Hi there , as a new subaru owner and just under age 20 i havent been through much cars . saved for it a year and now got it . A subaru impreza GT 2000 modell(5230 swedish miles).. Whats done with it is (claimed by the last owner) pistons ,crank shaft , 3" exhaust from turbo , fuel pump and a Link ecu with LEM . Tho i just think they installed the fuel pump and ECU and exhaust . So now to my question . Im not that into subaru stuff yet but have read some on swedish forums and they claim 19 psi isnt to much for the standard pistons and crankshafts , So im running it at 1.28bar and it runs smooth at 1st and second gear .. then when you flick the third in and floor it my boost drops to about 10 psi when reacing higher rpm“s and then straight back up to 19psi and drops again .. through al high gears also. My taught is the wastegate or the blow of valve? or can it be fuel thats not enough ? Or is it that im running with Lamba ON since it drains scary amounts of fuel ? I have the LEM but a bit scared to change to much if it can cause engine damage. Its mapped at JRM Racing 2002 . If any respond i can post my LEM values if that helps anything . Thanks in advance! // Anders

 

My guess is you're hitting fuel cut or gettive massive detonation and therefore ingition retardation. In gear 1 and 2 you will make less boost than in the higher gears which is why you don't notice it. Try reducing your boost to 1bar or even 0.8 bar and see if the problem goes away.

 

Thanks for the reply , il take it for a test drive later . But the MAP limit is 250kpa and my boost 220-230kpa , wouldnt it cut fuel at 250kpa boost? or would it work if i change from my STD MAP to The race version ? Where the Max. Kpa is 300. This ECU is new for me so if change the MAP would it change Any other fuel / ignition times aswell ? Or if its the massive detonation causing ignition retardation it gets to much fuel right ?

 

Not sure what you mean by MAP limit. Do you mean the highest value that the MAP sensor can read or the maximum value that the ECU allows?

Have you got boost of 220kpa or a MAP value of 220kpa on boost? There is quite a big difference there and any of the two values is too big. Make your MAP target value not more than 100kpa on boost.

The detonation can occur for a number of reasons, one reason being that the fuel octane you're using is too low for that boost pressure or maybe your fuel pump is not supplying enough fuel. In most cases reducing boost will make the problem go away till you're able to get an experienced person to look at the situation.

 

Well 220kpa map value , this is what LINK says "If the map value reaches the map limit a hard limit will be evoked , cutting both fuel and ignition" Dont know if the Map sensor can read more than 255kpa or if i need to change it to use the 300kpa Map setting since the ECU is already programed with 300kpa it should be able to handle it.
got a walbro fuel pump and running 98 octane , but now when u nemtion the car ran better on V-power(99)

In my ECU it reads 100kpa boost on idle .. so its 120kpa boost. On Link Home page it says 220kpa in the LEM (Link enginge managment system) is 17.40 psi and my boost monitor says 17-18psi . And from a Conversion calculator 17.40 psi is 1.2bar of boost.

I read on some tuning parts and they nemtioned the BOV(Blow of valve) only could take 18psi boost on standard , No idea if that where true or not. Since it drops nearly 10 Psi of boost for 1-2 seconds and back up again for a few seconds and drops it maybe cant hold the pressure back ?

Thanks for trying to help me , Sorry for being such a NoobyScooby but we all been there right ?

 

Hi standard bov on that year of car can handle about 1.6 bar boost!!

 

Oh thanks for the info , but i might have found out the problem .. the original map sensor only can take 18 psi boost . Might be the problem , gonna lower the boost like saiklon said and hopefully get it going . Il post the results in a few hours . Thanks for the help , since im new here i appretiate it (got bad english tho)

 

Hmm, not sure how the link ECU works, but don't go changing the map sensor without having a proper remap

[ OT: Valkommen till Scoobynet... Kvarnis pa impreza.nu kanske kan hjalpa ocksa, han mappar val Link har jag for mig? ]

 

Okey tested , and it seems like it was the map sensor. Now its holding constant 15 psi after wastegate base opened . 0-60 mph in about 4.5 sec without revving before takeoff . Happy again! Thanks for your teories and il look that kvarnis up for a new Map Il post some more if i need your help ! Thanks again wohoo