Still having issues

[D3ft0n3s]

Ok, so after much money being spent at a mechanic....

My 02 WRX (STANDARD) still has boost issues.

He replaced MAF cause it was leaning out, also replaced faulty boost control solenoid cause it wasnt working well either.

Now what happens is, boosts fine, till about 3000 RPM then its like it hits a flat spot drops a little, to say 10psi, then tries to get back up to 13 again.

He had it on a computer and it has consisten 13psi till around the 3000 mark, then its like the engine retards itself.

Could this be fuel? (he said it could be due to running it on 95 but im not so sure) but i can try 98.

Could it be faulty knock sensor? doesnt throw up any error codes or anything.

Or could it be that it needs re-mapped?

im at the end of my rope, any suggestions would be great. Tested on wastegate only pressure and worked fine.

[twinturboboy]

If you can be bothered, pull out the knock sensor and look at it - even just replace it, they arent too expensive.

[Stoffa]

some one with a proper scan tool should be able to diagnose the issue, sound like it could be a knock issue to me

+1 for changing the knock sensor, if its getting false knock it may be pulling all the timing and going into safe mode but normally the actuators are only 7psi not 10psi so I could be way off

[D3ft0n3s]

can someone tell me where the knock sensor sits?

and idea of cost?

would Armstrong's have proper scan tool?

[twinturboboy]

Have a read of this - dont know if the WRX knock sensors are in the same place tho

http://www.clubsub.org.nz/forum/index.php/topic,23520.msg327509.html#msg327509

[twinturboboy]

Oh and look at this

http://www.trademe.co.nz/motors/car-parts-accessories/subaru/accessories/auction-502690154.htm

[D3ft0n3s]

 twinturboboy said:

Oh and look at this

http://www.trademe.co.nz/motors/car-parts-accessories/subaru/accessories/auction-502690154.htm

If im not getting a CEL from the sensor though, will it be the problem?

Ah bitch and its under the intercooler

[D3ft0n3s]

scanned at Armstrong's. no codes. changed knock sensor didn't help.

it's still at Armstrong's.

any other ideas? ???

[Joker]

maybe, just maybe, as a suggestion, you could keep it all in one thread for the same car rather than having to re-explain every time

moving the knock sensor was all the rage at one point in CS's history (some can be over sensitive)

and my thoughts are it will only throw a code IF its not working/fault in the sensor, not every time it detects knock etc : I think its doing its job fine

(not saying I'm right just an idea)

[D3ft0n3s]

yeah fair enough but this was a fresh issue. and had other bits fixed hence the re explain.

so what should I do now?

[funkytown]

perhaps some time plugged into a dyno tool (v7+ can be remapped) and they can look at whats going on.

might cost you some more $$ but unless you take subaru people and their tool out for a drive to replicate your issues you are unlikely to solve it.

[D3ft0n3s]

 funkytown said:

perhaps some time plugged into a dyno tool (v7+ can be remapped) and they can look at whats going on.

might cost you some more $$ but unless you take subaru people and their tool out for a drive to replicate your issues you are unlikely to solve it.

done the subaru tool way. they also aren't. sure. tried with another knock sensor made no difference.

tool didn't help much

[funkytown]

was it a static scan or while you were out driving replicating the issue?

[D3ft0n3s]

was it a static scan or while you were out driving replicating the issue?

[/quote

tried both mate. he agreed felt flat but tool didn't pick anything abnormal up

[MercuryFree]

Has fuel pressure been checked? If the FPR is faulty or fuel pump dying a bit perhaps it's not delivering enough fuel at high load?

Mine was doing something similar (although not 100% the same) on the dyno in the weekend and the tuner suggested the above as a possible cause.

Tbh I'd also try it on 98 just to rule it out, as that's kind of a simple/cheap thing to try

[D3ft0n3s]

 MercuryFree said:

Has fuel pressure been checked? If the FPR is faulty or fuel pump dying a bit perhaps it's not delivering enough fuel at high load?

Mine was doing something similar (although not 100% the same) on the dyno in the weekend and the tuner suggested the above as a possible cause.

Tbh I'd also try it on 98 just to rule it out, as that's kind of a simple/cheap thing to try

yeap done that apart from Dyno, fuel pressure was checked and was good with proper testing equipment.

I'm at the stage where i reckon its spark plugs, but its not a miss, its just down on power

[D3ft0n3s]

As an update, armstrongs had it all day, tested the knock sensor by changing it for a new one, didnt work. Also checked the cam timing, was all correct.It is going back to them on Saturday morning (first time i can get it in), the worrying thing is, it appears to be getting worse

[Stoffa]

did armstrongs confirm that it is retarding the timing?

if its not it my be a mechanical fault like the turbo having a chip out of the compressor or maybe your cat has collapsed and causing too much back pressure....

hopefully they haven't put the apprentice on the job and it'll get sorted

[D3ft0n3s]

They Reckon its not retarding the timing.

Turbo functionality was checked when i had it in ashburton by a man who builds RX7 race cars, so hopefully he would know.

Backpressure was checked on the scanning tool at armstrongs when i was there, and found to be normal.

The apprentice is not on the job.

Failing fuel pump? Bad spark plugs?

[D3ft0n3s]

A big thanks to Hijacka for finally fixing the problem

[madmike]

what was it?

[KwS]

 madmike said:

what was it?

yeah, damn i hate it when threads end with "fixed!" and no explanation to what it was.

[Guest]

 KwS']

[quote name='madmike said:

what was it?

/quote]

yeah, damn i hate it when threads end with "fixed!" and no explanation to what it was.

+1 countless times ive googled then read a 3yo 6 page thread with no end other than all fixed...

[D3ft0n3s]

Ok sorry, not sure if many cared.

It was a bad fuel pump, when removed it was found to be smaller than standard.

Diagnosed by turning car on, hear it prime, dont start car, turn off, turn car to on, prime'd again, Shouldnt have!

That SHOULD be all fingers crossed

Have a look here :

http://www.trademe.co.nz/Community/MessageBoard/Messages.aspx?id=1092865&p=4&topic=1

hijacka has posted pis of both

[madmike]

Mine always has done exactly that..

All our cars have in fact