AEM EMS problems

[HobieKopek]

Originally Posted by HobieKopek

First off lemme introduce myself. My name's Andrew. The Lancer Jeff at ILP Performance was trying to get running is mine. Well, thanks to Mike W. It's running and driveable now, however it's BARELY running and barely driveable.

There's a bunch of problems and here's what we're thinking. We're running off a MAP sensor now (a 3 bar sensor) and the MAF is making a nice shelf decoration in my closet. Apparently the stock MAF has a barometric pressure sensor in it that the EMS isn't getting a signal for now. I don't know if or how much that could effect its running, but it's a possible variable. Now here's a description of some of the problems so hopefully we can shed light on what's really going on.

First off I'm running rich as hell. 12:1 AFR, car seems to love it, doesn't choke on the fuel, but I can smell unburnt fuel in her exhaust and she spits black smoke. That's not a problem so much as detail on the scenario. Here's the BIG problem.

When she builds up boost she can't pass 5psi. 8O Till then it's fine. Spools nice and low (a bit below 3,000rpms) and builds to about 5psi then leans out rapidly and makes no power. I don't have logs of this, but Jeff explained to me that they IDC went from 25% (Walbro 2g GS-T fuel pump feeding 440cc injectors @ 25% IDC = PLENTY of fuel) to next to nothing (or maybe nothing...I forget.) It's like hitting a fuel cut while driving only my engine is at far more risk. This is the major problem.

As someone else mentioned in another thread, the tach is somewhat jumpy, but my real concern is that she sometimes revs to something like 4-5k for a few seconds and then drops back down to her given 1k idle. On occasion she randomly stalls. Coming to a stop in neutral she's died while idling and breaking a few times, and I'm getting quite good at turning the ignition while steering with a locked wheel and stepping on the brake...but I shouldn't have to be. :?

I'll lean her out a bit once I get a laptop (my current one's battery holds no charge). By next week I'll try to get some logging done on my drive to work, and I'll take a little fuel out of the mix to try and make the smell of my commute (as well as my gas mileage) tolerable. If you need more details of the setup I'll provide them or have Jeff provide them (I know the parts and most of how they're set up, but not even close to everything). We've had few successes and several problems with the EMS so far. If it wasn't for the possibility of actually having it working properly and providing such a wide range of tunability I'd have scrapped it already. I'm hoping someone can give me a good reason why I should keep it by helping to solve the problems it's causing.

If maps or logs are needed I'll try to provide them as soon as I'm able...probably within the next two weeks. Until then I'm hoping I can get some possibilities, suggestions or fixes.

I originally posted this on the AEM EMS tech forums but I'll give it a shot here for answers too. Someone out there has to have a unit running (Unless I'm the only one running it on a Lancer at present). Anyway, lemme know.

Suggestions so far: Vacuum leak (unlikely), MAP sensor reading incorrectly (possible but unlikely) and finally that the EMS has been known to have problems with boost correction tables.

Right now it's set up with boost correct so this is looking like the most likely issue. I'm taking her back for a Clutchmasters Stage 4 clutch install and hopefully for more tuning around the 20th of June, so I'd appreciate any help anyone could provide. I've had more than a handful of problems already with the EMS (just getting it running too my mechanic a month because AEM screwed up some pin outs due to differences between the Lancer and 4cyl 3g Eclipse which use the same unit). Anyway...little help?