Hi guys.. i have a v4 sti and after driving on motorway for a while i noticed it wasnt boosting properly, like it boosts around 5.5/6k rpm (still holds 1.2 bar) , i checked the pipes and turbo seems fine as powet is still there top end. Error code however did come up with idle control valve and maf. Would the Maf most likely be causing this? Cheers and let me know if anyone else experienced this..
ps im new here

 

Im a friend of his, there is also another problem the car is not starting at all now the fuel pump does not prime on ignition would the maf sensor being causing the car to not start?

 

Hi there

Can you please check again for error codes ?
Failed MAF shouldn't cause to fuel pump not priming,yes starting problems or bad idle etc can cause

I would check wiring and MAF etc and please check fuel pump if its OK,fuel pump can fail and what fuel pump he is running?

Thanks,Jura

 

I do engine code check again, the maf wiring is okay even if we disconnect it car still doesnt start

How would you direct the fuel pump from under the rear seat? Or in boot and what wires are live and earth? Its a standard fuel pump

 

If you will disconnect MAF car doesn't start ? Then I would check wiring on the car,I would check coilpacks etc and pump is under rear seats

Do yours car have immobilizer?

Sometimes can immobilizer cause doesn't start or fuel pump relay etc,I would check few bits with multimeter

Thanks,Jura

 

Can you hear the fuel pump priming when you turn on the ignition? If not then I would suspect the pump as broke down. The other cause could be the connector block under the rear seat, these can corrode with age. Make sure you inspect both male and female ends. You can use a multimeter to check.

You could always disconnect the fuel line in the engine bay into the fuel filter and turn the ignition on to see if there is flowinto the filter. Be careful not to squirt fuel everywhere and use a china mug or glass. If there is flow then check the out pipe from the fuel filter, no flow blocked fuel filter. If flow is present another easy check is done.

But check all the connectors and plugs under the bonnet then move on to the relays and fuses. The easy stuff may prove to be the problem.

Just my tuppence worth.