I have a JDM 1991 turbo car and the previous owner installed an Apexi Power FC and it drove fine. After about 150 miles it started bogging down hesitating on throttle at 4000-4500 RPM. Idles fine, no hot start issues. The OMP was out when they put the new computer in. Anyone have any similar issues? I’d like to try to figure it out before I take it to my local rotary shop.

 

fuel filter? plugged exhaust?

 

I have not checked the fuel filter on the frame rail, the filter on the pump has quite a bit of orange rust caught in it. And the exhaust is pretty freed up. Doesn’t have any cats. At least not factory cats. The engine has 69000km.

 

Inspect condition of spark plugs?
Check afr’s via wideband to see if running lean with higher load?
check grounds?
have a datalogit to check if power fc was tuned and make sure configuration is set correctly?

 

If you can't check AFR or running fuel pressure, I'd start here. Replace the fuel filters and clean out anything in tank.