ka24 cuts out?

[David s12]

okay guys, i dotn have a working tach to say when it does, but i know its not at redline, but deff at high rpms

ive had it happen at drift events, and on the drag stripp

just high rpms, in 3rd, somtimes 4th gear

mostly when i floor it, or downshift and floor it

has happened at second gear

car basically just dies. its still running, but even with the throttle down it gos WAAAAAaaaaaa and dies down the rpms for about 2 seconds.... so i roll through a turn, down the track. and wait for it to initiate again and i continue





whhyyyy

[David s12]

yea

[David s12]

yea

[Razi]

So, when you're in the high rpms and you floor it, the engine starts slowing down?

Maybe a tach will help you see what's going in more detail.

[David s12]

tachs r for b****es

lolbut, i mean it doesnt go slow, it literally DIES, it feels like the ignition is cut off... but the car doesnt die, it will just go down the revs... until it initiates again, and if i put it in neutral, it will still idle, if i shift within those 2 seconds, and use the gas, etc. it still wont work afetr that, i have to wai the full2-3 seconds no matter what gear change i do

[landygrundy]

im having the same problem, mine happens around 4500rpm, but i can just rev it and it will die at 4500 and and fire again around 2500... same while in any gear... any help would be great

[David s12]

??????????????????????????????????????????????????????????????????????????????????/f***kkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk

[diabeticon]

My KA did the same thing when i was playing in a parking lot.

230k on engine though......

[landygrundy]

check your fuel pressure, i found my fuel pressure regulator was bad, simple enough to change out but it still happens in 4th or 5th at higher rpms... thinking a bad fuel pump

[Vegascorbin]

There has been a lot of discussion on this problem in the 240 tech forum over the last few months.

Here is the short version: Car cuts out at around 4000 rpm in 3rd or 4th gear. Differant rpms in other gears. By cuts out I mean it is like the key is turned off. Let the rpm drop to about 3000 and give it gas and all is well again.

This problem appears to be unique to the SOHC motors. So far we have had one report of a fix. The person swaped out there Speed Cluster and the problem went away. A second person suffering this problem will be trying to confirm this fix later this week.

Ther is a signal that the Cluster sends to the ECU. Aperantly if this signal is faulty then you enter some type of lymp mode. You can cut the speed sensor wires at the trans and everything will work. I also know that on DOHC you cut this wire to bypass the speed governer. Like I said it is unique to the SOHC.

Most people will try to tell you it is your MAF. If your MAF is bad you (most likly) would not be able to rev past 3000.

They will also say that your 5th gear switch is bad. This could produce similar symptoms so do check that first.

Of course this assumes that you have eliminated other possable causes such as plugs gaped too wide and general tune-up type stuff.

Sorry for the long post. I have been fighting this problem for over a year and have done alot of research. Once we get a cluster we are going to try this fix also. The prior owner of the race car removed the cluster and the car has had the problem ever since we got it.

[cornuts]

hey bro my car just started doing somthings like this 2 days ago but its like u said it dosent seem to rev over 3000, it just bogs out and it starts sputtering. that can be my maf u say maybe also it idle's at 1500-1850 but thats another story i guess

[AZ89two4Tsx]

bump

I'm having the same problem. If anyone has anymore answers, please speak up.

[Vegascorbin]

We were able to fix our problem by swapping ECU. It took 3 differant ones before we found a good one.

I would clean your MAF and if that doen't work try swaping with a known good one from a friends car.

[AZ89two4Tsx]

s*** man.

I heard from FlatBlackIan on here that it could be dude to the speed limiter kicking in. My speedo doesn't work, so could it be because the ecu is getting a bad speed signal?

My speedo works sometimes. I don't think this problem has happened when it was visibly working. But yet, today is the first day I've ever noticed it.

[Vegascorbin]

Our race car does not have a speed cluster in it. There was a poster in the 240SX tech forum that was able to fix this problem by swapping his speed cluster.

there was also one poster besides me that was able to fix it by swapping ECU.

To test if it is the speed limiter try disconnecting the speed sensor for a shot while.

Good luck.

[Papo_KA24_S13]

Have U change your Fuel filter cuz mine was doing the same till I change It.

[locoluna825]

Sorry to dig this up.

my friends 89 240sx is doing the same also, its a stock manual car SOHC his HUd and cluster does not work. He has the same issue in 3rd gear car cuts out at around 4500 rpms. not sure if it does it in 4th, (were affriad to go that fast i8n his pile of crap.) people telling him its his fuel filter and other things too but i ran the codes on that car and its throwing a speed sensor cicuit code.

so judging by this thread i think we should try swapping out his cluster to a good workign one. and check the wirring on the transmission. weve also traded computers, stuck a auto one in and it went away. but we all know why it wont do that for obvious reasons.

Just posting for others sake with the same probi will reply if and when we fix this.

[zerepdivad]

If it's something with teh speed sensor circuit why don't you go ahead and jack up the car and unhook the speed sensor? Then see what happens.

[locoluna825]

i dont know wouldnt still do the same thing?

[David s12]

i swapped to a auto ecu and problem disapeered

its been mentioned like 50 times in this thread lol. auto ecu

[LambJerky]

This happened to me when driving an '82 Fiat Spider over a series of parallel train tracks. It just died but did not turn off completely, just idled low with almost no throttle response.

It ended up being the fuel pump which was not installed properly. So, that's always a possibility.