Cross posted in engine 2.5 forum. I just need all the help as possible. Thank you.

2002 WRX

Modifications:2.5 Shortblock, Mahle pistons, HKS GT2540r turbo, super megaflow intake, hks downpipe, uppipe, turboXS UTEC, sti v.7 TMIC, walbro fuel pump, STi pink injectors. 16psi, turbo XS manual boost controller.

Last year I had just a regular ej20 block and got a HKS GT2540r turbo kit installed with the above mods tuned by godspeed with a UTEC. After about two months I began to stall when the engine warmed up after 10 minutes of driving. At first I found that the 02 sensor on the intake was loose so I tightened that and voila, problem gone. However another month went by and the stalling came back. I got the car checked out by a shop and it was recommended that I have a compression test done. Compression test revealed that cylinder 2 was down to 97 (this is the cylinder on the driver's side closest to the headlight). All others are at 150.

Mechanic is thinking either burnt or bent valve. Ok so then I decided to upgrade to a 2.5 block with Mahle pistons. While everything was done I got the heads re-done as well and it was revealed that there was no bent or burnt valve. Put everything back together...

Still stalling after 10 mins of warm up. When cold it doesn't stall.

So in the last 2 days the following has been done to the car:

Replaced the gasket and cleaned the IAC. Also found that my intake was put on using the wrong thread sized screw thread size and the MAF was never fully tightened down so the right screw is now in. Now I have assumed that the MAF would have made a huge problem for idle. Got all of that fixed, Replace the IAC, MAF, MAP and went for a drive. It still dies like I didn’t fix anything. Vacumn is good according to the gauge, it seems though that the ECU seeing the wrong MAP voltage. It seems like it cannot be a mechanical problem as all the mechanical items are new. It is possible it is a bad sensor and there is no code. Unlikely, but possible.

Please help as I have spent over $6000 in repairs this year already. Anythoughts would be appreciated.

 

could be a bad coolant temp sensor. keeping the car rich at all times usually when a coolant temp sensor goes bad the engine thinks its negative 40 out so it dumps the fuel in. thats ok for start when its cold because its not in closed loop so it will run rich but once combustion temps are up taht added fuel will stall the car right out. have someone hook up a scan tool and watch your ect value. sometimes a cel wont set because the computer thinks its doing the right thing by feeding your car all that fuel. a computer is only as smart as the info you put into it. also a quick test for that is once the car stalls ho,ld your foot to he floor on the gas and crank it. if it starts then that coolant temp sensor is most likely your problem. by putting your foot to the floor like that you are putting the car in clear flood mode which cuts all the injector pulse. if the car starts that means u are doing it on residual fuel.

 

put teh stock intake on and see what happens

also take the utec off and see what CELs it throws

but the problem is the car will run too lean i think or too rich

so maybe hook up a wide band with the utec and see waht the air fuel is before and after when its cold and when its hot