miza

2002 wrx ,112000 miles no mods except ninja2 back box so far

this is my first Scooby and its not running that great. around 4000 to 4500 rpm I get hesitation, then boosting as normal. had the car for 2 months now and all seemed good up until now. there as always been a slight hesitation before coming on to boost but it didn't really feel that bad and thought was prob just how the car goes. recently have been getting a much more noticable hesitation and a flashing cel (10secs) after but dosnt stay on for me to check codes.

I have got a vagcom cable and have romraider set up.
I have been looking at the parameters but not been able to make a lot of sense as to wht going on.

things I have noticed

whilst idling there is a slight misfire kind of, and at same time I get a positive on the knocking signal (?)

at wot or close to as you get too near redline(6k plus) and then change gear, there is a rattle grinding pinging sound

have checked the manifold relative pressure direct and idles at -19 to -20 and have checked boost and have had boost of 13.6 psi

my air fuel ratio is at 14.7 ...... max 25.24 and min 11.25

my iam has been real low at 5 recently , I cleaned maf and clean boost control solenoid and hoses , checked for leaks but found nothing . sinse then I now have a iam of 16 .

thought that I solved it but the hesitation is still there

other stuff I have managed to log

a/f learning 1a (stored) ... -14.77
target boost is around 13.61 and max 20.09 and min 9.84
turbo dynamics -3.40 max 3.47 and min -5.00
ignition total timing 9.50 max 20.00 and min 6.50

I plan to go out this eve and do some proper logs but am new to this so any help would be appreciated.

have done alot of research and have learned it could be a few differnet things spark plugs, boost leak , vacuum leak , 02 sensor, exhaust leak , dodgy turbo , coils , bcs ,

im just looking for some guidance as I am the type of guy who likes to do things myself but don't really have any experience, so find it easier when get a push in right direction , just knowing that I am doing the correct things gives me the confidence to do it lol

I am by no means mechanically minded but have always looked after my motors and learned along the way, have already learned a greayt deal about the Scooby ,

any help would be greatly appreciated ( sorry for long post, I have checked all forums but there is too much info for me work with) it could be anything lol

thanks

timing belt will be change in next 2 weeks as not sure when last done (is there any way to check timing on romraider ? )

Ed-EG

This sounds like a similar issue to what I had with mine, where the map on the ecu wasn't suited to the fuel injectors. Check how much the ecu is adjusting the fuel injection duty cycle by, the maximum it can learn to is +/-15% I believe, and then it can adjust further on the fly depending on how rich/lean it's running. Failing that check how the turbo is coming on boost?

Of course the issue for me was caused by having a standard map put on a WRX that had a bigger turbo and bigger injectors, but that's another story

MrNoisy

iTrader: (28)

In regards to the CEL - if you have a VAG cable then you should be able to determine what the fault code is, but you haven't listed it.
Subaru fault codes are normally fairly self explanatory, so do a search, see what the code is and then let us know and we will probably be able to point you in the right direction

If you're certain you're getting knock and the CEL is on drive it off boost to avoid more det in your engine, if you know you're getting knock don't carry on driving it with yer foot down.

Get it to a respected mapper who can check the car for you and make any necessary adjustments.

miza

Thanks for your replies fellas.

Have checked the codes and shows misfire on cyls 1 2 and 4 .

Took it into local Scooby garage 3 arches Cardiff (not stealers) who were really helpful. We found leak in up pipe so am looking for replacement , was thinking about sti manifold and up pipe (used ) ... Will that require a tune ?

Bought nkg platinum set will fit same time as up pipe .

Would up pipe leak cause misfires?

MrNoisy

iTrader: (28)

The only misfire I ever got was when a coil pack was loose.
I'd start with changing the plugs and then checking the condition of the coil packs when you change them.
If the plugs fixes the running you have your answer.

A leaking up pipe means your car probably won't hold boost properly and may also make the car run lean / too rich so would get that addressed ASAP.
However on its own it won't cause a misfire - that's more likely to be your plugs being in crap condition or a coil pack hasn't been bolted back down properly or has perished.
Get your plugs done first (happy to offer advice here as I've changed my own a few times), and see if the running improves.

Re up pipe, as its a WRX your best bet is to get rid of the original (as it has a cat in it) and install an OEM STI pipe or better still a Harvey up pipe (available from AS Performance) for about £140-150 iirc.
Don't be tempted by any eBay flexi join crap, they ALWAYS break or leak and are poor quality.
Note that the car WILL need mapping after this so if you can stretch to it, replace the down pipe and centre section with sports car / decat items, and get a decent panel filter like Green or K&N in the airbox.
Scoobyspares, scoobybits etc do plenty of full systems second hand and are well worth a call.
With all that fitted, and a decent map will take the car from 215bhp in standard form to 280bhp.

By the way, with poor running, the newage cars very rarely suffer from MAF problems, its more often the classics this effects. Many people on here do a few searches and will instantly tell you that's the problem so do plenty of research!
I've had two of these cars and learned the expensive way with my first one!

miza

Been laid up after surgery on my eyes so Srry for not replying .

Since my last post I have replaced damaged up pipe with Harvey De cat and replaced manifold with sti version but didn't fix the problem .
Have changed maf and o2 sensors still no joy.
Changed plugs and tested coils ... Nothing
Compression test came back fine

I have been reading about the benefits of grounding mod and am now wondering if bad grounds could be the problem ?

No longer gettin misfire codes and the recent system too lean code has gone too .

planning on grounding it all tomorrow as after reading threads about it it seems some people who have had success with it were having the hesitation problems similar to me .

Thanks for ur advice Mr noisy , do u think ground mod could help/resolve this problem ?