Blktop ECU# diff/ Run Trouble codes??

[MrFairlady]

Well the BlacktopSR in my Coupe will not rev past 4k rpms in 4th & 5th gear 1-3rd are fine it seems - has an E6 ECU that dosen't seem to have the diag light on it (like my 63) to run codes and I belive its not wired up to Flash the MIL either,like probably from the factory on the 180sx should do?.

Can I swap my Redtop 63 ECU and try that on a Blktop??Run codes from that?
or Consult the only way to Diag Issue @ this point?

*Basically*?
running a diff ECU - will it perform any diff enough to just see if the ECU is the issue (swapping Red ECU to a Blktop)?
All it (E6+/Blktop ECu's) does is allow for a reading on a "Fat" o2 sensor correct?ALl other readings should be the same considering its basically the same engine?

[SoSideways]

Hmm... I think you have an automatic ECU, so maybe that's the cause?

I have the E5 for my black top, which is the standard manual trannied black top's ECU.

63 sounds like an automatic red top ECU, as I think the manual version is the 62...

Anyway, there shouldn't be any problems running the 63 ECU on your black top to get diagnostic codes.

If it's anything like the difference between the 62 and E5 ECUs, then the only differences would be the O2 sensor wires need to be switched, and you'll need to run the skinny O2 sensor for the 62/63 ECU instead of the fat one for the E5/E6.

Also, if you don't have the LED on the ECU itself, you could always use the CEL on the gauge cluster to check for codes (you should have wired it up if you hadn't done that).

[Quigs]

I tried swapping my blacktop ECU for a redtop for the same reason: to read the codes. However, when I wired up the redtop ECU, the motor wouldn't start. I guess it's always worth another shot though. I never looked any further into it.

[SoSideways]

I tried swapping my blacktop ECU for a redtop for the same reason: to read the codes. However, when I wired up the redtop ECU, the motor wouldn't start. I guess it's always worth another shot though. I never looked any further into it.

Which black top ECU did you have before?

[Quigs]

I have an E5 ECU.

[MrFairlady]

Well I bought the car this way (already swapped) and already plan on Doing everything Over.
My Redtop ECU (on my Daily) is an Auto and is supposedly better (no speed cut,etc) and this Coupe Was prev an AUTO SR BlkTop w/ Auto Trans *(rare) -
converted to a 5speed later.

oh well..I'll just pull the motor and re-do the STuff I'd already planned on.Use the Lower KA Harness that I have coming instead of the Hack Job it has now (Auto SR Lower harness in conjunction w/ the 5speed Swap (ugggggh Ghetto)

[SoSideways]

Yeah see, mixing and matching like that, who knows what happened down there. Wires could have been mismatched and wired up the wrong way... no way to really tell unless you took it apart and re-did everything.

The auto ECU will work on the manual cars, but I just don't really trust it, seeing as it probably will back off the timing or something up top, when it THINKS the car has to up shift to a higher gear.

Don't quote me on that one, as I have no idea if that's what happens, but I would think that the ECU itself was programmed to a certain degree to suit the automatic transmission's characteristics so that it could work in conjunction with the auto trans computer, which controls the shifting.

If the auto trans computer controls the shifting AND sends a signal to the ECU telling it that it's about to up shift, and to delay the timing a split second while it does so, then that's a whole different story.

[MrFairlady]

Yeah see, mixing and matching like that, who knows what happened down there. Wires could have been mismatched and wired up the wrong way... no way to really tell unless you took it apart and re-did everything.

The auto ECU will work on the manual cars, but I just don't really trust it, seeing as it probably will back off the timing or something up top, when it THINKS the car has to up shift to a higher gear.

Don't quote me on that one, as I have no idea if that's what happens, but I would think that the ECU itself was programmed to a certain degree to suit the automatic transmission's characteristics so that it could work in conjunction with the auto trans computer, which controls the shifting.

If the auto trans computer controls the shifting AND sends a signal to the ECU telling it that it's about to up shift, and to delay the timing a split second while it does so, then that's a whole different story.


Dude....that makes ALot of Sence what your saying.I'd have to agree now that you say that.My Redtop SR w/ Auto ECU seemed to have Timing issues and now thats Pretty much all fixed (CAS Was cracked) but still quirky when very 1st Cranked up.

I have a OEM Lower KA Harness on the way and plan to Re-wire the Trans stuff once I take out & put the motor back in.
I'l try to find a Manual E5 ECU I guess now too.

REP for you sir (if it was still there:love:)