Hi everyone looking for some help my car has developed a fault. I have a 2006 Subaru WRX.

On starting my car, it started normally then approx 10 seconds after running it’s started to idle erratically high then cut out. On starting the car again does the same thing. Car will not idle properly and is not drivable.

Had AA out said fuel and the pump are working but he couldn’t identify the fault, so I’m hoping any fellow Scooby owners have had the same problem would know the issue.

Others have said it could be MAF sensor, or loose/cracked hoses but all seem fine, I will try to upload a video if needed.

There are no engine codes showing up, so any help appreciated with what I should be looking for.

 

Hello
Try unplugging the maf then start it , and when it's running unplug the maf , if no change then not the maf , other things intake air leak , fuel pump failing , can you hear the fuel pump on start up ? You can buy a little gauge and test the fuel pressure , cam or crank sensor , even a weak battery or alarm issue , local scooby dealer near you , try and get it plugged in 👍

 

Even without engine codes, this type of problem is often related to a faulty air/fuel sensor, an air leak, or a dirty throttle body. Simple checks include the MAF sensor, hoses, and idle speed.

 

Thankyou for all your help very much appreciated.

 

Clean your idle control valve.

 

Buy gasket before touching idle control valve

 

good luck finding an idle control valve if its a 2.5 wrx

 

One more reason to not buy 2.5l

 

I'd make a list of things you can check without disturbing any gaskets or buying anything 1st. If its cutting out so quickly its losing or getting too much of one of the 3 things it needs. (Not enough air = MAF, too much = Air leak, not enough fuel = pump, too much fuel = dodgy injector or poor spark) I'd ignore the ignition system for the time being as when it starts to fail it does so under load. Sensors and coil packs etc. tend to generate fault codes before failing completely. You dont want to buy a load of stuff you dont need, especially when your car is making it clear you are gonna have to spend some money!

I'd try unplugging the MAF as VXR suggested. Sounds like it to me, especially this time of year!

Does the fuel pump cut out? Poor connections at the pump, twisted or split lines can cause it to stutter. The car runs while it uses the fuel in the rail then tries to cut out. Its not really a 'Subaru' problem but again, its an easy thing to check without taking anything apart.

Another easy thing to try before removing anything major is to disconnect the intake pipe and cover the hole with your hand an a rag. Car should initially try to cut out! if it doesnt then air is getting into the engine somewhere it shouldnt. A leaking hose or failed gasket usually.

Could be an immobiliser issue, does the immobiliser light follow the usual sequence? Remember, alarm/immobiliser systems are fitted after the car was made so wont generate fault codes

Finally, when it starts does anything come out the exhaust? Can you feel anything? Pressure? Smoke? Again, not necessarily a Subaru specific thing but when catalytic converters break up they can block the exhaust. If there is no pressure coming out the exhaust it may be worth removing the front O2 sensor and checking to see if it will start.

Have you had work done on the car recently? Is this a sudden fault or has the car been hinting about a problem for a while?

Work out what does and doesnt work and you will know where to focus. Easy!