help...rpm doesnt go higher then 5000:S

SON240sx Automotive
1

hi…im new to this group and ive recently bought a 240sx .1990…
ive been having a weird problem which im not sure of…
maybe someone here can help me out a bit…
well my car doesnt go over 5000rpm :confused:

like after 5000 rpm it would choke…
can anyone hint me atleast…to what it could be…

2

hmmmm, insane rev limiter?

3

gas filter
or Mass air flow sensor thingy

4

nahh, its prolly too retarded, the timing that is.

5

Well. More information about your car would help a LOT!

You know, like a brief history perhaps.

1st post should have been in new users section introducing yourself.
Oh well.

6

ECU’s in failsafe mode, iirc, reset the ECU and diagnose.

7

how does your ECU got to failsafe mode lmao i didn’t even know they could do that… wouldn’t it be cheaper to grab another used ECU ?.
and when a car has retarded timing doesn’t it sound different like more harsh?like a rally car.

8

lol sorryy thats true i shouldve introduced myself in the new users section…

well yeah its a 1990…240sx…s13…
well how would i reset the ecu?
leaving the battery out for 15 or 20 mins?
yeah the car does sound retarded at times…like…a rally car…
lol actually more like a bus…
could it be a sensor?

9

KA24E. No swap? All stock?

10

all stockk…yupss

11

I have a ka24e ECu you can try and see if it fixes your problem. I also got the maf and a lot of parts. If you want let me know through a pm.

12

:frowning: ahh this is such a pain…
is there any good mechanic…who would know about this kinda problem?

13

These guys have given you reasonable advice bro,Mass air flow=not getting enough air or getting to much,a lean air fuel will cause it to "rev limit"If you have an air leak between your mass air flow and your throttle body you’ll get a lean condition.
Or try the PCM thing as well, roast could be right too!
Trial and error this is how you learn,sometime it’s easier than others

14

Disconnect the battery for 10 minutes. Re-connect.

Everything will reset.

See what happens.

15

well soo i did the reseting of the ecu…but it didnt make a diffrence
and the air flow there was no leak or anything :s
i was researching on google…and i came accross a couple of things that i wasnt sure of…
some people were talking about the 5th gear sensor…
i couldnt find where its located…

then there was another one who said…the fire wall groud…but i also dont know where that is located either…

his happens in every gear its almost like thats its rev limit when i know they can go way more then just 5,000 rpm.

16

eh check the timing…possibly maf …vaccum lines aswell culd do it if 240sxs of that year had vaccum lines new guy here just listing what i think it could be

17

Did you download and FSM’s (Factory Service Manual’s) for the vehicle?

Failsafe mode, if supported oh the SOHC ECU is when a sensor is reading out of range. I experienced it with my DOHC after my 5spd swap…

I’m moving this to technical…

18

had a SOHC,

  1. firewall Ground is at the back of the engine usually near the center slightly below the “Lip” on the firewall.
  2. I had and still may have a SOHC ecu that was in PERFECT working order when i pulled it, IF i still have it your welcome to it, and i beleave i still have a SOHC MAF you could barrow to see if that fixes the issue.
  3. If the ECU is in fail safe all of the above would be relitivly useless untill you diagnose this, which would point you in the right direction.
    4)The Stock intake pipe is plastic, and has a flexable bend near the throttle boddy on the passenger side of the car, it is VERY common for the inside of the acordian bend to crack, you may not notice it but it can cause masive issues (speaking from experiance here)
  4. also near the throttle body i beleave? there is a large vacume line (slightly larger then the average thumb) this also has a tendency to crack or harden and not seal correcty causing a leak.
  5. If timming is your issue a timming light will tell you real quick. Or having someone check the timming for you is your best route. If you like to live dangiously you could eye ball it and mess around but ur more then likely gona end up with a car tha wont run in that case…

Basicly a list of what everyone above has said. Take it or leave it…

19

what is it doing at 5000rpm?
feel like fuel or air cutting?
are pinging sound from the exhaust manifold?
running lean?
check the ecu for codes

20

my auto dohc did that to i just turned the car off then on four or five times then on and let it sit while runnign and went fine from then it happens in the winter when you rev the shit outta it to get outta the snow then once free its very very very sloooow