j555pre

OK. I'm at the stage when I need to decide which way to go.

My car is currently a 1991 1.6 manual with a 1.8 1994 engine fitted. I have kept the 1.8 throttle body complete with 4 wire TPS. The A/C has been removed. I have fitted the toyota COP mod. Yellow RX8 injectors.

The car has not yet run in its presnet configuration and still has the 1991 ECU fitted.

I have kept the power steering.

Any ideas which is the best route to go and reasons? I have nearly finished my MS1 build.

I do not intend to return this car to stock. Ever!

I plan to run boost control and the improved spark mod.

Thanks

WonTon

iTrader: (17)

standalone!

/thread

chicksdigmiatas

iTrader: (11)

+10000000000

JustinHoMi

The OEM handles idle better, but that's about it! AND with a little tuning you can get the MS to idle just fine

lordrigamus

iTrader: (14)

Standalone for the win!

CRAIGO

Im intrigued as to why so many shout for standalone when all you are taking on is more time spent messing around with idle values and other mundane stuff.

I'm not having a go, I just find it amusing that having control over the fan, idle and AC etc makes it so much more "win" I'd rather just get on with tuning fuel and spark and let the OEM ecu do it fine job of handling idle, the fan, AC and any other mundane task.

Unless it's ***** waving rights - In which case, I'll get me coat...

lordrigamus

iTrader: (14)

I took over the idle control primarily to compensate for having a lightweight flywheel. Allowing me to tune my idle as I see fit for better recovery and stability.

Secondly, I took control of my fans in the off chance I decide to run a cooler thermostat. I can trim my on/off temps to my liking.

I do however miss the factory A/C compensation but with the idle settings in Megasquirt it's a close second to factory.

After all that, I saw no need to keep the factory ecu just for the A/C. There's also the random issues with sharing sensor inputs. Since I no longer needed the factory ecu, I decided to remove it altogether.

I can see your point though, I suppose it's more of a "win" in my particular application. However, it did make my ***** bigger anyway.LOL

Cheerio mate

shuiend

iTrader: (24)

Buy an MS3 and go full standalone. It is what all the cool kids are doing. And by all the cool kids I mean Braineack and I.

WestfieldMX5

I totally understand your point, and and thinking of doing just the same. Let the stock ecu handle idle and let the MS do the rest (can't have the stock ecu handle the fan because that circuit is broken inside the oem ecu). Removed the egr stuff already, so the stock ecu has nothing else to do other than idle.
Anyway, I was wondering how you go about this. Do you connect only the idle valve to the stock ecu and connect the injectors to the MS?

CRAIGO

That's how it is on my parellel set-up. I have GM CLT/IAT sensors and my MS vTPS is spliced into the stock TPS signal with zero issues. Ignition and injectors are solely MS controlled and crank/cam position via a retro-fitted CAS on the exhaust cam.

gospeed81

iTrader: (51)

I lold


OP, go standalone and don't ever look back. Best day of MS tuning was when I took the car to my uncle's shop for some suspension and clutch work (borrowed lift). I was listing off some of the things I'd done, and while sitting in the car handed him the OEM ECU and proceeded to start the car. The look on his face was priceless (he always thought I was an idiot).

Anyhow, the Mazda piece is a paperweight.

j555pre

Ok I think standalone wins for me.

Thanks everyone. Since the OEM ecu was for the 1.6 and I've fitted the 1.8 I presume it wouldn't work with the IAC anyway as I've kept the 1.8 Throttle body etc. I just hope I can find my way through this maxe and out the other side.

Braineack

iTrader: (62)

And by all the kids I mean I....


LEARN TO SPEAK ENGRISH SON!

j555pre

So can I use the 4 wire TPS on my 1.8 TB with my MS1?

Is this a variable TPS?

Thanks

timk

Yes to both, with the appropriate wiring.

j555pre

Thanks, I'll have to alter the wiring as it is currently setup to use the 1.6 ECU.

Do I just run a spare 4th wire back to the MS and use the existing 3 in the standard cars loom?

Joe Perez

iTrader: (8)

Zardoz has spoken.


Seriously, though. The fourth lead on the '94-'97 TPSs is an idle switch closure, just like the 1.6 cars had. (On the NB, they finally dropped this.)

With the MS, you don't need this contact. In fact, the MS wouldn't know what to do with it. All you need are the three wires associated with the analog potentiometer section. Specifically, the green/white wire comes from the MS's Vref (+5) supply pin, the black/blue wire is ground, and the red/black wire is the variable signal that goes to the MS's TPS input.

j555pre

Thanks for clearing that up for me.

Definately stuck in my mind now.

Thanks Joe and thanks Zardoz