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I turbo'd my u2 rr with a t25. Simple simple kit. Now the problem I'm having is it throwing a code (Crank shaft position sensor a circuit malfunction) and when I clear it as soon as I go into boost it comes back on. My mechanic isn't able to locate the problem. He contacted aem and did what they told him to do but still nothing. He is going to contact them again in the morning but I was wondering if anyone else had this same problem. This simple turbo build ended up being a huge money pit. Any help will be great.

Also on a side note, does anyone know their settings for the aem FIC? I'm having problems between 2-3xxx rpm. I think it has to do with that code but im brand new to the turbo game and just am dying for help
 

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A simple turbo kit is never simple. Few companies put together full "kits" that actually think out all the issues that make the kit complete. Usually you need to think through the issues.

I will assume you are clearing the code with a self diagnostic screw? If you are taking that approach you are not really clearing the code. It's still there, the ECU is still scanning to see if it is an issue, and if the code is still an issue, it will show back up as a CEL on your dash. The only true way to clear out a code on an ECU is to have a consult/computer hooked up to the diagnostic port of the vehicle, then electronically remove the code.

With that being said, and hopefully I'm still on the right track, the ECU is probably designed for a flywheel with a different tooth count, you have a poor reading CPS, bad continuity in the signal wire, or a bad ECU. One of those is most likely causing the CEL to turn on. Start by exchanging the ECU, you probably spent a crap load of money on that AEM unit, they should back their products and exchange another ECU for you at no charge. If it still shows up with a new/replacement ECU, you know you need to start troubleshooting those other areas.


Last, your mechanic or AEM should be able to give you some insight on basic maps you can plug in for very simple functional tunes. Keep in mind, it might not just be the ECU or the tune causing problems from 2k-3k RPM. You could have boost leaks somewhere, you could have a crap turbo, you could have a weak fuel system. Any properly tuned boosted car is like a work of art and every detail needs to be taken into consideration.

So take your time, read as much as you can, talk to people who have used similar parts and what has worked for them. Chances are you will not find a whole lot of people on this forum using the AEM ECU's.
 

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Sounds like you wired the CRK sensor wrong. HOW did you wire it? Its a Mag sensor and you should be intercepting all the + normally, but only TAP the MAGI - into the sensor wire, DONT intercept it.... and you do nothing with the MAGO-
 

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Just fyi for anyone who uses fic in the future or if you never figured out your issue, you do not intercept or tap the crk sensor. you intercept the cam reference from the dizzy with cam hali 1 on fic and intercept cam position from dizzy with crk hali 1 on fic. cam reference is low res like a typical cam sensor and cam position is high res. you will get much much much higher resolution this way as opposed to just tapping the ckp signal
 

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/\/\ not really, you need to intercept the Cam AND crank sensor to really have timing control. Just intercepting cam may be nice for RPM signal but will barely give you any timing control. I'm wired into the CRK as mentioned above with 0 issues and plenty of timing control
 

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I don't know about the 32bit ECUs, but on the earlier (94-99) OBDII ECUs, the crank sensor (located in the bellhousing of the transmission) is not used for timing pickup/control. It is only used for a reference for misfire monitoring.
 

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yeah thats the thing if your modifying cam signal for timing and the crk sees that different in relation to its own readings its going to get real confused fast and think misfire if you adjust too much timing. When you tap into it, the FIC modifies its signal accordingly as the cams to keep it happy over a wider range of timing adjustment.
On some Toyotas you gotta wire a resistor into the CRK wire cuz its a really sloppy signal and Toyotas suck.
 

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the crk sensor on our cars was not designed to support anything other than obd2 and was an afterthought, there are two pickups in the distributor and they are both designed to support the ecu, thats all im saying ;)
 

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Cam hall intercept the reference to pull timing. I had to tap the crank hall in, into the fic, to the dizzy position, to get rpm signal in the fic. That was on manual ecu with auto transmission.

Auto ecu just had to intercept cam hall reference for timing and rpm.

Injector response time 1012. That should get good start to take that hiccup out of the tip in acceleration.

Both 96 AT and MT ecus
 
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