Hey all, in attempt to isolate my main problem of the car just falling apart between 2.5-3.5k rpms shaking so bad, I begin to wonder about something i noticed..

With the ac on, any time i'd put it in neutral to come to a stop or something the revs would drop really low, like 400 tops and the engine would sputter and then itd catch and idle at oh i don't know, 600 or 700.

In addition to this, WITH OR WITHOUT AC ON, sometimes when I hit the gas (even just a tap) or sometimes when starting from neutral into first, even if fully warmed up and all, the revs drop dangerously low before going up..

So.. hit gas, revs go down below where it was idling, then up..

Hoping this will help isolate my major problem here, cause that sounds really weird..

 

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I am actually having a fairly similar issue with my 240SX. At idle, if I hit the gas more than 15% of the way to the floor, the rpms drop to 500rpms and will just bounce from 500-1000 in rythmic up and down occilations.

I already tried replacing the fuel pump, battery cables, distributor, wires, plugs, O2 sensor, rotor, and regrounded the battery. Still happening.

Someone recommended I change the alternator since my battery light lights up a little and is most lit at idle.

How old is your alternator?? If you live in Maryland, you are more than welcome to try out my spare H23 alternator to see if that fixes your issue.

How old are your plugs, wires, etc??

What about your O2 sensor??

These are the first few things I would check.

 

when you would drive my old roomates WRX and hit 4500 RPM it would drop to 2k and then shoot up to normal. problem was the clutch was slipping.

kinda sounds like whats going on with yall a little.