ccamgem

Hi all,

I have a problem with my hawkeye wrx.

When you accelerate hard the car doesn't see to pull as hard as it should.

When you accelerate Slowly, the car seems to stutter at around 2000 rpm an then power seems down. Not a big loss in power but feels around 25% ish.

The same think happened about 2 months ago so I cleaned the boost solenoid and this seemed to clear it for a couple of months, but is now back, but does this sound like a solenoid failing?

Thanks.

ccamgem

I do have Romraider so can do some logging if anyone can help....

Thanks

Chris

matth76

Sounds exactly like mine, same symptoms etc! Mine is intermittent and normally when the car is cold. No fault codes nothing. No engine lights, no smells, no noise. Just intermittent hesitation as you described every now and then especially when cold, although has happened once while driving when it was warm, and also happened consistently for two days then cleared up. And I have been assured by a specialist it is not a mechanical issue (ruling out pistons ringlands etc thankfully) as the problem would be consistently there which mine is not so not sure what the problem is. Subaru main dealer useless as always and nobody's been able to offer any help . My car has been recently remapped but my map is all ok, no retarding of ignition or boost apparently which is strange as I'd have thought that would cause the symptoms.

I'm personally putting it down to tired spark plugs (although no-one can say yes or no this is a likely cause) as mine have never been done and car's done 31k miles. Subaru change them at 60k miles which is rediculous! None of the specialists have mentioned it could be my boost solenoid. This issue shouldn't be happening in four or five year old cars. However in most cars spark plugs are changed a lot more regularly than 30k miles, let alone on a high performance car so I'm assuming this is the clear suspect.

ccamgem

Mine was fine for ages also. It Seems to be after I haven't driven the car for a couple of days -maybe just a coincidence?

My sparkplugs are around 25k miles old so worth a try as a starting point. I've also asked my tuner if he can look at some log files I'm going to get so will keep you posted on what the outcome is.

Let me know how you get on.

ccamgem

I took it to a local garage today and they advised me that is was getting some negative knock under low load around 2000 rpm. They reset the ecu and then the car was fine but have advised that it's a faulty knock sensor.

So at least it's working for now and have advise that if and when it comes back to take it in and get the knock sensor changed.

Hopefully this helps you out?

Chris

stanmo

iTrader: (1)

I get the same problem with my MY05 JDM car. Hesitation around 2k when cold, my LC-1/AFR meter shows lean for a moment, then it gets corrected. Obviously, I'm not giving it any load at this point.

It started over the cold winter, just had spark plugs changed (2 years old, after engine rebuild last Aug), the problem is less pronounced, but hasn't gone away.

I occasionally get pops from the exhaust, once warmed up, so could be overfuelling too.

I've just got Delta Dash, and am working my way round the features and figuring out what everything means before trying to log everything.

I'll have to look at the knock correction figures (negative means retarding the ignition, right?) - thanks for the lead.

dynamix

iTrader: (3)

If you are going to be datalogging it make sure you log the correct fields for the knock correction. If you log coarse correction (or feedback correction on some software) and fine correction (or fine learning correction on some software) it will show what you need it to show. The field that is listed as 'knock correction' is actually the additional advance that is added by the ecu and will always be a positive figure so may kid you into thinking there is no correction going on.

ccamgem

Yes negative knock means the engine will retard the timing I believe.

I'm getting my spark plugs done at the same time also, not been changed for two years I believe, about 25k miles.

I'll let you know how I get on.

andy.downes

iTrader: (1)

Sorry to hijack - you've had 'just' a remap? What are you running now and how does it feel? Wondering about remapping the hawk but can't afford new exhaust etc !
Cheers,
Andy

ccamgem

Hi,

I Just had remap, and then put on an uprated Walbro 255 pump (£100 ish) and Samco hose set (£100 is again). I got a local garage to fit mine and are really just for safety rather than anything else - got it tweaked after this; but best to do before, you get it mapped.

I have the number and an E-mail of the guy I use, he Charges around £300 for an open source map (Andrew Carr) but mainly works north of nottingham/leicester. He’s also mapped my Forester S-Turbo with a TD04, sports cat, centre de-cat and H&S and this is great - the noise out the back is NICE espically 270/80 bhp from a real sleeper!

Anyway, remapping makes the Hawkeye feel smoother and you will also find you need to change gear less. It gives it about 270bhp and with approx. 310 lb. Torque. It pulls very well in ANY gear, but you really notice the difference in 4th and 5th.

I would say that it makes the car feel much better and you will notice the difference from standard…

Well worth it.

andy.downes

iTrader: (1)

Sounds really good. Much of a drop in economy?

Lenny.

I have similar problem in my 05 STI. At 3800rpm on minimal boost the engine stutters. Intermittent fault, worse when car is cold, can happen anywhere in gear range. Took it to local dealer, MAF sensor replaced, problem still there. Reading some of the Scoobynet posts is it worth replacing boost solenoid? 2 dealers I have spoken to say no but don't know what the problem is.....

ccamgem

Economy is around the same, but it depends on how you drive it.

If you've got more, you use more....

ccamgem

Is there a local Subaru specialist around who can have it on a Laptop to diagnose it? That would be my first port of call - or get rom raider and a cable from Tactrix and ask the guys on this forum to take a look at your logs. You could try a new Knock Sensor but without any logging, you won't know fully whats going on.....

Chris

MrNoisy

iTrader: (28)

Definitely check your plugs and / or gapping of plugs those of you who are complaining about what sound like flat spots or drops in performance at a certain point in the rev range.

With mine, I had acceleration, then all of sudden it would feel like the car had driven into a tar pit - there would be a flat spot just after 3-4k RPM, and then it would pick up again.
MAF sensor is commonly (incorrectly) pointed at - I believe they're a tad tougher on newage than they were on the classics, but unless I'm mistaken I'd expect the car to idle badly too and throughout the rev range if that was screwed.
dynamix would probably be able to confirm that (either that or he can tell me I'm talking nonsense and I'll learn something new!)

On mine, I changed the plugs, gapped to 0.65mm, problem went away.
If you know the plugs haven't been done for a while that's where I'd start, especially given it's a job you can do yourself.
HTH

ccamgem

- UPDATE -


[I took the car to Roger Clark and they replaced the Knock sensor and also the Sparkplugs.

It has made no difference to the way the car drives........they said it could be the map, so I have the mapper looking at it, but surely a Map wouldn’t have an intermittent fault that came and then went away again would it???

Feels to me like a sensor issue as a couple of weeks ago, it came on while driving back from the station, and halfway through a 40 minute drive, the car came back to normal again.

Any Ideas, I'm a bit unhappy about the £360 wasted

ccamgem

I have checked the neutral position switch in Romraider and it is working fine.

Is there anything else I could check?

Lenny.

Thanks Chris. Have found someone with a laptop and rolling road so with a bit of luck they'll be able to find out what's going on. I'll keep you updated.

ccamgem

In December I did get a P0335 - Crankshaft Pos Sensor A malunfction.

I cleared it and then in February I start to get hesitation issues on an intermitant basis.

Could these be related??

Thanks,

Chris

Lenny.

Took the Scoob to someone that came highly recommended.

He suggested spark plugs could be the problem. Replaced them, no difference.

He reckons next thing is to change the coil packs. Maybe 1 or more in 4 is faulty but would cost £500 to replace them all.

I don't really want to be spending money +++

Any ideas, anyone??

Thanks

scottydog137

iTrader: (2)

Coolant temp sensor ?

Lenny.

How can I tell?

scottydog137

iTrader: (2)

Difficult to diagnose on any car!!