Hi All, need some help!

1995 Impreza WRX JDM V1

Mods - FMIC, decat exhaust, apexi FC ECU, BOV blanked off, induction kit.

At 4000-5000rpm car has hesitation and doesn’t boost past 0.4 bar. If car is pushed hard it sometimes will struggle past and then I get fuel cut (only done this couple of times).

Feel like I’ve tested almost everything!

Tested -
No fault codes when in diagnostic mode.

MAF sensor all good, checked voltage under idle and under load.

Knock sensor - only reading a knock of 31 when driven. Sensor looks in good order

Vac lines all checked and good. Boost gauge reading negative when on idle.

Restrictor pill put into input line on boost solenoid.

Boost solenoid - removed, tested and cleaned. Clicks constantly when in diagnostic mode

Actuator - pressure tested. Cracks open at 0.4 bar and then continue to moves until fully open.

Vac lines checked they all go to correct places.

FMIC is new and all seals correct.

Fuel filter and new spark plugs put in.

Removed fuel pump, looks good but going to replace for a 255 walbro anyway to see if that solves problem.

Car had a standard ECU on it a few days ago. I changed to apexi to see if the base map would solves the issue. It didn’t. Car has not yet been mapped, just want to get this problem sorted and then get it all mapped in.

Car was sat for 5 years before I brought it. It’s always had the same issue. I’ve added FMIC, induction, blocked BOV whilst doing body work.

If anyone has any other ideas of what to test that would be very much appreciated!

 

Have the plugs and coils been replaced?
I had the exact set up years ago on the standard ecu for a number of years, I imagine that would be a safer bet than the Apexi until it's mapped.

 

I changed the spark plugs when I brought the car. They didn’t look too bad. Replaced to iridium NGK ones. I haven’t changed the coils. However there’s no fault code saying that there’s an issue with any of them? Car idles fine.

I can’t remember if I gapped the plugs. Do the NGK plugs definitely need gapping before going in?

Thanks

 

Speedometer working?

 

Yes speedo is connected and working

 

It's in limp mode I would say cause it's reverted to actuator pressure. There should really be no restrictor pill if your fitting an Apexi to be mapped. Even then its piped up completely differently. It needs put back to the original and then get your mapper to fit the parts that he wants. All the work you have done has probably resulted in. Knock sensor - only reading a knock of 31 when driven. !!!

 

The original coil packs are known for breaking down under boost so that would be my 1st part to change ( upgrade to the newer coil pack)

remove the line going to actuator and run full boost see if it still occurs

 

If it was the coil pack, wouldn’t it show up when you count the CEL when it’s in diagnostic mode?

Thanks for the help.

 

No, because 1 although its faulty its not faulty, its weak, so working as it should but under boost its not generating the voltage needed to sustain the strong spark and 2 unless it was a major misfire a faulty coil pack on its own on a 95 wrx wont throw up a CEL


Ive just re-read your initial post and if you have indeed fitted a FMIC and not altered the AFR`s or timing this again wont be helping the issue

 

I see. I’ll order some new coil packs then and see how they perform. The issue was there before I fitted the FMIC.

Thanks