SCU1575

Hi to all!

I've just tried to read my ECU for fault codes for the first time because I still feel that the car is not running smoothly and the only fault that came out is 53! How bad do you guys think about this? as there are few meanings for 53 fault code ! Can I just try to reset the ECU and see if still comes out?

Car is MY98 UK turbo classic.

Cheers!

Splitpin

Error 53 relates purely to the immobiliser and as such, if your car's not running right, this isn't part of the explanation.

Can you describe "not running smoothly" to us in a bit more detail?

SCU1575

Thanks for the reply Splitpin.

Firstly, I just bought the car few weeks ago, it's a standard UK classic turbo MY98 and TBH I'm really new with this kind of motor. This car has a Dawes manual boost controller fitted by the former owner but I think it's overboosting as it can passed 1 bar when on boost.

Secondly, when she's on 3rd or 4th gear and running at low speed, if you take your right foot off the throttle and press it again, she becomes jerky or has very little power as if you need to go to a lower gear.

Thirdly, everytime I start her cold, the rev. needle is hunting between 1500 down to 1000 and eventually settles between 600 - 800 rpm once the water temp. needle is up.

These are just some of my few concerns at the moment mate.

Hopefully you can shed some answers.

Cheers and more power!

Splitpin

Yeah, no doubt "more boost" was the reason the Dawes was fitted in the first place! Standard boost target is 0.9 bar and given the significant safety margins on the standard ECU, 1.0-1.1 bar should be within safe limits, provided the engine and all its sensors are otherwise running on the money. How far past a bar does it go when your foot's down, and does it run up to boost and settle there, or spike above and drop back?

There are a few potential explanations for that sort of behaviour - although as you haven't seen the check engine light it's obviously either an intermittent fault or one that's outside the scope of the error checking system, which could make it a pest to diagnose.

This is largely a question of degree, but what you're describing there doesn't, initially at least, sound overly "wrong". The idle speed is supposed to start high when the engine is stone cold and then drop as the engine comes up to nominal temp, that's normal.

However, I'm not sure whether I'm reading your post the way you meant it. Are you saying that the idle speed is constantly hunting up and down between 1500 and 1000, or whether it starts at 1500 and then slowly and consistently drops?

There are a few possible explanations for your throttle response issue that may or may not be related to some idle instability. Slightly dodgy throttle position sensor might be one explanation, ditto idle speed control valve.

If it's getting on your nerves one option might be to pop the car in front of your nearest good Subaru specialists to see if anything obvious pops out at them. Unfortunately trying to diagnose subtle-sounding issues like this is very, very difficult via the internet - it's pretty much a game of pin the tail on t'donkey.