Will my ECU send out the right error codes?

[supraturbo_mk3]

I have a 7MGE ECU on a 7MGTE.....I know I know, I bought it that way....Yes I plan on changing it along with the wire harness....But for now I want to check for any problems I may have so if I were to check the error codes would it give me error codes for boost leak? Or running lean or rich??

[cre]

I hope there's a good fuel controller in there... if not you may find yourself looking for a new engine sooner than you'd like.

No, for reasons beyond my comprehension the GE ECU has no functionality for diagnosing turbo related problems... There is a lean code but it simply indicates that the system is taking in way more air than it thinks it should according to the fuel maps... absolutely no good for any real diagnosis of air/fuel mixtures; What you'd need there is a wideband.

[Sonyps307]

You might get all kinds of codes flashing. Does it even run good.

[supraturbo_mk3]

Yeah it run's drives really good but I don't drive because I'm afraid it's probably running really lean, so before summer brakes I plan on installing a GTE wire harness, ECU, maft pro, and wideband sensor then have it properly tuned and go from there.

Thanx for you help guy's, I was afraid that would be the case.

[cre]

Get thine arse to a performance shop for a couple dyno runs. Do a slow one as well; This will give you a graph of your AFR (make sure their dyno printouts include that, it's uncommon but some shops don't unless you ask) at each RPM. It's only going to cover the higher loads but it'll let you know if there are any danger zones.

[Travis89Turbo]

Now this has got my wheels turning as to why someone would do this....

The GE Ecu won't have a fuel cut correct?

With this GE ecu wouldn't the BOV then be able to be vented to the atmosphere with out significant rich spot between shifts?

Of course a fuel controller would be needed to stop detonation from even the stock boost. But if the other questions above are both correct then that could be an alternative to the Lexus Afm.... and save mad tuning for the bov venting normally required on the gte ecu? And this should able to be achieved with a simple piggyback system right?

Oh and I bet if u open the glove box area you will see where the previous owner had the fuel controller hooked up!

[cre]

Originally Posted by Travis89Turbo

Now this has got my wheels turning as to why someone would do this....

Oh boy.... this opens up for a VERY long discussion... I'll try to keep this short as I don't have all the time in the world (just most of it, unfortunately).

Why? Generally because it's cheap, easier than swapping everything, works (sort of), and laziness.... oh and it's cheaper.

Originally Posted by Travis89Turbo

The GE Ecu won't have a fuel cut correct?

The term "fuel cut" doesn't actually refer to what people in the turbo world generally think... I'm not going to get into it though... just had to bitch.

No, the GE does not have such protection as there's really no way even a modded GE could take in ore air than its fuel maps allow for.

Originally Posted by Travis89Turbo

With this GE ecu wouldn't the BOV then be able to be vented to the atmosphere with out significant rich spot between shifts?

No, it'll still have the rich spots as the air was already metered. Unless the system is able to read how much air is actually in the system at the time of discharge you'll still have that over richness. It even happens in systems which people generally think are immune under extremely high boost situations (I'm referring to MAF blow through setups and S/D setups); The ECU can only react so fast and if there's 40psi of air in the plenum it won't be able to pull the signal for the extra 200cc/m of fuel fast enough.

Originally Posted by Travis89Turbo

But if the other questions above are both correct then that could be an alternative to the Lexus Afm.... and save mad tuning for the bov venting normally required on the gte ecu? And this should able to be achieved with a simple piggyback system right?

See above.... You can tune the existing GTE electronics for an atmosphere vented BOV with a good piggybck, so why on earth would you want to downgrade electronics?

Another problem with this is that the GE runs much more aggressive timing maps than you'd run on a forced induction engine (if you want it to last) so now you need to add a timing management solution... or pull 4+? from the base and kiss your low end performance goodbye (not that the GTE performs well on the bottom end, but fortunately it's not there for long).

Originally Posted by Travis89Turbo

Oh and I bet if u open the glove box area you will see where the previous owner had the fuel controller hooked up!

Oh, I doubt they bothered. As I said, you CAN run it, but it's a bad idea. Fortunately, Toyota designers are paranoid and run everything rich as hell in open loop mode. The GE tends to run at the upper limit of what's considered a safe AFR for a forced induction engine but I don't know about the maps when the airflow gets that high. Optimum safe AFR for a naturally aspirated engine is argued to be between 12.1:1 and 13.1:1; This is the max power at a safe mixture to keep temps down and prevent detonation. Optimum for the AVERAGE forced induction engine is argued to be between the high 9's and mid 11's. The GE tends to run the high 11's to low 12's.

You can run just about any 3 liter I6 on an EMS for any other 3 liter I6 as long as the fueling maps support it and the timing maps are close. I've seen 2JZ-GTE's run on 7M-GTE electronics and even stranger combinations... try a turbo charged BMW E36 running 2JZ-GTE electronics.




BUT, to put it simply: There is NO benefit to running GE electronics on a GTE.

[supraturbo_mk3]

Originally Posted by Travis89Turbo

Now this has got my wheels turning as to why someone would do this....

The GE Ecu won't have a fuel cut correct?

With this GE ecu wouldn't the BOV then be able to be vented to the atmosphere with out significant rich spot between shifts?

Of course a fuel controller would be needed to stop detonation from even the stock boost. But if the other questions above are both correct then that could be an alternative to the Lexus Afm.... and save mad tuning for the bov venting normally required on the gte ecu? And this should able to be achieved with a simple piggyback system right?

Oh and I bet if u open the glove box area you will see where the previous owner had the fuel controller hooked up!

To be honest with you when I noticed the distributor and I asked why that was on there he explained to me then it had a GE ECU and wire harness I was shocked to say the least. Then I asked why? He said he accidentally threw away the coil packs to the 7MGTE so he had to go this s route.......It was an older guy mid 40's he buy's builds and sells mainly muscle car's......The guy is really good with engines so his downfall was probably the "I can do anything syndrome" and I must say although this is not what I would have even considered doing the guy did a great job with what he had.....It's not a hack job the wires are not hanging and cut everywhere and it surprisingly runs good idles smooth. I don't drive it because I think it's a ticking time bomb but for 1500 I basically stole a turbo supra with an engine with only 34K miles......Plus I'm only the 3rd owner and he provided a folder of the car with pictures over the years and every single receipt from any repairs and basic maintenance done to the car from 1993 when he bought it to now including every oil change, brake job, and tire replacement.

[cre]

Was the car N/A or Turbo to begin with? The title will start with either JT2MA70 or JT2MA71. If it starts with JT2MA70 it was N/A to begin with and was probably a lazily done swap to begin with...If so I'd start snooping to make sure everything is where it should be for a GTE including items such as the oil cooler.

What color is the top of the fuel injectors?

[supraturbo_mk3]

Originally Posted by cre

Was the car N/A or Turbo to begin with? The title will start with either JT2MA70 or JT2MA71. If it starts with JT2MA70 it was N/A to begin with and was probably a lazily done swap to begin with...If so I'd start snooping to make sure everything is where it should be for a GTE including items such as the oil cooler.

What color is the top of the fuel injectors?

It was originally N/A.....It was definitely a lazy swap or he would have taken the time to go out and get a GTE wire harness and ECU.....I can check the injectors tomorrow but I'm sure they are GTE injectors because the engine JDM engine when ordered came complete.