Classic Impreza with some engine issues!
 

Hi all, really hoping someone can help me here.

Up until a few weeks ago (when the weather got really cold) my GC8 (1998 Turbo 2000) has been absolutely fine. Recently, it's had an issue where the upon starting the engine, it immediately cuts out. Turn the key again and it fires up fine and off we go.

Then it left me stranded. Engine wouldn't turn on (but would crank). Eventually through some persuasion (slightly putting my foot on the accelerator while turning the key) it sprung to life and got me home.

Now, it starts really reluctantly. It often dies in the process of starting, but will eventually start every time, however I've noticed a few new things:

1) The radiator fan spins at full speed on cold start. It never did this before, only coming on when the car got up to temperature.

2) The boost gauge shows me that the pressure never exceeds zero, and I've lost that distinctive blowoff sound as a result of it not blowing anything off.

I'm obviously not taking any trips in the car right now because I can't quite trust it (and don't want to damage it any more) so any advice would be greatly appreciated, especially if this is a common thing although I had a quick search and couldn't come up with anything.

Cheers everyone!

Check all boost and vacuum piping and also ect sensor. Any EML?

Hi all!

Turns out my MAF sensor was buggered. Connected the plugs under the dash and read the codes and I had 3:

Coolant Sensor malfunction
MAF sensor malfunction
Immobiliser system malfunction

Bought a replacement MAF sensor from Autodoc and waited over 2 weeks to get it. I had to go for an aftermarket (Ridex) part as the OEM Subaru ones seem to either be hens teeth or incredibly expensive! I opted for the extended return policy which gives me a years extra protection and a replacement if it fails in that time so we'll see how it goes!

The car not starting at all was likely the immobiliser issue, I've heard that these cars are susceptible to radio interference which could cause the tag to not be recognised by the car and prevent it starting. I haven't had the issue resurface yet, so I'll just go with the flow for now.

Replacing the other sensors seemed to fix both long standing issues I've had with the car:

The inconsistent idle caused by the malfunctioning coolant sensor.

The rough, reluctant starts caused by the malfunctioning MAF sensor.

The car now starts perfectly and has that beautiful, consistent idle that it should have.

I don't seem to be getting the occasional backfire at high RPMs either anymore which is good news even though I think the occasional pop and bang adds to the experience but I get enough of that from my M2!

The battery died during the wait (and recent cold snap) so I couldn't reset the ECU the proper way, but the check engine light is banished and for now, that's good enough!

Closing the loop on this one now in the hopes that some poor soul in the future suffering the same thing has an idea of what the fix might be!

Happy new years everyone