Low power in KA24E

[kunsx]

Just got my "new" engine started in my 521 pick up and was a bit dissapointed since the power only was around 100hk in the dyno bench. The engine is from a truck but I have replaced the inlet manifold with one from a Nissan Prairie. There is KMS engine management system and is tuned in a dyno bench. There is a few things I think of myself,

1: To small exhaust- only 2" so get that rebuild to 2,5"

2: Myabe my O2 sensor is not working right or temp sensor- to be checked out.

3: I have the complete cylinder head of the Prairie engine- get that one ported and planed 1-2mm and replace.

Any ideas is much apreciated.

 

[datzenmike]

1/ Two inch is plenty for an unmodified engine.

 

2/ O₂ sensor is only used by the ECU during part throttle and when engine is warmed up. Full throttle I believe forces the ECU to revert back to a stored air/fuel map that is much richer for better performance and not for economy. I may not be explaining this properly but this is close. Could the TPS (throttle position sensor) not be signaling that you are at full throttle?

 

3/ If this is something else out of adjustment, a ported head will be an expensive disappointment.

[datson4life]

My ka lacked power, but after timing it (about right) new o2, and new spark plugs, it was night and day

[flatcat19]

TPS or MAF.

[kunsx]

Thanks for the answers, I am away from home at work but I will certanly check out the O2 sensor and change to new spark plugs when I get back.