turbo ECCS question

[VinhZXT]

I just read the manual and it says that the injector pulse is based on RPM and speed sensor and other stuffs which you already know. Does the ECU really take RPM and speed sensor factors into the the equation to calculate the injector pulse? Or is it just using that for the cruise controller? The ECU does have connections for both of these items FYI..

[Cody 82 ZXT]

I always thought it was based on RPM, load, and air flow

[Guest bastaad525]

I thought it was RPM, air flow (as measured by the flapper door in the AFM) air temperature (as measured by a temp sensor inside the AFM), and coolant/head temperature? Well and of course don't forget the O2 sensor under cruise.

 

As far as I know it doesn't take any kind of measurement of vehicle speed into account, I don't run any kind of speed sensor on my setup. At least not that I know of!

[VinhZXT]

525,

I have 2 280ZXTs and they don't drive the same. My 81 280ZXT drives real good and the 5 speeds 79 converted turbo doesn't feel the same. Also I did a search and found your old post about how long does the car goes into close loop and my 81 does kicks into open loop and my 79 never. If the ECU doesn't use the speed sensor and the RPM then why these 2 sensor got feed back to the ECU?

[Guest bastaad525]

well first let me ask you, where exactly does the speed sensor go? I didn't wire my turbo swap myself, but since having it (almost two years now) have extensively tracked most of the wiring, learning it and figuring it out, at least, seeing what all different components were used and such.

 

I don't have any speed sensor, as far as I've found. To be honest, I don't know what it would look like, or where to find it, so I may be wrong. I would assume it would be attached to the trans or the differential? Or does it read signal from the speedometer? There is nothing connected to my diff, and the only two things I see connected to my trans are the mechanical speedo cable and the reverse light switch.

 

If you're '79 is never switching into warmed-up mode, my first and obvious guess is you're having a problem with your head temp sensor. it's either bad or there is a bug in the wiring going to it. Another possible culprit is the TPS, either being bad or improperly adjusted.

 

And I have no idea why the ECU has connections for a speed sensor.

[Cody 82 ZXT]

The only speed sensor I ever heard of is for the cruise control. I always was told it was in the speedo cluster. I never really botherd to look for it or identify it.

[mario_82_ZXT]

Yea, the original speed sensor in a 280zx was used for activating the cruise control only above 35 mph, and for knowing when the car was moving to warn you about the parking brake, door ajar, etc.

 

I believe the stock ECU uses air flow, air temp, coolant temp, and RPM. I belive that it has 3 predefined values, off idle, cruise with minor variation through the O2 sensor, and WOT.

 

The ECU uses the TPS to know when the TB is closed, and when it is opened to add off-idle enrichment. It goes into WOT mode under high load and anything above 3500 rpms.

 

The Turbo auto ECU goes in WOT by seeing high load AND the kick down switch (which is why some people who use the auto ECU in a 5 speed swap go lean under WOT if they don't leave this connected).

 

Mario