AEM F/IC writeup

[jdwk]

A 1.5kohm resistor will cause less of a voltage drop than a 1.2kohm, I'd imagine the miata guys played around with it before coming up with 1.2. Anything more and you may still end up out of range depending on how much air you are sucking in. I haven't done any measurements yet so who knows.
I do like the idea of getting rid of the MAF altogether, but we'll see how difficult that is. I watched a few of those videos back when I first got the AEM from swirl but like any instructions, unless you attempt it yourself right away, it fades from memory pretty quick.

My redline shift boot and armrest cover came today. Got to love Mazda putting two screws of the boot plate upside down so you have to remove the entire console to get to them. Wasn't too bad though and I took the opportunity to really clean up the console. Previous owner apparently spilled a coke, pretty gross.

 

[HighSpeed]

I have read about miata guys running no maf and using a map sensor, then the FIC converts it to a MAF signal to the ecu. I would imagine this would take a good bit of tuning to get it right because of the difference between how a MAP works vs a MAF. I would love to see an MSP with a gm 3 bar MAP or a motorola(i think) 2.5 bar MAP, I just love MAP sensors more than MAFs but MAPs can be a PITA sometimes

 

[destineal]

would that cause a cel?

 

[HighSpeed]

would that cause a cel?

I think the FIC has a program in it to change a MAP signal into a MAF signal so that the MSP ecu will recognize it. I know that there has to be some issues with it though, they read different things, so there has to be something lost in translation. But I have read of Miata guys doing it and it working fine......but only after alot of tuning and a complete understanding of how it works.

 

[destineal]

Definitely sounds worth looking in to.

 

[HighSpeed]

for your enjoyment

http://forum.aempower.com/forum/index.php?topic=23732.0

 

[MSP2k3]

Making any headway Ricktalife?

 

[Ricktalife]

I asked a friend some questions about the situation since he knows about resistors and electronic s***. As somebody mentioned earlier he suggested using a 1k and a 200 ohm resistor in a series to get the 1.2k that we need. I'm heading back to radio shack today to get a 200 ohm and hopefully I will get it wired in by this weekend.

 

[HighSpeed]

Sweet, let us know......Im eye balling the AEM pretty hard

 

[jdwk]

Ok AEM has already pissed me off. I rewired the harness, pulled out my ECU, and went to load the software and I get the message that it cannot open the file C:\Windows\System32\rpcrt4.dll.

I am fairly adept at computers, I know to run as administrator. I even took ownership of the file and opened up full control on it, but no such luck. It must be looking for a file size or other attribute that is not the same in my custom Win7 build.

There was another AEM user on their forum that had the same problem. No solution was posted. I want to reply and second the problem, so I register for the forum, but I have to wait until my request is approved. It's not an automated process like every other forum in the world.

In the meantime, I have a on old WinXP machine I can try this out on, but fairly upset I can't use my new laptop, because I am gonna have a hard time powering and driving around with a full tower in my passenger seat.

 

[destineal]

If it does require XP to run, just run xp virtually on your new laptop. problem solved

 

[Ricktalife]

Yea I luckily still have XP on my netbook so I haven't had any issues connecting that way. Though I would do like destineal suggested and run a virtual machine.

In other news, I just soldered a 1k ohm resistor to the MAF wire and still the car dies immediately, so I'm going to check my Crank sensor wires now and see if they are indeed backwards. I pray that they are.

 

[719prottege]

hope so

 

[destineal]

I hope you get it sorted out so you can be Captain of a better boat

 

[Ricktalife]

Well I switched the crank sensor wires, but it still doesn't start. I didn't have a CEL when I reconnected the bypass so I have no idea what the problem is... guess I'll give tech support another call.

 

[HighSpeed]

Well I switched the crank sensor wires, but it still doesn't start. I didn't have a CEL when I reconnected the bypass so I have no idea what the problem is... guess I'll give tech support another call.

It will probably be something that you simply over looked, and its going to piss you off. Tech support is probably the best option at this point.....so that you don't do something you will regret.

 

[Ricktalife]

It will probably be something that you simply over looked, and its going to piss you off. Tech support is probably the best option at this point.....so that you don't do something you will regret.

Well it's hard to say if I overlooked something, or was led in the wrong direction by that POS diagram. Tech support is available Monday thru Friday so I'll try to call them tomorrow probably during my lunch break. I wired in a resistor to the MAF wire, but I used a 1k for now just to see if it would suffice. I have some 100 ohm's that I will attach if tech support doesn't suggest anything else.

Oh and I ran down to advance earlier today to see if a CEL came up when connecting the box, and it did. Once again it is P0335 for the crank sensor, and I am fairly positive that I have it connected properly now so it may very well be the resistor causing the issue.

 

[jdwk]

My car started up just fine today and drives, sort of.
After a few seconds of rolling down the street the CEL came on. I turned around, gave it some gas, and it cut fuel as soon as I gave it a little bit of throttle.

I am looking at the data log now and I can see where MAF in goes just over 5 volts to 5.025 and the MAF out is a dead even 5. I assume this is the cut, althogh my injectors shot up to 125/127/130/124, which doesn't seem like a fuel cut.

The odd thing is just before the MAF went to 5, the O2 went to .989 to dead 0. Even bank 2 which is not even connected to anything dropped from .549 to .063.

I can see in the setup where I can change the MAF clamp value, but it only goes up to 5.87.

This resistor setup bothers me. If you are altering what the AEM sees, you are also altering what the PCM sees. If the PCM is seeing half the air it should, then it's going to run stupid lean. The Miata thread on the AEM forums actually says to adjust the bas map 15% to match stock, but that doesn't seem like enough.

I need to install my LC-1 before I do something stupid and blow the engine. I have no idea what the narrowband is calibrated too and apparently likes to drop to 0V.

 

[Ricktalife]

do i need a resistor on both the MAF in and out?

 

[HighSpeed]

do i need a resistor on both the MAF in and out?

That may be the problem. That or the resistor may be getting to hot and has failed you, but I doubt that, resistors are made to heat up some.