when i am driving my car, it doesnt want to go any higher than about 3k rpm. i think this is the turbo, but i am not sure, i hear that the turbos on ca18s are usually dead, so my problem being the turbo wouldnt surprise me, and i am prepared to rebuild it. however, i am confused because the car doesnt smoke, which i thought would be the case if the turbo was dead. also, it will rev higher, but it takes some hard throttle and it feels like there is something trying to hold it back from revving higher, kind of like a limiter. also, this was only my 2nd time driving the car, so i dont know what it would be like normally, so there might be nothing wrong at all, but this just seems very abnormal. i have an 89 240sx hatch with a ca18det engine. the engine has about 22k miles on it. it is currently using the stock 240sx exhaust so i can drive it to the muffler shop next week to put on the 3 inch piping to the nismo muffler:D any help is greatly appreciated, thanks - tim

If I had to guess anything I'd guess MAFs or fuel problems. There's also the chance your fuel pump is not feeding enough fuel for you to boost it. Not sure without seeing the car, but theres a few options for ya.

I agree with daunttless that it's somewhere in your fuel or electronics. I would check the ecu for codes, but I seriously don't think it's your turbo causing your motor not revving past 3k rpm.

The ecu has a "get you home mode" if one of the engine sensors goes down but that limits the revs to 2000rpm, try unplugging the CO probe and go for a run and see if its any better, also cleaning the afm/maf element might help.

Get a timing light on the engine, it maybe a defective crank angle sensor, if the car feels like its holding back then it could be that.

what happened right before it started doing this?

i really havnt driven it more than twice, because i just finished dropping the engine in. but i did have a rag over the mafs when i ran it at first, so i wouldnt suck anything into the turbo, i took it off, and i havnt reset the ecu since then, would that have anything to do with it? also, how do i check the ecu for codes? im new to the 240sx, so i dont know all that much. ive got a hks intake coming in next week, so im gonna see if that will help. it also doesnt idle, but i dont know if this would have anything to do with my problem, because i think i can just adjust it and it will fix this. details on the idle problem is that it starts fine, then drops and dies almost instantly, i have to keep it revving at about 1200 to keep it from dying. i think this just needs to be adjusted.

sounds like the timing, or other previously stated problems, also check all your vacumn lines to make sure they are all connected or block off if not in use. my motor hasnt been timed n the intake isnt even hooked up right but i got it to start an idle fine just doesnt want to rev up, i had alot of problemns when i bought it , it wasnt running anymore , i had wiring problems the MAF,O2 sensor, various ground wires were poorly wired, new plugs tighter wiring an it started right up

You ran it with a rag over the MAF and didn't reset the computer? Reset it, I seriously doubt that will completely fix it but it is sure to help a little.