Alright, so Im getting a 1992 Nissan 240SX SE Fastback from my cousin for FREE. It does have a problem though, he told me at about 4000 rpm it doesnt like to climb any further in rpm, he said its potentially the air filter, like its not getting enough air to the engine, but Im thinking it could also be a fuel problem. Im not an expert though, has anyone else had any similar problems? Its an old engine now, running around 170k miles but I heard the KA can run far into the 200 range. Any help would be appreciated.

 

MAF brother. you would have to have a air box full of sand for a filter to limit RPMS.

generally 3k is a failsafe enabled by the ecu if the maf is failing or dead.

the maf could use a good cleaning with electrical spray.. if he happen to run around with a dirty filter, he may have contaminated the mafs signal

 

usually when the maf is bad or unhooked it only revs at 2500 rpm's in your case its revving at 4000 rpm's so it might be a fuel problem.

 

I would say do a complete tuneup on the car, change the fuel filter and all. Run some cleaner through the gas tank and see how she does.

 

Yeah Im thinking it could be a dirty MAF too, but Im still a little bit weary. Its not a stock intake, he has been running an Injen CAI for about 2 yrs now so thats why I though the filter may have just been dirty. But I think Im gonna clean the MAF first, if that doesnt work, buy a new one. Then go with a cheap filter from like AutoZone just to see if thats a problem. If not, then Ill just have to replace the fuel filter. But if none of those work, then I will be utterly clueless. Is there anything else it could possibly be? I should have those all done within 2 weeks.
Thanks,
tClarke

 

save up money and get a SR20DET kit 5spd or 6spd. install it in the car and then go look at the thread i posted about the 9000RPM Redtop. Its a DIY

 

yup bad maf will let you rev to about 2.5k it could be fuel, but i'd do a tune up first as already stated.

 

Alright, so I have finally been driving the car, before purchase I had only taken it on a spin or two, but it will rev fine in neutral to the rev limiter, but in the gears once you him around 4 grand it feels like all the power has fallen off, as if it were a bad clutch slipping at high rpm, but rpm will raise slowly (after 4k, it revs normally up to that point) and pick up speed just as slowly. So is there any chance it could be a bad clutch?
Before I get grilled on this next one, I just bought the car and was testing it out in an abandoned parking lot. But I attempted to do a donut but it kinda just makes a squealing sound from the mid-back of car and wont spin the tires at all. It will churp them if I dump the clutch but not a whole lot their either. So is it possible it is just a bad clutch or is there a lot more hidden problems that I havent realized yet? Thats honestly about the most thurough I can explain the problem, sorry if thats not sufficient.

 

But it feels very strong and quick up to the 3800-4000 mark, there is almost no power at all after that.

 

I took it to Pep Boys today for a free estimate, they heard the rattle coming from my valve cover and told me the fact that my timing chain was f'ing up was causing the problem. That it was retarding my timing to the point where the power band was falling off. He also quoted me between $600-$800 to get it repaired, is that reasonable?

 

if your clutch was bad you'd still be able to rev it in any gear with no problem. you would really go anywhere but it would rev. i don't buy what the guys at pep boys told you. the chain being loose shouldn't cause anything drastic like you've mentioned unless it somehow skipped a tooth but i doubt that.

i think the problem is in your transmission and maybe differential. i'd change the oil and see what that does.

 

I did the complete tune up on my car and it is running very strong now, Im guessing it was the fuel filter cuz I replaced that also. But not 5 minutes after that was fixed my power steering went out, sprang a big leak and now I have to yank the wheel real hard around corners. Kinda sucks. I just put some JB WaterWeld on the entire area around the leak hoping that will cover it before I have to get a new pump :/

 

Jb Weld Ftw!!!!!!