AEM EMS cam signal

[Weiss]

Why does AEM ems not like to pick up cam signal..Ive looked all over the AEM forum with no luck on how to fix..I get crank signal no problem its just no cam signal..

Filed down the bracket to move the cam signal closer-no luck
moved the aem away from the metal plate-no luck
Also set sync error r/m to 0-and nothing

Now on the stock ecu its 100% fine, warm the car up on the stock ecu and switch over to the aem and it will work fine, but will get a break up between 2800-3k(lack of signal) then again in 6th gear at 3k

I have a 2000 2.5rs with a 04 wrx harness merged into factory harness, built engine, BC cams, aem 3.5map bar, aem iat sensor, power enterprise 800cc injectors. Im running the 1.19V on the AEM

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[sense of nature]

Curious as to why you didn't just run the wrx ecu?

[Weiss]

Originally Posted by sense of nature

Curious as to why you didn't just run the wrx ecu?

I use the wrx ecu thats reflashed just to pass state inspection..The stock ecu is making out on 22psi..AEM to make real power and better tuning..

[lennybootzz]

im having the same problem with my aem on my 04 sti i called aem they gave me some run around answer...

i had heard you have to file down the cam sensor too it helps!!!! If i ever get home early enouph from work i will be trying that next...

I hear JR & turbo mike bolth have experience with aem you can try them!!! lmk what happens

p.s. make sure you have MOds A REV C box its the "Newer" version!

[Brydon]

File the crank sensor as well. You might want to try new sensors too.. The AEM is more sensitive to noise then the factory ecu. I had the same issue when I changed cams. I filed the sensors closer and it runs great out to 7500 now.

[Weiss]

I got plenty of crank signa, so I don't think I gotta move it closer..its my cam signal that fades in and out, I'm gonna try 1.21v..

[Weiss]

Got home form work it was about 54* outside, slapped the aem while the car was cold and it fired right now...let it warm up and took it for a drive no bucking around 2800-3...Seems when its cold there is no cam signal..

[lennybootzz]

my tunner seems to think its fuel im going to be adding a second walbro 255. I have the kelford cams they seem to have more trouble

[Weiss]

mine is cam signal, you can watch it come and go...if its warm its 100% fine.

[Element Tuning]

The RS and older Imprezas have a very weak trigger signal and I know on the Hydra we have to run a special circuit for those models to condition the signals so they are adequate. This is why our RS Hydra computers aren't the same as the WRX Hydra computers.

Thanks,
Phil Grabow

[Weiss]

Originally Posted by Element Tuning

The RS and older Imprezas have a very weak trigger signal and I know on the Hydra we have to run a special circuit for those models to condition the signals so they are adequate. This is why our RS Hydra computers aren't the same as the WRX Hydra computers.

Thanks,
Phil Grabow

I have a 2004 wrx harness mated into the factory harness tho.

[Bluedemon_II]

My 04 Sti has the same problem, it has a very intermittent cam signal that comes and goes when it wants.

If you set the Sync ignore to 0 you are telling the ems to look for sync everywhere on the rpm range. Set it to 100 or 200. Mine starts up fine, sometimes it takes a little longer but it starts.

I filed the sensors down but it didn't make much difference. Right now I'm running with the avcs turned off out of fear of a malfunction and vent valves.

Called aem and they say that there is nothing wrong with the ems.

I'm also running brian crower cams, stage 2. Seams that the cam profile at the sensor area is different from stock, still it is strange that the stock ecu had no problems in that area.

There is an other Sti in my island that has the same cams and the same issue, but he has it worse than me.

[Element Tuning]

I'm also running the BC 280 cams and they work perfectly fine with my Hydra EMS so I don't think the problem is with the cams pickup markings. The signal conditioning is critical on the EMS and on the 02-04 WRX the magnetic pulse is a little weak. On the 04+ STis it's also week and there is an option on the Hydra to use the "sync pull up enable" for that model.

Good luck guys but it's an EMS issue.

[project_skyline]

+1 AEM likes to think their stuff is the best and has no issues.

[pavel_chembar]

There are some different types of sensors making by Subaru. Sensors of JDM WRX it is not the same as USDM WRX, and quantity of sensors different too. Are you sure that sensors on your RS is the same on WRX 02-04?
You changed harness. It is from WRX. WRX for what market? USDM? JDM? EUDM? AUS?

[Bluedemon_II]

Phil, if the problem lies with the stock 04 cam sensors, could the problem be solved by getting newer cam sensors? I'm attempting to find some help on a electronics oriented forum. So far I need more info on the issue to have a solid background electronics wise.

[Weiss]

Originally Posted by pavel_chembar

There are some different types of sensors making by Subaru. Sensors of JDM WRX it is not the same as USDM WRX, and quantity of sensors different too. Are you sure that sensors on your RS is the same on WRX 02-04?
You changed harness. It is from WRX. WRX for what market? USDM? JDM? EUDM? AUS?

Everything is USDM. Everything sensor wise is 02-05 wrx, the harness is just so all the dash stuff etc works. like i said when its above 50degrees the car will start no problem, its when its below 50 it will not like to start.

[pavel_chembar]

Originally Posted by Weiss

Everything is USDM. Everything sensor wise is 02-05 wrx, the harness is just so all the dash stuff etc works. like i said when its above 50degrees the car will start no problem, its when its below 50 it will not like to start.

Is wire from sensor's connector a single whole?
Did you do good ground of the harness? You can try to ground importent parts additionally.

[Weiss]

Originally Posted by pavel_chembar

Is wire from sensor's connector a single whole?
Did you do good ground of the harness? You can try to ground importent parts additionally.

what do you mean is the sensor connect a single whole.

[Bluedemon_II]

I'm still thinking if it is possible to use an other cam sensor that has 3 cables like the stock one but with a better sensing element. Because there is no way to modify the box, an inline amplifier is possible but requires a good electronics knowledge.

[Brydon]

Originally Posted by Bluedemon_II

I'm still thinking if it is possible to use an other cam sensor that has 3 cables like the stock one but with a better sensing element. Because there is no way to modify the box, an inline amplifier is possible but requires a good electronics knowledge.

Amplifier will not help. The AEM is actually too sensitive. Decreasing the gap on the sensor decreases the signal. The AEM needs a filter for noise with low amplitude.

Nevermind this only applies to 02 -05 WRX.

[Bluedemon_II]

Originally Posted by Brydon

Amplifier will not help. The AEM is actually too sensitive. Decreasing the gap on the sensor decreases the signal. The AEM needs a filter for noise with low amplitude.

Nevermind this only applies to 02 -05 WRX.

Even so, where could I get a noise filter. Something ready made that I could just hook it up?

[Brydon]

Originally Posted by Bluedemon_II

Even so, where could I get a noise filter. Something ready made that I could just hook it up?

No where that I could think of. I electrical engineer could build you one easy enough. Just need a o'scope. Try praying on college kids to help you out.

[Bluedemon_II]

Originally Posted by Brydon

No where that I could think of. I electrical engineer could build you one easy enough. Just need a o'scope. Try praying on college kids to help you out.

I'm in college. This is becoming to be more troublesome than expected. I will scrap the avcs system until something is comes out to fix this issue.

[Weiss]

bump I wanna finally get it tuned on the aem and make more power