Stevie B

Just some thoughts if anyone cares to offer.

MY01 WRX, induction kit and full decat from turbo back (magnex downpipe, scoobysport after that) . Was recenty running with the standard cat downpipe in place and running fine (no MAF probs with induction kit at all 10,000 miles worth), but have recently (200miles) replaced downpipe with decat. Now I seem to be experiencing fluctuating boost from 4k revs onwards in 3rd and 4th (most noticable then). The boost seems to 'oscillate' equal and periodic amounts below and above what was normal full boost (on gauge). As you guess I have standard ECU and pipework, I plan to remap, new fuel pump and upgarde pipework required, which I presume would eliminate this problem, as (once again presuming) that the standard ECU cannot hack the increased flow/breathing rate.


I was just wondering if this was 'out of the norm' as the spec currently stands?

Any thoughts are welcome.

Stevie B

The_Judge

I don't think you'd get oscillating boost from decatting the downpipe. Overboost spikes, maybe. Oscillating boost is normally associated with a clogged wastegate solenoid. Give that a clean to begin with (and check your engine oil level). If it's overboosting as well though, you could drill out the restrictor slightly. Or get some sort of manual boost controller to take the wastegate solenoid and restrictor out the equation...

Stevie B

Thanks for the reply.

Mmmm, I am not sure where to start looking let alone tackling the wastegate solenoid. I would be up for having a go though. Any directions?

ZIPPY

Steve, on your drivers side under the bonnet you will see a small piece of plastic with 2 twist clips holding it on (in front of the top of the suspension mount) take this off and you will see 2 black hoses connected to a small cylinder which is held in place by 2 x 10mm nuts,remove these and dont drop them into the engine bay,the cylinder will pull off from the mount.
Remove the 2 pipes (remember which way they came off) now you will have the Boost Solenoid off, spray lots of brake cleaner into both openings of the solenoid several times.

Shake it dry and then re-fit it and all should be fine.

Zippy

Stevie B

Cheers Zippy!

The_Judge

Here's a piccy. It's the small blue cylindrical chappy with a blue connector, underneath 1. Driver strut tower...

Stevie B

Hi Guys,

Thanks for your help. I have cleaned the solenoid and the oil I have just changed. Still seems to be running off song. I shall be doing a few miles this weekend so I will see how it goes. Drilling the restrictor sounds a 'interesting'.

Looking on the overboost thread there was mentioned about cleaning the restrictor with some break cleaner?

If the problem still exisits could you tell me how to do that (if you recommend)?

Thanks once again guys,

Stevie B

The_Judge

Did you initiate ECU diagnostic mode first?

What level is it at?

Assuming you have a similar hose layout to mine (MY00), here's a picture of the hose in question. If you remove the hose to the right of the T-piece, the restrictor should be just to the right of where it connects to the T-piece. There will be a slight bulge in the hose where it is. Spray loads of brake cleaner down there.

Stevie B

[QUOTE=The_Judge]Did you initiate ECU diagnostic mode first?

No, I did not. How is this done (I must sound like a right muppet!)

Stevie B

Hi Judge,

Cleaned the restrictor, off away for the weekend now, so I will see how I get on and let you know when I come back.

Thank you very much indeed to for help (I presume you work on scooby's?)

Regards,

Steve

The_Judge

Ahh bugger, yours is a bugeye isn't it? I'm not actually sure how you initiate diagnostic mode on those, if at all you can, as you don't have the connectors beneath the steering column...

You're welcome, although I'm not sure how much I've helped you!

Only my own...

Stevie B

Hi Judge,

Well, the boost wall still playing up over the weekend, it went in for a service on monday so I thought I ought to put the standard air box back on and things have seemed to of cleared up. However, the engine light has now gone off (was not expecting this as have full decat from turbo back and was on constantly before) so I preume they may have re-set the ECU. I will fit the induction kit again this weekend and see how I get on. As it does go a bit quiker and sounds much better with industion kit on.

Cheers for now,

Steve