ECU (UPDATED)

CSAlltrac

New member
For my 91 ST185 I have a BLITZ tuned ECU, it runs way to rich so I want to look into getting a different one but I dont know what the best one to go with is. USDM, CS, or JDM. I dont want to have a boost cut cuz Im curently running about 14 lbs and when the AFR are correct it feels really good. So can someone please tell me what MAP is the best, I would imagine the CS would have a pretty good MAP on it.
 

Gary ST165

New member
what sort of AFR are you getting with the Blitz up to 4000 rpm and then upto 7000 rpm?

# do you have a dyno print out etc?
# do you have an walbro 255 lph fuel pump or similar, or an adjustable fuel pressure regulator?


> maybe it has been reflashed for 540cc injectors as opposed to stock 430cc injectors.


In all fairness, all factory ecu over fuel including Carlos Sainz & RC etc . As do the aftermarket Blitz, Mines, SARD but to a lesser degree in some areas of the dyno plot etc


having talked to a few guys on GT4OC there is some consensus that out of thw stock ECU, the JDM ST185 RC is the best ecu of the bunch, when used with the matching RC AFM. However it still runs rich. ( I have tested RC and MINE's & SARD ecus on my ST185. And my butt dyno and fuel economy says the RC ecu is better suited to my driving style @ 12 psi)

Realistically a fully reprogrammable stand alone is the best way to go, but at a cost $$$
( I have Link G1 & Apexi Power FC programmable ecus on my 165 and 185RC, and i will shortly be buying a Link G4 or MoTeC M400 to replace the Power FC )




hth
 

CSAlltrac

New member
My AFRs on my AEM wideband go to 10 and thats the richest the gauge goes so i bet im hitting 9s at some rpm points. I do have a 255 as well as a FPR. I plan on going full AEM as soon as I can but the super rich conditions I have with the blitz are horrible.
 

Gary ST165

New member
the 255 fuel pump is doing you no favours with regards to your over fuelling (+40%), unless you reduce your base fuel pressure accordingly and monitor with the wideband....
>>> but i can only guess that you must have already tried that right? :shrug:
 

CSAlltrac

New member
yeah I have tried lowering my pressure but i havent switched out the fuel pump for stock. It really sucks cuz if it werent running so rich the tune on my BLITZ would be a very good one, it pulls very hard when the AFRs are in the 12-14 range. To bad it goes super rich when I give it full boost and really lay into it.
 

CSAlltrac

New member
So I possibly found a solution to my problem with MAPECU. Just wondering if any of you guys have installed this system, it looks pretty straight foward I really just need to know if the wiring diagram that mapecu.com provides for a sw20 3sgte will be acurate for my 91 st185, if so I think I can handle it. Also for those who know this system, where a good spot for the map sensor is. I would still like to know the experience some of you may have with this. Sorry for sounding real newbish, Thanks for all the help guys.
 

Simba

New member
The "extra chip" ECUs (blitz, Gforce, etc) do nothing to the fuel maps. They generally remove the speed limiter on JDM ECUs, increase the rev limiter, increase or remove fuel cut, and in some cases run more timing (similar to a JDM ECU). ALL Toyota FI ECUs run pig rich, and for good reason.

Lowering your base fuel pressure is an amazingly bad idea. Use a full standalone, or some sort of programmable piggyback that can properly control fuel independent of timing.

I use a MapECU2, works great. And yes, the MR2 3S wiring is fairly accurate. The pin locations are different across years, but so long as you tap the right wires, you're fine. Do not use the internal MAP, it's junk and running a vacuum line through the firewall is a kluge. Get an AEM or GM 5-bar and run it in the engine bay, with a dedicated pickup off the manifold.
 

MWP

New member
Simba":1zne4wag said:
Lowering your base fuel pressure is an amazingly bad idea.

Very much agreed.
You might make the top end leaner, but youll make everywhere else leaner as well. Bang.

Do not use the internal MAP, it's junk and running a vacuum line through the firewall is a kluge...

Nearly all aftermarket ECUs have internal MAP sensors.
You think it creates inaccuracies in the readings, or is it you just dont like running a vac line into the cabin?
 

CSAlltrac

New member
Im now on MAP and the car is running amazingly better, its like night and day. I am amazed at how simple the setup is and how much it opens up tuneability.
 

Simba

New member
MWP":1f6ggs18 said:
Nearly all aftermarket ECUs have internal MAP sensors.
You think it creates inaccuracies in the readings, or is it you just dont like running a vac line into the cabin?

I've seen some of them end up with what amounts to sensor lag given the amount of line that needs to exist between the manifold and internal sensor in most cases, compared with a tiny run of hose and an external map. That's beside the obvious issues of running hose into the cabin-- a boost gauge is one thing, a sensor keeping your engine from going kaboom is another.

Also, most of the internal sensors are only 3-bar.
 

MWP

New member
Simba":319j1n18 said:
I've seen some of them end up with what amounts to sensor lag given the amount of line that needs to exist between the manifold and internal sensor in most cases, compared with a tiny run of hose and an external map. That's beside the obvious issues of running hose into the cabin-- a boost gauge is one thing, a sensor keeping your engine from going kaboom is another.

Then it hasnt been setup correctly... probably the line has been kinked, or there is a restriction somewhere in the line.

Also, most of the internal sensors are only 3-bar.
[/quote]

Thats not a problem for 90% of people.
Not many run above 25psi of boost.
 

88st165

New member
CSAlltrac":31blt17n said:
Im now on MAP and the car is running amazingly better, its like night and day. I am amazed at how simple the setup is and how much it opens up tuneability.

I just finished the install of MAPECU1 of my car. Just curious as to which fuel table you started off with. Did you use the map for the mr2 with stock injectors supplied with the MAP-CALV2.3 as the base? Or did you just go get it dyno tuned? Currently im running it in learn mode to build a base map bc im curious to compare it to the base maps for the gt4 and mr2.
 

88st165

New member
MWP":28mg5dbh said:
Go get it properly dyno tuned.

No base or self-learned map will be good enough.

Yes I am aware that I should take it to the dyno and I am planning to. The point of a good base map is to reduce the physical time spent on the dyno. At $200/hr for a "professional" to tune it gets pretty pricey. Thats why Im asking CSAlltrac what he did.
 
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