Problems Need Urgent Help Please...

[wajouba]

Ok, my problem is that I'm having strange rev limits... in my stock 200sx S13 as for example my car cuts off at 6900 or 7100 on 3rd gear, then goes on to cut on 4th gear at 6000 rpms, and it also cuts off at 5600 on 5th gear... but the funny part is when I let go of the throttle right after it cuts off and WOT again it passes the cut off by around 500 rpms then cuts off again...

Btw, this problem started happening after changing my engine and ECU, so I thought it could be the JDM ecu, so I went on and unplugged the Yellow Green wire on the 8th pin. Went for a try, it also did the cut offs, then came back and unplugged 2 sensors which I'm not really sure are the 4th and 5th gear sensors...

From the first time I got the car, the Speedo never worked, only RPMS, and while I'm under the car, I saw that theres a third sensor which was unplugged and put beside the transmission comming from above the transmission...

Any help, or pictures of the sensors, or even something similar to this would really benefit us!

thanks alot!!!

[ca18detgabby]

is this auto? what do you mean it "stops?"

[r34 gtr]

Sounds like a speed cut, are you sure you have the correct wire? Anyone have a HKS SLD you can borrow or something? Any way of dropping in a tuned eprom chip?

[wajouba]

im sure of the wire we unplugged from the ECU, its the Yellow with green stripe, and it is also the 8th pin from the right side... but the thing is, that the problem was before we even did anything to the car... We actually went with unplugging the Wire and the sensors (which turned out to be the reverse light, and Neutral sensor lol) because of this problem. so what I did till now is only unplugging the Wire, the Sensors are wrong... where are the 4th and 5th sensors locating?! Cause I simply can't find them on the manual...

[iliketocrash]

i don't know if this applies to these motors but i know on dsm's they have fuel cut, which sounds exactly like what you're describing. It can be caused be a couple different things. #1 reason being if you turn the boost up too high on an all stock setup. Otherwise you could possibly have a bad sensor somewhere along the way.

[r34 gtr]

Do you have access to an auto transmission ecu you could try? I understand those don't have the fuel cut. It definitely sounds like that is whats happening. Strange though that it still does it after youve done all that.

[wajouba]

My engine is all stock as u said, but I never tampered with the Boost, never tried to increase it at all... and how can I know which sensor is bad? what sensors could be causing this?

btw, just to add to the info I gave u guys, when I press WOT, and the cut happens if I remain flooring it the RPM goes back to around 1500 rpm then accelarates again suddenly back to the same RPM cut...

Can you guys help me in locating the sensors for the 4th and 5th gear on the transmission, cause I unplugged the wrong ones as I've said b4... (rear light, and neutral sensor) so where can I find the 4th and 5th gear sensors?

Thanks

[wajouba]

umm i don't know about the auto ECU, does it actually work with a Manual transmission car? doesn't it need retunning or anything like that? or does it work normally..? and by the way the engine was taken out of an Auto car, and then replaced with the manual that was already on our car. Then for some weird reason that I don't know really the ECU fried up... (literarly burnt from inside, maybe from switching the TPS with some other sensor don't remember) so we went back to the place we bought the engine from and got another ECU...

so what Im trying to say here, is could the reason be that the new ECU I bought is actually an Auto transmission ECU?!

[wajouba]

Okay, bad news, I think, cause I've just checked my ECU's serial number and it turned out to be an Auto ECU, so again could this be the problem?!

Thanks!

[mbmbmb23]

Are the gear shifts on an auto controlled by the ECU? Maybe the ECU is throwing a "kickdown" signal to shift gears and that signal is on a wire that shouldnt be plugged in...and is instead shorting something else out. Find a pinout for the CA auto and manual ecus and we'll go from there.

-m

[wajouba]

Yes this is what I was actually thinking, so can someone shed some light on wether the ECU controls shifts?!

[NissanTouge87]

i know this is alittle late, but i was running an auto ECU on my CA, without any problems.

The auto trans is controlled by an auto trans computer, it has little to do with the engine computer.

As for the sensors, CA trannys dont use 4th or 5th gear sensors like the KA transmission does.

What psi of boost are you hitting when these cuts come in?..is it 7-8 or 11-12?

[wajouba]

Okay I don't know how all of u are using ur Auto Ecu's on ur Manual SX, but now that we've tried a Manual ECU we had no limiter what so ever... anyhow I have another question... whats the difference between the RS13 with a MED D007 C ecu, with 27310 39F00 vs the other ones... is this one with CAT? and what kind of Octane does it require? If we don't have the Cat sensor wirring in our harness because the car came without a CAT, can we rewire it?

Any info about this ECU is helpfull...

Thanks everyone...