aem v1 tuning questions...

Sep 19, 2011
510
0
16
Des Moines, IA
I am in on the timing being off. I am fighting issues with timing on my v1 right now. It wont run past 6000rpm just drops all power under full throtlle, but under partial throttle i can run it up to redline. Redline is set at 7000. Been fighting it for a few weeks now. The tuner I keep having play with it keeps fucking the map up so I have one of the best tuners in the nation looking at it right now. I also have a dead spot around the 3000 mark when its coming into boost.

I do think my problems, and possibly yours are timing issues. Make sure mechanical and cps timing is spot on, then remove a few degrees of timing from the map is what I am thinking. I don't personally play with timing as I have no idea what im doing with it, so I leave that up to the tuners.

If I get my problems worked out tonight Ill try to remember to post up my results and see if i can let you know what the problem was.
 

gsxr141

Active Member
Oct 24, 2010
1,158
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rochester
thanks^. i started setting up my fuel pump relay kit and wiring in some ls1 style race coils. when we get that stuff all set , we'll see how she runs.
as far as the timing goes, we went by one of the threads that another member posted. we set the cps about 1/4" back and set the timing with the aem.
i also tried another cps, but still the same results.
you mentioned having a dead spot....... that's what my car feels like at 3,000 rpm, under full throttle. it's like the damn engine shuts off, but under partial throttle, it pulls right on through.
if we get it figured out before you guys, i'll be sure to post what we did.
 
Sep 19, 2011
510
0
16
Des Moines, IA
Okay, I had an injector unplugged. lol very simple, but fucked up a lot of things. It looked plugged in, but was out just enough to cause an issue.

Also with the aem when you are setting timing go in under the configure tab on the top of the screen. click on the ecu setup. and click on set ignition. Then at the bottom hit set timing, and type 10 into the box to set it at 10* according to the ecu. then you want to go out put your timing light on the car and adjust the CPS to 10* on the crank mark.
 

gsxr141

Active Member
Oct 24, 2010
1,158
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38
rochester
ok... now i'm even more confused......
we wired in a set of subaru sti coils today. they are wired up correctly, but we aren't getting any spark. we configured the aem to use these coils, triple checked the wiring, but there's no spark.
we have power, ground and a 5 volt trigger.
can anyone shed some light on the situation? maybe i'm missing something.........
 

Funkycheeze

Grease Monkey
Jul 3, 2009
163
0
16
Calgary
Probably won't work properly with the stock igniter. The stock coils are good, they are strong. Or use 2JZ-GE waste fire coils to clean things up a bit. I still think you need to go to a different igniter to solve the problem.
 

gsxr141

Active Member
Oct 24, 2010
1,158
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38
rochester
fixed it. :)
i had a very weak ground. i also found my body ground to be weak.
i have no more break up. it pulls clean past 6,000.
i have no tach at the moment. i have to get a msd tach adapter.

i still have the lean condition at 5k.
we think it could be one of four things....... a faulty pump. a bad ground at the pump. a pinched line. of the crappy aftermarket fuel filter i put in.
has anyone ever gotten a faulty new pump or filter?
 

gsxr141

Active Member
Oct 24, 2010
1,158
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38
rochester
Funkycheeze;2020765 said:
Probably won't work properly with the stock igniter. The stock coils are good, they are strong. Or use 2JZ-GE waste fire coils to clean things up a bit. I still think you need to go to a different igniter to solve the problem.

we're not using the stock igniter. i went with the sti coils because they are a "smart coil". the igniter is built into each coil.
 

Funkycheeze

Grease Monkey
Jul 3, 2009
163
0
16
Calgary
Check.

The AEM is very sensitive to bad grounding. I used one of those grounding 'kits' at the negative battery terminal to ground the chassis, block, head, manifold (both halves) and a dedicated ground to the ECU that is attached to the ground wires on the plug, and the case of the ECU itself.
 

gsxr141

Active Member
Oct 24, 2010
1,158
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38
rochester
yeah. i found a couple bad grounds. i got it running with the sti coils. no more break-up at 3k. only problem is, now i have no tach. :(
i have to find a way to get the tach working again.
as far as the lean condition........ i swapped out the new fuel pump for another 255 i had here. i'll get back to the tuners this week and see if that works. if not, i'm out of ideas....
 

gsxr141

Active Member
Oct 24, 2010
1,158
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38
rochester
definitely. it seems like the coil situation is fixed.. we still can't get the car to stop being lean up top. we've tried everything. the injector duty cycle goes from 30% at 3,000 rpm to 90% at 5,000 rpm. even with that it still gets lean up top. i have a new filter, i tried another 255, and my fuel lines are mint. idk what to do at this point. there's no logical reason that i should be running out of fuel with my setup.
at this point i'm going to try and build a bigger fuel line and inline filter.
 

Funkycheeze

Grease Monkey
Jul 3, 2009
163
0
16
Calgary
Are you sure the 255 will provide enough flow at the pressure you are running? Best to use a mechanical gauge and have someone watch it, the pressure should rise with boost and then stay stable once the max boost level is reached without dropping off as the RPMs increase.
 

gsxr141

Active Member
Oct 24, 2010
1,158
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38
rochester
it should be enough. i'm only shooting for 450-500 wheel.
i did just hook up my afpr kit. now i need to find out what the base pressure is.
 

gsxr141

Active Member
Oct 24, 2010
1,158
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38
rochester
ok fellas. i tried the afpr and the car still gets super lean up top. so far i have tried 2 walbro 255's, a new filter, the fuel pump relay mod, and the afpr. i have it set to 40psi with the line off.
my tuner has tried everything with the aem, but we can't get this figured out. i would think that the wideband is broken, but we logged all the runs with the aem. it clearly shows that it's commanding more fuel, but the afm graph shows it getting lean.
does anyone have any other suggestions? i'm open to anything at this point.
thanks again..........
 

gsxr141

Active Member
Oct 24, 2010
1,158
10
38
rochester
the duty cycle is 32% at 3,000 rpm and 90%+ at 5,000 rpm.
i just hooked up the fpr and gauge today. i'll see what it reads tomorrow on a test drive.
it really seems like the pump is crapping out. i tried 2 different ones, and find it hard to believe that they are both bad.
i was going to buy a mk4 denso today, until i found out that they were like $250
 

gsxr141

Active Member
Oct 24, 2010
1,158
10
38
rochester
at this point, i have NO idea what the problem is.
i tried an afpr yesterday, and it's the same. i set it to 40psi unplugged, then today it was up to 43. it also bleeds down overnight.
the car idles great, and at part throttle the afr's are in the 11's..... as soon as i floor it the afr's go down then right back up past 14.
i don't want to buy another new fuel pump if that isn't the issue. i'm honestly starting to think that the ems os fucked up.
 

Funkycheeze

Grease Monkey
Jul 3, 2009
163
0
16
Calgary
Still sounds like a fuel pressure problem. You need to get it on a dyno and watch the pressure on the FPR gauge to see if it stays steady once the engine gets to max boost, or if it drops off as the RPMS increase.