Touge-MR

If i were to buy a gen3 ECU and run the wire, could i replace the AFM with a map sensor??

MR2TuRbZ

you wouldnt replace it with a map sensor... both the gen2 and 3 have one... and the 3rd gen uses a different scale on the map sensor i believe...

you would need a IAT sensor to run the 3rd gen ecu i believe

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'91 Turbo Hardtop
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Motor is back in the car, a few small issues to fix ... and then i can break in my clutch (spec stage 3) and then install my new AEM EMS

texasmr2

This is a great idea! But the GenIII is also running 540's and not 440's so you would also need the injectors. Are the plugs the same on the ecu's? I would REALLY like to know if this can be done and how simple would it be.

Gregg

tofushop

Eh... I've heard this can be done, but it's expensive. It's probably cheaper to just get a VPC, which will do the same thing plus being tunable.

Touge-MR

I definatly meant AIT sensor

Pred

buy a vpc

texasmr2

I would like RickyB or atleast someone who has actually done this to chime in with their
experience and overall opinion.

sleepin-mr2

I've been looking into ditching my afm but it seems the only real soution is a stand alone ems; the gen 3 ecu+ sensors and some of the other things you need to make it work on a gen II cost like 700-900$ from what I know. For a couple more hundreds you can just go buy an ems. I want to get rid of the afm too!

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jdmr215640

I have heard of people doing it, however I am pretty sure it requires more effort than you think, You could get rid of the AFM but you would need to run an IAT ( Intake Air Temperature) sensor and the map (Manifold Absolute Pressure) sensor, and any other differences between the engines would have to been taken care of aswell IE...injectors.

texasmr2

We already have a MAP sensor, an AIT sensor is easily done.

lDeeZ lNuTz

ok so you get the gen3 ecu, all the sensors, but then you gotta re-tune the car obviously. why not just get that all done at once with an ems and have absolute control of the engine?

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texasmr2

Whats to be retuned? The ECU does all that.

GenIIIMrDuece

woulnt the swap be easier to do if you just got a gen3 harness and put in on a gen2 motor or doesnt that work?

jdmr215640

A gen II uses an AFM not a MAP sensor, thats why the w. the nemesis you have to disable your cold start injector by using a map sensor in its place if we had one I am sure that it would just utilize that. AFAIK only Gen III engines come w/ map sensors stock. The AIT sensor is part of the AFM. so I am pretty sure to disable it you would at the very least need a MAP sensor and a IAT sensor.

Justin311

Do a little more research...I don't mean to pick on you, but I've seen a few posts by you today giving advice on subjects that you really don't seem to fully understand. Listen to DeezNutz on this one. EMS is the only way to go.

Mistertwo94t

The Gen 2 does come w/ a MAP sensor, a different one w/ a partially different function though. You replace the cold start injector w/ a manifold air temp sensor, not a MAP sensor.

I've thought about doing this and even bought most of the parts before changing my mind. From what I've heard from people that have done this, you need the sensors, ECU, and injectors. You will also need to rewire a few things since the plugs aren't compatible. I've also heard from at least one person that you need the ignitor off of the Gen 3. One thing that has me stumped is how many intake temp sensors you need. The Gen 3's have two stock but everyone always seems to just mention one.

As long as you are using the Gen 3 MAP sensor and injectors, I don't see why any tuning would be necessary.

There are a few things about the Gen 3 ECU you should also consider. There is a speed and boost cut limiter on the ECU that aren't as easily bypassed like on the Gen 3. You obviously can't just unplug the MAP sensor and any sort of boost cut eliminator box will just screw w/ the MAP sensor signal which I have seen cause very bad things. I planned on sending my ECU out to ATS to have both removed.

IMO, if you aren't really aiming for any serious horsepower and just want a safe way to run 550's, the Gen 3 ECU swap is definitely a viable option. I planned on running the Gen 3 ECU along w/ my CT20B and didn't plan on taking it any further so it fit my needs and plans at the time perfectly.

mrlaw

Did somebody say VPC??
Lawrence

rascaca

Totally false, EMS is not the only way to go.

you need 540cc, gen3 MAP, MAT, IAT and Igniter with ECU and some reworked wiring. and it doesn't need to be re-tuned at all.

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jdmr215640

I agree w/ rasaca you EMS isn't the only way to go, If you had a nice hook up on a Gen III setup w. all of the needed parts. I went through the BGB and I haven't found any MAP sensor on the GEN II engine. Could someone tell me where it is or find it in the online BGB, I had to put on my engine harness and I don't remember connecting a MAP sensor.

Justin311

Oh, OK, thanks for the info

So I see you have a GenIII clip for sale. Since I can buy a complete plug and play SDR EMS for $1000, will you sell me the 540cc, gen3 MAP, MAT, IAT and Igniter, complete wiring harness and ECU for $200?

Becuase then I have to send it off to ATS and spend $750 to get the board modified so that I can even boost above 12 psi where the fuel and timing maps fall off, 16 psi where the fuel cut is likley located, and oh about 120 mph where the speed cut is located. And THEN and only THEN will I even be at the starting point of where the PLUG AND PLAY SDR starts me at. And yes you can get a pre-tuned map for the bone stock 3SGTE that will run it just as well as the GenIII would, without any tuning.

Togue_MR: Of course its all personal preference, but I would ask any of these folks who are saying its a good idea if they've actually redone a genII to run on GenIII equipment (seeing how they don't even have a clue where the MAP sensor is ), and if they had to do it again or spend 1000 on an EMS, which would they do.

As well as rebuilding and rewiring quite a few GenIIs, I have used a stock ECU, an SDR and two different pre-tuned Japanese ECUs in my car, and I'm just giving you advice from somebody who's been there.

This debate is just silly, so I will refrain from posting anymroe, you knwo my stance.

Smaay

its the boost pressure sensor right next to the cruise control...it actually sits right between the intake manifold and the diagnostic plug...

KBlake

Yeah, but what's the point? It would be easier, and possibly cheaper to get a 550cc rom tune from ATS. (coming soon)

Either way, the Gen 3 stuff is really only an "upgrade" if you already have it, or can get it cheap/free. It's certainly not an upgrade path I'd recommend to anyone.

Justin311

Good point, but I think Touge's goal was to get rid of the AFM, in which case the VPC is only $500 away....once again not what I'd recommend but a viable option, much better than a silly GenIII control system conversion.

jdmr215640

If the boost pressure sensor is the MAP sensor that you all are talking about, that has no bearing on anything, Most people just disconnect theirs anyways.

Mistertwo94t

I don't see why this would be necessary considering how many people have run above 12psi on stock Gen 3 ECU's w/o any issues.

Justin311

I've also seen a guy push a stock CT26 to 25psi + w/o any apparent issues. Just because you can't physically "see" the issues doesn't mean they don't exist. Food for thought....

JDMsw20

that statement only pertains to gen2 since your ecu relies on the afm to add proper a/f mixture. People disconnect thier boost pressure sensor along with their tvis to trick the ecu into not reading boost, thus no preset factory fuel cut/boost limit.

the gen3 has to rely on the map sensor and ait to make proper fuel mixture since the afm is elimanated

KBlake

It's not just the gen 3 ECU that enables the 12 second pass. The CT20b and larger intake cam, along with lower CR, better intake manifold, and higher boost all have a lot more to do with those 12 second Gen 3 passes than the fact that it uses speed/density to measure airflow.

There is absolutely no reason to get rid of the AFM until above 300RWHP, in which case you should be shopping for an EMS, since even the Gen 3 stuff was never meant to support 300+ RWHP.

Ken

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rascaca

I wasn't saying it's the best choice but yes it was doable and will work without any problems.