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Here's the scenario: I have stock 5mge injectors, but now have a 6mge motor. I currently pass smog with flying colors. Is it possible to upgrade the injectors to the 210cc (I think that's what everyone's reccommending) without violating any smog regulations while utilizing the stock ECU?

When EL Prototypes gets done with my doner ECU...well that will be my "offroad use only" set up :wink: ....but it would be a real pain in the ass if I had to switch out injectors along with my "offroad" set up. Anyone know?
 

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My 6m-gte with 210 injectors passed smog. ASM test.

Phil D.
 

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I barely passed smog in N.Calif two years ago with my lightly modded and rebuilt 5mge with 210cc injectors. New cat, tuneup, wires, I was working that AFM like crazy trying to pass. You should be able to pass too.

Heh, did EL Prototypes say they definitely could modify your ECU ? They had my '84 ECU for about a month and finally gave up. I always wanted a modded ECU. Let us all know if they come thru.

Don L.
 

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Don L. said:
I was working that AFM like crazy trying to pass. You should be able to pass too.

Heh, did EL Prototypes say they definitely could modify your ECU ? They had my '84 ECU for about a month and finally gave up. I always wanted a modded ECU. Let us all know if they come thru.

Don L.
Don,

EL Prototypes told me to get the latest model ECU possible-from (85-86) that came out of the 5mge powered supra. He said that the earlier model's ECU were impossible to work on. I haven't dropped it off to them yet because I need to wait and see how the funds are after the latest visit to the shop :? I'll let you know what happens.

Question: When you messed around with the AFM dial, were you on the dyno? The way I figure it is that I'll still need to maintain the stock stoimetric ratio, but I have no idea how to go about testing that after I put in the new injectors. Hell, I have no idea how to test that with the stock injectors?!?!?
 

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Yes you can pass smog with upgraded injectors. Just make sure that the computer as control of the fuel trim. If you have any problems with the air/fuel ratio then make sure you have a good 02 sensor. If your 02 sensor isnt any good then you wont pass smog anyways.

If anybody has any other smog questions feel free to ask Im getting my smog license in the next couple of weeks.
 

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Also you shouldn't have to mess with the AFM. If everything is working correctly then as soon as you put in the bigger injectors the 02 sensor will notice the increase in fuel. It sends that signal to the ECU. The ECU then shortens the injector pulse width thus getting you back to that magical stoimetric ratio. Larger injectors let more fuel into the combustion chamber witch means you can then run more Air into the chamber as well. All of this equals more power but should not increase Emissions if done with properly working componets.
 

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TMBJason:

When I passed smog 2 yrs ago, I was doing a "pre-test" and was told the car was close but not passing. I'd recommend everyone do a pre-test, otherwise a failed official test goes on record. (anyone correct me if I'm wrong). So, my car was not on a dyno, but had the sniffer in the tailpipe, hooked up to the machine, shop guy let me adjust my AFM (cuz I'm one those people who played with the settings), and also adjusted the air screw on side of the AFM. This does something at idle, lets more air in or something, but I figured it might be useful to tinker with. It's nice to have faith that the ECU and o2 sensor will save the day, but with alot of our motors, not totally stock configured, I wouldn't bet on it.
BTW, will the '85 ECU fit the older models ? Maybe they learned from my unit I sent down it was impossible to mod. At least they refunded my funds. The guy in Canada, Yoshio, also took a stab at modding the ECU for me, kept it for almost 2 months. No go. That darn ECU has traveled more than I have ! I hope your ECU mod works, it would be another option for lots of members.

Don L.
 

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BTW, will the '85 ECU fit the older models ?
Don, you should be able to switch up to an '85 spec EFI system relatively easy. All you should need is an ECU, harness, and a knock sensor. Hopefully your block is tapped for a knock sensor already. It should be on the intake side of the block more or less right in the middle if you want to check. You might be able to get by switching the engine harness by just adding the knock sensor circuit onto you existing wiring. You also need to make sure you have the small round type TPS (yours should have this).
 

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Hi Aaron:

So, you are saying that the '85 ECU is not just a plug and replace to the '84 models ? The other member working with EL Prototypes hopefully will take note of this. I'll be going through that darned smog check thing next few months, so I'm certainly not looking for any changes right now.
I've bypassed my MSD at the Atwater event, seems the missing and backfiring related to the MSD unit, maybe it's finally gone bad. At least the bypass was easy. Car ran great at Atwater.

Don L.
 

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Don,

I'm not sure if the plugs are the same or not (probably are though), but the 85+ cars have knock sensors. The 85+ ECUs should throw a check engine code with no knock sensor. I'm not sure if the ECU will try and run in a fail safe mode or not. It would probably be best to avoid this and install the knock sensor. If you have a 84 factory manual check the FI section (page 75 in mine) and see if the pin outs look like this (minus the knock sensor one);

http://www.cygnusx1.net/supra/library/TSRM_MKII/fi/FI_075.html

If the plugs are pinned out the same you could probably just graft the knock sensor wiring on to your 84 harness.
 

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Hi Aaron:

The '85 ECU pin outs are similar in plug design (as far as I can tell from my '84 factory manual), but the knock sensor is added on the '85, and on the right plug some of the ECT computor pins are in different locations.
Seems like what you are saying should be possible, move a few wires around, graft a knock sensor wire onto the plug.

Don L.
 
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