Removing speed limiter on 93 KA24DET

Post by **babowc** » Wed Sep 28, 2005 6:23 pm

SHIFT_Lock wrote:Or just get a auto ka24de ecu. Plug it in. And you get more MPG.

can anyone verify?is there any harness alteration required?

Post by **dft24ds** » Wed Sep 28, 2005 6:53 pm

when I did my auto to 5spd swap I swapped the auto ECU for the manual ECU and it plugged right up no problem.

Post by **K240** » Wed Sep 28, 2005 8:09 pm

Yep, there is no difference in the harness, its a direct replacement!!!

Post by **babowc** » Thu Sep 29, 2005 11:25 am

i see..hmm, but i always thought automatic cars used more gas than manual?

i dont see how it can be any different >_<, but im gonna go pick up an ecu from the junkyard or something.. see how it works outi barely get 250 to a tank..

Post by **K240** » Thu Sep 29, 2005 11:39 pm

the way the tranny is set up, and gearing, 5speeds get better gas mileage, but the actual ECU's fuel map, gets better gas mileage...correct me if im wrong

Post by **babowc** » Fri Sep 30, 2005 3:49 am

ooohokie i guess ill be changing to the auto.. never knew 240sxs got this kind of.. not-so-great gas mileage

Post by **mr2lickit** » Sun Oct 02, 2005 10:27 am

So does the auto ecu make better gas milage (I heard it makes the car run rich)? I also did a 5 speed swap but I'm currently using the auto ecu and auto wiring harness. I heard that you need the manual wiring harness b/c it has an extra plug that goes somewhere?!?! I was going to purchase both harness and ecu for the manual, but if not needed I wont. Also will that effect later tuning the car if its an auto ecu. Sooooo off topic but Needed info hehe.

Post by **Florida240sx** » Sun Oct 02, 2005 10:38 am

No need for the M/T harness and ecu to drive fine. However that is a question, I have longed to ask about tuning later on.Whether it is affected.

Post by **phuphyter** » Sun Oct 09, 2005 8:18 pm

Quick (maybe dumb) question. Does the auto ecu adversely affect engine performance in any way since it gets better mileage?

Post by **Mustangs_Suck** » Mon Oct 10, 2005 11:10 am

I'm currently running the auto ECU on my 5spd swapped KA-T.

I have no speed governor, and I can go to redline in each gear.

So maybe instead of just cutting all these wires on the manual ECU, you can just get an auto ECU and have fun

The DOHC speedo goes up to, what 120?? I've had the needle go half way between the 120, and back to 0 again So obviously I have no fuel cut off anymore..

the mechanic I had said he found something that caused the ECU not to communicate well, and he just fixed it..so maybe that was it, but if not - from my experience with it, swapping to the auto ECU will eliminate all rev limiters and speed governors.

Post by **Mustangs_Suck** » Mon Oct 10, 2005 11:18 am

babowc wrote:ooohokie i guess ill be changing to the auto.. never knew 240sxs got this kind of.. not-so-great gas mileage

clean out your motor with sea-foam if you can find it. also get new spark plugs, spark plug wires, and distributor cap/rotor - those will help greatly if they haven't been changed in awhile, or at all.

As for the sea-foam. Buy one can and do as follows:Put 1/3 bottle of sea foam in the crankcase oil1/3 in the gas tankand 1/3 in the vacuum (you can use the metal tube that sticks out from the left side of the ECCS)

When you put it in the oil, let it run at idle for around 15 min. and then change your oil.

You will feel a big noticeable difference in how well the car runs, and more MPG I assume as well, since it'll clean out your gas lines and injectors when it squirts through them from mixing it with your gas.

Post by **phuphyter** » Mon Oct 10, 2005 4:06 pm

Cool. Now all I got to do is swap the ecus from my '94 altima and '91 240! My parents will never know... muahaha

Post by **Florida240sx** » Wed Oct 12, 2005 1:45 pm

I only ran my car at idle for 10minutes....178k miles...that's just me though

Post by **locolou** » Wed Oct 12, 2005 2:00 pm

Honestly the easiest way to disable the speed governer/rev limiter is to cut the correct wires from the ECU. At first I wired in 2 switches in case something stopped working, but I've had no problems since doing it so I removed the switches. All you do is snip ECU wires 32 (yellow/green) and 33 (yellow/red) and your all set. If you have cruise control, you will probably lose that, since I have a base model, I wouldn't know.

Post by **side waz** » Wed Oct 12, 2005 5:00 pm

locolou wrote:Honestly the easiest way to disable the speed governer/rev limiter is to cut the correct wires from the ECU. At first I wired in 2 switches in case something stopped working, but I've had no problems since doing it so I removed the switches. All you do is snip ECU wires 32 (yellow/green) and 33 (yellow/red) and your all set. If you have cruise control, you will probably lose that, since I have a base model, I wouldn't know.

So your saying you cut the 5th Gear Switch wire (ecu #33) and you have NO rev limiter in 4th and 5th gear's?

According to the pin out diagram, 4th gear is #42 and 5th is #33. Now would'nt you have to cut BOTH wires in order to fully remove the rev limiter from those gears?

Post by **streetracer** » Tue Oct 18, 2005 7:12 pm

I know on my 1993 240sx se hatch i have cut all of those wires.(32,33,42)I still hit the rev limiter at 5000 rpm's and it sucks. i am going to disconect the two sensors from the trans and see what happens since i have nothing to loose except a rev limiter at this time.I have notice that on the 93 hatch the # 42 is white and #33 is black i am not sure that it is the same with every one else or i might have did some thing wrong on the wires but when i read what some one else puts in on the forum i do that and the car don't wan't to start untile i hook up the wires back up. And one thing i notice is that 32 is right above 33 and 42 sits right next to 33 on the left side of 33.

Post by **streetracer** » Wed Oct 19, 2005 1:42 pm

I have un hooked all the sensors in my 93 hatch and it worked no speed limiter any more. Had to jack up car and climb under the front the the car just to get to the 4 sensor that are on the passenager side of the car.The only reason is that i had to use two hands to unhook two of the seansors have little clips on the side of the sensor that have to lift up just to get the little sensor to move. They are not that easy to pull apart so i recomend using two hands instead of one hand.

Post by **Biggamehit** » Wed Nov 09, 2005 12:00 pm

just take 10 min and run a simple on and off switch. mine works fine no redlining.

pics below buddiesmy wires run through the hole in the trans tunnel through the shift boot and then under the dash and to my switch

Post by **Biggamehit** » Wed Nov 09, 2005 12:01 pm

delete sorry

Post by **Chezedik** » Thu Nov 10, 2005 12:56 pm

How does this ECU swap affect readings on the speedo?

Post by **Guardians91240SX** » Wed Dec 14, 2005 6:53 am

But what about the fuel pump cut out ? how is that eliminated ?

Post by **ale89se** » Sat Jan 28, 2006 2:46 am

so when you cut the wire i understand that all the guages work fine, but will i get the check engine light on all the time after that?

Post by **rsmithdrift** » Fri Feb 03, 2006 9:30 pm

bump.

I want to know about this check engine light also. I don't want it on all the time........though I don't see why cutting the speedo wire from the ecu would make it come on, but the 4th and 5th gear thing I would think would freak it out or make the rpm gauge not work. I want my rpm gauge to work in 4th and 5th and not have my engine light on.

Also I have cruise control and use it alot (only way I can keep it under 80 on the highway lol) and I would like it to still work.

Post by **Florida240sx** » Sat Feb 04, 2006 4:13 am

I cut #32 and it removed it for me.Although for some reason I think I hit it in 5th but that was close to 140mph.(I was turboed) Could of either been road(rained 4hrs before and tires may of been slipping or could of been MAFS maxed out. But I sniped the yellow green and my cruise control still works Nice to be cruising along and when you go up a hill you hear your turbo spol automatically.

Post by **rsmithdrift** » Sat Feb 04, 2006 8:28 am

Ok, cool thanks, good to know.

What about that engine light though. Sorry for being a pest about it, but I don't want it on.

edit: Ok, forget the engine light part. I just did it and the engine light does not come one, but there are two yellow/green wires and I cut one and I have no speed gov, but my cruise don't work. Did I cut the wrong one?? I'm assuming this is the same wire, maybe one affects cruise and the other don't??

NVM. I was right, I cut the wrong yellow/green wire. I crimped it back together and cut the other one and viola!! Cruise control at 130mph lol. J/k, I wouldn't dare use it above 100.
Modified by rsmithdrift at 3:38 PM 2/4/2006

Post by **Florida240sx** » Sat Feb 04, 2006 3:29 pm

What you mean?My cruise only lets me go to 95mph. have you been able to set it over that?

Post by **Jookmasta** » Sun Feb 05, 2006 7:59 am

i know its 92mph from my digital speedo gauge that the cruise control maxes out........

Post by **rsmithdrift** » Sun Feb 05, 2006 1:21 pm

I said I was joking geeze. I've never set it above 80. I was just saying with that comment that I wouldn't want my cruise on at over 100.

Post by **Florida240sx** » Sat Mar 25, 2006 7:21 pm

Got to unplug the sensors.MY car cuts off at 5600ish rpms in 5th. Made my car stall out......not very fun at all at those speeds....was a backroad in between counties before I get flamed.

Post by **ka24boos13t** » Sun Mar 26, 2006 4:44 pm

S13FX wrote:Just a quick note it's the same wire for the SOHC too

Are you sure? I snipped the yellow with green striped wire 8th from the right and it cuts out in 3rd under hard exceleration. Is this pin 32? (I dont have the manual so I have no idea) Everyone in this post has said that its the yellow with green stripe and in another post someone said that its the 8th over from the right (I figured that it was the right wire since they both coincided.)
Modified by ka24boos13t at 4:15 AM 3/27/2006

Removing speed limiter on 93 KA24DET

Re: (SHIFT_Lock)

Re: (babowc)

Re: (babowc)

Re: (phuphyter)

Re: (babowc)

Re: (Mustangs_Suck)

Re: (locolou)

Re: (side waz)

Re: (streetracer)

Re: (streetracer)

Re: (streetracer)

Re: (S13FX)

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