Redtop Engine Misses @2000-2500 RPM....Please Help!!!

[dlucas]

I have a 95' 240sx with a S13 redtop motor installed. Lately...I have been experiencing a weird problem. When i start my car in the morning it seems to idle fine and doesn't make any noises. After about 5 minutes of warm up...I get in and press the gas and everything is fine up until 2000 rpm. Once the tach needle reaches 2000 it suddenly starts to sputter and it falls back down. If I mash the throttle....it will rev past 2000.....but if i press it nice and slow it will miss badly. Anyway....I can usually back the car out of my driveway and drive down the street but I get a severe sputter and miss when i cross the 2000-2500 rpm range. I have to mash the gas once it starts to sputter to keep the car moving.... Anyone have any ideas on the problem????

[SpeedRacer1]

ECU error codes?

[dlucas]

No error codes yet.....I am hoping to take it to a shop some point over the next week. Its really strange. On a really warm day the problem is less significant. On cold days....it seems to really miss and sputter during this rpm range. I was thinking vaccum or intercooler pipe leak....but all of that seems to be ok. The car had been running fine for the last 12 months. This BS just started happening this week.

[SpeedRacer1]

How are the plugs?

[dlucas]

Plugs look ok....they are alittle old. But no signs of fouling/carbon buildup/oil. The plug tips are the normal worn....light tan/greyish color. There isn't any black stuff on the tips.