Rhythmic power loss around 2500 RPM

[Danio]

My 1992 S13 hesitates/stumbles a tiny bit between 2000 and 3000 RPM. This happens in any gear and only while driving at a constant speed or when accelerating. Doesn't happen when decelerating. When driving at a constant speed in that RPM range, the car seems to rhythmetically lose a bit of power. Something like this: normal for about one second, slight loss of power for about one second, normal, slight loss, normal, slight loss, so on. Anyone know what I should check?

[Var]

does it have anything to do with the throttle angle? If so it could be a bad spot on your tps.

[95Blue240sx]

you know what i have the same problem in my 95. it kinda feels like the car is ok, then like it retards timing till 3k then norm again.

[twitchy]

ten four same thing here, you described it perfectly- Im going to change some plugs and wires, if not then ive been suggested its the TPS...I wonder if you can clean a TPS

[kenshinS14sks]

i've had a similar problem with my the engine dropping like 300 (NOT 3000) rpms at random speeds and revs ... from the diagnostic of the dealer, friends, and other car places...it was bad o2 sensors ... my s14 has two sensors (one right after the header and another after the cat) ... dont know how many the s13 has but check to see if the o2 sensors are clean and functioning properly.

[95Blue240sx]

the engine does not drop in rpm's at all. it just feels like a power loss from 2500-3000, but the rpms are going up like normal.

[Danio]

I didn't mean that the engine drops 2000 to 3000 RPM. I meant that the problem happens only while I'm driving at 2000 to 3000 RPM (for example, 40 MPH at 4th gear). It would feel like I suddenly let off the gas very briefly, and did that repetitively.


it kinda feels like the car is ok, then like it retards timing till 3k then norm again. You mean when you're accelerating, right? Normal from idle, then weird from about 2k to 3k, then normal? Cuz that's how it is on my car.

Is that what happens when timing is retarded?