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Discussion Starter #1
Ok so heres the situation at hand. (im running lean) on a brand new motor and cant adjust the fuel.........

So heres the whole story, my 7mgte has 550 cc RC injectors aeromotive FPR walbro fuel pump and a lexus MAF. I also have a apexi airfuel controller. My motor worked great before the rod knock and I had it tuned at a dyno shop. All my HI throttle numbers were in the negatives on the apexi and Lo throttle numbers were in the positive and I ran around 11’s AFR. I have a lot of other upgrades as well but am not going to list them to many…..

So the motor blow up and I got another block and another head. I had the machine shop do all of these things

Hone the block, install balanced rods, pistons, and crank with new bearings. O ring’ed the block. Balanced the crank pully and the flywheel and lightend it by 4 pounds balanced the clutch too. As for the head it got pressure tested and machined flat, ported and all new valve stuff. All other stuff for the motor got heat tanked and cleaned very much. All new gaskets for the motor HKS head gasket and arp head studs. About 5000$ worth of stuff and work. So its all the same fuel and other stuff on the out side of the motor and for some reason im running lean. At idle and at any RPM. I have a patch harness that I bought so I could splice in the Apexi afc and avcr. I double checked the wiring and its right. I took the patch harness out and hooked up the ecu straight to the motor and im running 17 AFR. I only checked it that way while idleing, to scared to drive it that bad of afr.

So I have to add like 30% fuel just to keep it steady at 15 AFR and that’s to lean on a brand new motor. I only got like 60ish miles on it. But I have to drive it to tune it. I did a leak down test and I have no vacume leaks at all even in the intercooler set up. My FPR is set to 25 and when you take the vacume off of that it goes to 35 like its supposed to. My timing is perfect on 10 when the jumper wire is in and 15 when its out. I keep throwing codes 51 and 52. ones a AC code so that don’t matter and the others a Knock code witch is ok cause im running lean, those are the only codes at all. I just don’t get why this is happening? I just put 5 grand into this motor and I want to baby the F*&^% out of it and I cant even do that…….. please send me your questions and comments so I can figure this out. WHY WOULD YOU RUN LEAN LIKE THIS please forgive me but I have to post this on 2 different forums that I belong to so that I can get the maximum amount of feed back. Here’s a link to the build thread that I made. This is a 91 turbo 7mgte.

Andrew

http://forums.celicasupra.com/showthread.php?t=29835
 

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KBR
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2,910 Posts
dayumn!!, this is another bad ass MKII w/ a 7MGTE :) man.. now I start to miss my MKII's.

anywayz, maybe you should double check the adjustment on the LEX AFM and the pulse width of Fuel Injectors, coz there might be a possibility that one of the injectors are not flowing right or you'll probably going to need a bigger set of injectors.

also, what turbo are you using?? I'm pretty sure its not a stock CT26..


aite, peace.
 

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JZA70 448 rwhp everyday
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you have checked for air gettin in after the AFM? That or compaire teh AFM signal to what its supposed to be, mabyee injector wiring causing an injector or 2 to fail.

~scott
 

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Discussion Starter #5
dayumn!!, this is another bad ass MKII w/ a 7MGTE :) man.. now I start to miss my MKII's.

anywayz, maybe you should double check the adjustment on the LEX AFM and the pulse width of Fuel Injectors, coz there might be a possibility that one of the injectors are not flowing right or you'll probably going to need a bigger set of injectors.
also, what turbo are you using?? I'm pretty sure its not a stock CT26..
aite, peace.

well me lex afm has not been touched since i drove the car last time. i have never adjusted it. i should check the pulse of the injectors.... O and im running a stock ct-26 with the upgraded internals, 61 trim? i got the 550RC's and those worked great before.


you have checked for air gettin in after the AFM? That or compaire teh AFM signal to what its supposed to be, mabyee injector wiring causing an injector or 2 to fail.

~scott
all the wiring for the injectors is correct.

fuel pump relay by passed or jumped mod.

Whats that? i have a walbro 255, the upgraded one. my whole fuel system is upgraded so i wouldnt have the problem, all these things worked great before the new motor.
 

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Discussion Starter #6
ok so then i need a second set of eyes to look at my motor. i need some one to tell me if i did some thing wrong. ill have to post in the pacific north west section then.
 

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A wideband O2 sensor will randomly go bad, and when they go bad they read lean. Might as well check that. Is the motor running smooth/normal? I just had an issue with my IS300 where I put brand new plugs in the car and it was running lean as fock. Regapped them and still lean. Replaced all them again with new and that fixed the problem.
 

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Discussion Starter #9
A wideband O2 sensor will randomly go bad, and when they go bad they read lean. Might as well check that. Is the motor running smooth/normal? I just had an issue with my IS300 where I put brand new plugs in the car and it was running lean as fock. Regapped them and still lean. Replaced all them again with new and that fixed the problem.
the motor runs a little rough and i get some smoke out the exhuast like running to lean.
 

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Discussion Starter #10
O and by the way: when i start the car in the morning or after work the other day its rich for a couple of minutes while the motors cold, but when it gets warm then it gets hella lean.
 

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if i read it right the only thing that i can think of is that you had the head ported after you got it tuned???
more are with x ratio = lean
:1poke:
 

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Discussion Starter #12
heres some pics that i just took of the wide band and my number one spark plug. maybe that might show some thing to some one else but i can only tell that its all white.



 

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Discussion Starter #13
the spark plug has like 50ish miles on it. the wide band has like 2000 maybe from my last motor. Im really starting to think that maybe the wide band plug is bad. im going to barrow a friends LM1, (god i hate those things LOL) tomorrow and test it out. we will see if my wide band is good or not.
 

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JZA70 448 rwhp everyday
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that sensor color screams lean so im guessing its fine. Check your o2 sensor out. If your car runs rich at start up idle thats before the o2 sensor is sending to the ECU. In the tsrm there is a check for the o2 sensor readings, but im too lazy to post a link, its in the EFI section.

~scott
 
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