatments, physical cleaning and testing is what's required. They're as important as your spark plugs, if not more so.
​​l actually used Injector Cleaner of Devizes on ebay

Dave19854

I appreciate the reply Hedgecutter,
it seems I'm having a very similar or even the same issue. 2-3k i have a hesitation like small miss (worse when cold)
the injector cleaner was more of a trial and error thing, if it helped then it was time to clean even change the injectors exc
Yesterday I left work obsessing over this hesitation (checking if it's still there, is it better, testing with no electronics on exc)
at some point it cleared up a little again and yes I feel as if I have more power, even going up the gears on load feels more responsive.

It's in Wednesday so I'll be sure to update the post as there isn't many threads on this small hesitation especially without a engine light.

Dave19854

New fuel pump & new fuel filter fitted (which was filthy) same issue no fix 🤷‍♂️

im starting to think this is weather related, once i picked the car up Saturday it felt pretty good but has slowly been getting worse.
it's been hammering it down today and I've hit a few deep puddles, it definitely feels a lot worse today.

Do I go plugs and coil pack next,

stamina_daddy

iTrader: (3)

Ha ha 🤣 the Subaru ownership obsession.....is it ok.....will it blow up etc etc.
it's the only brand of car that seems to invoke these feelings.
I just got my old one back after about 6 years and it drives and sounds the same.
I'm 100 % more relaxed this time round.
Happy hunting.
Have you checked for air leaks ,air box lid on properly?

Dave19854

Well I'm not relaxed 😂😂

So new update 🤦‍♂️

Seems the car runs like a dream without the maf plugged in 🤔 first thing I did is buy a brand new maf (even though it had been changed recently)
Unfortunately though No fix 🙄

I feel I'm getting somewhere, it's an air fuel mix problem (I think)
I'm talking! without the maf all issues are solved, no idle issue and no stutter 👌

i'm aware it's not good for the car so it needs fixing, what could it be guys??

stamina_daddy

iTrader: (3)

This.....I've never had problems with my cars after FB tuning maps.
And yes you seem to be chasing your tail and spending money when it could all be in the map of the car.
When I sent a request to FB tuning for a map on a JDM legacy he said it would be hit or miss wether he could do it due to his equipment recognising the JDM ECU .
I didn't bother in the end but what I'm saying is that I think the jdms are a bit more sensitive to remaps and if you're not 100% then these issues your getting could well be down to the remap.
No amount of changing parts will help.
Good luck