Hi,

Went to the car this morn to start it, no joy.
The engine turns, fuel rails prime, I have a spark but wont kick.
Is it safe to bump start on a hill or will it not matter?

Limited knowledge and I need it for work in the morn! Helllp!

Its A JDM STI Bug.

Cheers.

 

It could be a blocked fuel filter bloacked air filter blocked cat cam sensor crank sensor temp sensor and so on can you get some one to put it on a code reader.

 

Cheers, ill get an ob reader tomorow see if that tells me anything.

It just happen while sitting for a few hours, annoying.

 

When you ignition on can you hear the fuel pump prime ? If you have a spark you can eliminate a crank sensor fault, temp sensor won't stop it from starting, cam sensor I'm pretty sure won't stop it from starting either, check the air filter don't think it would be totally blocked tho, key on and off a few times to make sure the fuel system is primed,
if it still fails to start you'll have to get it to a garage

 

Fuel is been primed, air filters not blocked, have spark. Mite need to take it to a mechanic.

Could it be the immob? There is a clifford alarm installed in it but its never gave trouble and I wasnt doing anything with the car that mey of knocked or damage something.

 

Possibly immob but normal they will stop it cranking, it's really hard to diagnose any problem without seeing it first hand. Best thing is to get it to someone who knows impreza's, if you have a good spark, fuel there is no reason it shouldn't start, get it booked in to your local specialist. Good luck getting it sorted.

 

Oh does the Bugeye not have the ecu connectors under the dash?

 

Got it started, for a bit of info on another thread. Gave it a few long goes trying, third time lucky.

Does, plugged them in ignition didnt tell me anything.

Cheers anyway guys.

 

If your car is starting but not running propley the crank sensor could be telling it to spark at the wrong time or inject at the wrong time.A faulty temp sensor can stop a car from startin especially when the engine is hot .A faulty temp sensor can cause under fueling overfueling .With moddern engines you cant just guess you need to diagnose carefully.A faulty maf could cause it to run poor.Did your engine light come on when it ran.

 

Could you possibly clear a few of these point up?, in my understanding a crankshaft sensor is an inductive sensor for the ecu to tell it when cylinder 1 is at TDC, how would this have any bearing in spark distribution or injector pulse?
A faulty temp sensor, I have never in all my years heard of a temp sensor stopping an engine starting!
As STI ffy said in the later posts he has checked for ecu codes it didn't show any thing so I'd say the cel was probley not on previous to the issue.

 

Could you possibly clear a few of these point up?, in my understanding a crankshaft sensor is an inductive sensor for the ecu to tell it when cylinder 1 is at TDC, how would this have any bearing in spark distribution,

not sure what your asking but,

ecu takes its reading from the crank sensor to make sure it gives the spark to each cylinder at the correct time, otherwise it wont run.

 

So the ecu controls spark distribution, from the crank signal that I get, injector pulse from the crank I don't, if the car runs it can't be a faulty crank sensor, I'm just tryin to clarify for the OP his original concern. Can anyone explain how a faulty temp sensor will stop the engine running ?

 

temp gauge will tell the ecu weather to use the cold start injector, dumps in more fuel on cold to help it start, if the engine is hot but the temp sensor says cold it will just flood the engine by dumping too much fuel in.

 

not sure about injector pulse mate, cant quite remember, think it does the same job, tells the injectors when to squirt the fuel at the right time, but not 100% on this,

hope this helps

 

Crank sensor on these cars does tell the ECU when to spark AND inject fuel - it's just the way the crank sensor/ECU has been designed to work on the... SUBARU!.

CTS is also a sensor that ouputs voltages to the ECU to help with cold starting i.e. acts as a ye olde worlde 'choke'. If it fails, then the voltage could be out of OEM range and it can cause over or underfuelling at start up, which can make it hard to start. Also, it can lead to stalling when slowing to a halt at junctions etc.

I think it's rare for a faulty CTS to prevent a motor from actually starting though (although I guess it's not impossible...)

 

The crank sensor sends a a pulse signal to the ignation module or pcm that is nessary to trigger the ignation coils.Does your car have egr this can stop cars from startin or make them run ruff.Make sure your tps is not not shut stuck.Your cat could be blocked.have you leant any one your car could they have put wrong fuel in of you could have faulty fuel gauge.I have put cars on code readers and no faults have come up but main dealer code readers will pick the fault up.If there is no fault codes it may be a mechanical fault not a electrical.All so check you have good earths.