aem v1 tuning questions...

gsxr141

Active Member
Oct 24, 2010
1,158
9
38
rochester
hey all. i recently had my aem ems installed and started doing some tuning.
when we started i was running fic 630cc injectors and the stock fuel pump.
we ran into some stumbling around 2500, and it leaned right out at 5k. at higher boost levels it leaned out earlier, about 4500.
we tried bumping up the injector duty cycle, but it made no change in the lean condition.
at this point we thought the pump was running out of steam so i installed a new 255 and a new filter........ we still have the same problem, it leans out up top and upping the duty cycle makes no difference.
is it possible that there's something wrong with the aem unit? possible a bad injector driver?
the car is down for a rebuild right now, but will hopefully be up and running in a couple weeks. .......
any help is greatly appreciated.............
 

gsxr141

Active Member
Oct 24, 2010
1,158
9
38
rochester
i also wanted to add..... the rich/stumbling condition seems to be intermittent. we had it tuned out while road tuning, only to come back on my drive home.
should i be looking at old/worn factory wires?
 

gsxr141

Active Member
Oct 24, 2010
1,158
9
38
rochester
from everything the tuner has said, we're running out of fuel. the stock coils should be good at this power level. we're going to see how many volts are actually getting to the pump when the motor goes back in.
 

gsxr141

Active Member
Oct 24, 2010
1,158
9
38
rochester
one of alberts 60-1's. we were tuning at 11psi. any higher and the lean condition starts earlier. i'll see if i can get him to download the map.
the mods are.... 60-1 turbo, 630cc fic injectors, bic ddp, full 3" exhaust, 255 walbro, k&n filter.
 

hvyman

Dang Dude! No Way Man.
Staff member
Apr 17, 2007
12,568
0
0
Fullerton,CA
Sounds like either lack of fuel pressure or bad tune.

The 60-1 is not going to outflow 630 injectors. Esp at 11 psi.

My 6262 doesn't outflow my stock 370 at 11 psi and my turbo flows more air.
 
Sep 19, 2011
510
0
16
Des Moines, IA
Have you setup injector latency values? both my AEM's I had to set the values even after selecting the right injector, as AEM's values are wrong. On my new car it wouldn't let me get the idle leaned out, on my white car it would stumble all through the rpms
 

gsxr141

Active Member
Oct 24, 2010
1,158
9
38
rochester
I'M BACK. LOL

ok guys, i'm still having a few issues......

at full throttle, as i get to 3k the car just stops and the tach drops. it is fine at half throttle, but
every time i try it at full throttle it happens.
i have tried new wires, different stock coils and new plugs. i even gapped the plugs tighter.

i've done some searching and found some things about the aem not liking the stock ignition.
i plan to install aftermarket coils, but would love some input.
thanks.....
 

Funkycheeze

Grease Monkey
Jul 3, 2009
163
0
16
Calgary
- Try a different CPS. Check for sync errors as you log the ignition parameters with a laptop hooked up.

-Do the 2JZ-GE coil and DH61 igniter mod. Much better ignition system than stock, and it runs a lot better with the AEM box.
 

gsxr141

Active Member
Oct 24, 2010
1,158
9
38
rochester
thanks guys. i tried another cps, but it does the same thing. it will roast the tires in first, but anytime there's "load" on the engine, it dies right out at 3k.
it's perfect at half throttle, but as soon as you floor it, it acts up.
i have a set of sti coils that i'll be wiring in.
we'll see what happens.........
 

aljordan

LEADED FUEL ONLY
Jul 14, 2005
466
0
0
47
Indianapolis, Indiana
www.apeserver.com
Did you ever get rid of that stock pump??? a stock pump needs upgraded whenever the turbo is upgraded. Even a mild ct upgrade will require a new pump. One can see this by looking at fuel pressure under boost. It'll slowly drop off. Drop in one of those new Walbro e85 compatible pumps and not upgrade again for a while.

Also, can you take video of the stumbling issue? My car would do this at around 33° or timing and around 3k rpms. I think it's more of a timing thing than being around a certain area of the tach. The car would act as if power was removed from the ECM for a split second.
 

gsxr141

Active Member
Oct 24, 2010
1,158
9
38
rochester
i have a walbro 255 and 630 injectors.
i've tried new plugs, wires, a different cps and different coils. no change at all. if i get on it off the line it will rip the tires loose, but ANY time i'm going full throttle through 3k rpm it dies right out. partial throttle is perfect. i'll try to take a video of it tomorrow.