hp lag? help!!!!

[poteat45]

ok so i scored another 92 s13 dual cam last tuesday and when you floor it the car has a lag in power from 2500 rpms through 4000 rpm. this happens in every gear. and also if ur moving above say 20 mph and push in the clutch the car dies instead of idleing. the ecu self diagnostic check says that everything is normal. im pretty sure both instances are caused by the same thing.

please someone give me some ideas

much love to the 240 community,
connor

[Razi]

I'd check the fuel filter and air filter.

[seang]

I would also check the: spark plugs/wires, vacuum lines, electrical connections.

[poteat45]

replaced air filter, spark plugs, fuel pump and checked electrical conections. Could it be the intake manifold gasket letting air in? or maybe a fuel pressure regulator but i dont understand why that would cause the car not to idle while rolling above 20 mph

[seang]

I have seen a few KA24 dyno charts that show a drop in torque through that RPM range. It comes off idle pretty good, gains ground for a moment, then dips until 3-something thousand rpm where it starts to go up again. Here is one example, the site I lifted it from says it is a stock 1996 model 240sx:

[poteat45]

well that would make sense.. last night decided to clean the maf with maf sensor cleaner and it decreased that lag in power from 3k to 4k but the car still cuts off while coasting with the clutch pedal in.