Running Lean

[teng]

Hmmm. Went for a dyno test and my car only got 156.3hp at the wheels. Never seen a graph like this before. Fully stock engine except for a FMIC. The mechanic said that my engine is running LEAN and that there is more air than fuel. He suggested that i change the fuel pump. My current fuel pump is working and spraying lots of fuel when ignition is switched "ON". I wanted to be sure that's it's the fuel pump as that costs like over $400 new here. So any suggestions?

And one more thing, can someone tell me how to read this dyno chart. I'm lost but i do know that the line shouldn't go back to the vertical one.

Edited November 1, 2008 by teng

[teng]

Thanks to information contributed by some of the SAU members through PM and the information i got from the SAU forums, i got the lean and boost problem sorted out. Bought a NISMO 4.1L Fuel Pump to fix the Running Lean problem and a HKS Adjustable Actuator to fix the low boost problem. The Actuator is set at 0.6bar at the moment. I also bought the Adjustable Fuel pressure regulator but didn't get to use it.

Dyno results;

204.2hp @ the wheels

250.7hp @ the flywheel

Not bad considering it still has stock internals, stock turbo & stock injectors.

The stock turbo holds boost well at 0.6bar and can hear it spooling at around 2000rpm.

The one thing i do notice is that my fuel economy has risen. Before the problem was fixed, i can only get 300km. Now i can get over 400km to a tank which is a very good improvement.

Edited December 27, 2008 by teng

[MATT_R33]

where did you buy the Fuel pump and how much?? i think i need one after reading that

[teng]

check www.perfectrun.com.au . I get almost all my stuffs from there.

Edited December 30, 2008 by teng