Lexus AFM

2genfun · 02-16-2012, 03:09 AM

quick question...my turbo mk3 was running fine, completely stock. i put a lexus afm on it and now it breaks up while driving normal, and seems to have a hard time idling.

cre · 02-16-2012, 04:36 AM

You upgraded the injectors or added 25% more fuel some other way I hope... Can't run more air until you've got more fuel or you're going to run lean and destroy stuff VERY quickly.

Green7mgte · 02-16-2012, 12:37 PM

are you talking housing or black box? if you replaced your stock metal honeycomb then yes, your going to ruin you engine unless you have a way of tuning. The black box used as a replacement for your kvafm (i.e my old one busted.) is acceptable and should not affect your daily driving. granted you wired it in correctly..

pandrade · 02-16-2012, 03:03 PM

from what i have heard if you put the lexus afm you can also take its injectors which already flow 550cc which both will plug and play( i would get them flow tested first, dont want a bad injector)if you dont have the injectors you'll start damaging things really quick

Green7mgte · 02-16-2012, 04:28 PM

If the lex are low impedance. I don't think they are if I recall correctly
That's something I'd check into.

cre · 02-16-2012, 07:49 PM

The stock 1UZ injectors flow around 250cc/min.... NOWHERE near what even the 7M-GE's injectors flow. The 1UZ also uses high impedance/'saturated' injectors where the 7M-GTE uses low impedance/'peak and hold'. Actually, the 7M-GE's '89+ injectors are an upgrade for the 1UZ; '89+ GE injectors (with the green top) are high impedance.

The ELECTRONICS within the 7M-GTE and 1UZ-FE KVAFM are the SAME and may be interchanged.

The HOUSING of the two KVAFMs are different. The 1UZ's flows about 25% more unmetered air. As this air is unmetered and the ECU has no way of knowing that it needs to provide additional fuel to match the airflow.... Hence the REQUIREMENT for larger injectors; It's not an option.

Green7mgte · 02-16-2012, 11:33 PM

I thought they were high impedance. I was at work tho posting from my iphone.

can you make that a sticky please. or move to the faq.

cre · 02-17-2012, 12:12 AM

Quote:

Originally Posted by Green7mgte

I thought they were high impedance. I was at work tho posting from my iphone.

You thought correctly... they are. You can use high impedance injectors on an engine which came with low by removing the resistor pack but you cannot run high impedance injectors with an ECU that's built for low (at least not without a good amount of work... often including a different ECU

).

Quote:

Originally Posted by Green7mgte

can you make that a sticky please. or move to the faq.

I'll move it to the FAQ for now. I may put together a more concise thread without all the additional chatter in its place later on. I didn't realize that this upgrade wasn't even covered in the FAQ.

cre · 02-17-2012, 12:15 AM

Ok. I've moved it to the FAQ. Everyone keep in mind that if you reply to this thread now it is moderated so your post won't show up until a staff member approves your post.

We haven't heard back from 2genfun.... Are we to assume he's busy swearing while pondering the easiest way to replace a piston with 'speed holes'?

Green7mgte · 02-17-2012, 01:05 AM

that explanation you gave, covered that question most thoroughly. It deserved a spot in the faq. Rather then repeatedly spouting it. Cheers!

02-16-2012, 03:09 AM	#1
2genfun 3" Exhaust Join Date: Feb 2010 Location: Orlando, FL Posts: 65	Lexus AFM quick question...my turbo mk3 was running fine, completely stock. i put a lexus afm on it and now it breaks up while driving normal, and seems to have a hard time idling. __________________ 88 targa. H&R springs, koni adustable shocks, 18" wheels, d&s rotors, goodrich brake lines, 7mgte in progress...

02-16-2012, 04:36 AM	#2
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	You upgraded the injectors or added 25% more fuel some other way I hope... Can't run more air until you've got more fuel or you're going to run lean and destroy stuff VERY quickly. __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

02-16-2012, 12:37 PM	#3
Green7mgte Supra Forum Moderator Join Date: Nov 2009 Location: Green-Ohio Posts: 1,297	are you talking housing or black box? if you replaced your stock metal honeycomb then yes, your going to ruin you engine unless you have a way of tuning. The black box used as a replacement for your kvafm (i.e my old one busted.) is acceptable and should not affect your daily driving. granted you wired it in correctly.. __________________ 92 Ma71 7mGTE Auto. SafcII Supra FAQ Supra MKIII FAQ Classified Section guidelines : Last edited by Green7mgte; 02-16-2012 at 12:40 PM.

02-16-2012, 04:28 PM	#5
Green7mgte Supra Forum Moderator Join Date: Nov 2009 Location: Green-Ohio Posts: 1,297	If the lex are low impedance. I don't think they are if I recall correctly That's something I'd check into. __________________ 92 Ma71 7mGTE Auto. SafcII Supra FAQ Supra MKIII FAQ Classified Section guidelines :

02-16-2012, 07:49 PM	#6
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	The stock 1UZ injectors flow around 250cc/min.... NOWHERE near what even the 7M-GE's injectors flow. The 1UZ also uses high impedance/'saturated' injectors where the 7M-GTE uses low impedance/'peak and hold'. Actually, the 7M-GE's '89+ injectors are an upgrade for the 1UZ; '89+ GE injectors (with the green top) are high impedance. The ELECTRONICS within the 7M-GTE and 1UZ-FE KVAFM are the SAME and may be interchanged. The HOUSING of the two KVAFMs are different. The 1UZ's flows about 25% more unmetered air. As this air is unmetered and the ECU has no way of knowing that it needs to provide additional fuel to match the airflow.... Hence the REQUIREMENT for larger injectors; It's not an option. __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

02-16-2012, 03:03 PM	#4
pandrade 12psi boost Join Date: Mar 2011 Location: fort myers florida Posts: 345	from what i have heard if you put the lexus afm you can also take its injectors which already flow 550cc which both will plug and play( i would get them flow tested first, dont want a bad injector)if you dont have the injectors you'll start damaging things really quick

02-16-2012, 11:33 PM	#7
Green7mgte Supra Forum Moderator Join Date: Nov 2009 Location: Green-Ohio Posts: 1,297	I thought they were high impedance. I was at work tho posting from my iphone. can you make that a sticky please. or move to the faq. __________________ 92 Ma71 7mGTE Auto. SafcII Supra FAQ Supra MKIII FAQ Classified Section guidelines : Last edited by Green7mgte; 02-16-2012 at 11:38 PM.

02-17-2012, 12:15 AM	#9
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Ok. I've moved it to the FAQ. Everyone keep in mind that if you reply to this thread now it is moderated so your post won't show up until a staff member approves your post. We haven't heard back from 2genfun.... Are we to assume he's busy swearing while pondering the easiest way to replace a piston with 'speed holes'? __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

02-17-2012, 01:05 AM	#10
Green7mgte Supra Forum Moderator Join Date: Nov 2009 Location: Green-Ohio Posts: 1,297	that explanation you gave, covered that question most thoroughly. It deserved a spot in the faq. Rather then repeatedly spouting it. Cheers! __________________ 92 Ma71 7mGTE Auto. SafcII Supra FAQ Supra MKIII FAQ Classified Section guidelines :

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