I decided to go for a nice drive to grab some groceries and after returning to the car with my rations it wouldn't start.
Uh-oh.
If the motor doesn't start it could mean a crap load of things. Luckily I've got gauges to give me an indication on wtf is going on.
I tried to start the monster again, it wouldn't start. After a few attempts it would start but idle very very roughly then die. Looking at my gauges gave the following info:
- Rich condition. The A/F gauge was reading rich.
- Ignition was working as displayed by the ScanGauge.
- There was sufficient air going to the engine as the MAF signal was normal, displayed by the ScanGauge.
I plugged in the by-pass harness which I always carry in the car. The car starts up!
After a perilous drive home trying not to go into boost I checked the calibrations and readings of the AEM FIC. All cal files were there and the calibration was not lost... Interesting.
Then, I checked the FIC's on-board gauges and discovered the problem... The load gauge (MAP) was at 35psia.... With the engine off, the absolute pressure should only be about 14psia in my part of the world.. So there was a problem with the on-board MAP sensor.
I tried re-flashing the firmware in hope that it might rectify the problem but it didn't. After some forum surfing it turns out this isn't an uncommon problem. Rats.
The FIC is no longer within its warranty period and from forum posts, fixing the sensor doesn't work and sending it back to AEM is costly. So what to do...
Got it! Let's use an external MAP sensor as an input to the FIC and use that for tuning! Stay tune to see if this solution works!
Wow so after talking to you on your post on fuel trims I just recieved my FIC this morning.. Guess what??? Its reading 35psia on the table. So pissed right now! Paypal Claim here i come!
ReplyDeleteOh..! Terrible! Make sure you let AEM know of the issue; give them your unit's S/N as well just in case it could be a defective batch.. Something AEM to sort out..!
ReplyDeleteIve sent it back to the seller already but i should be buying a new unit from AEM.. going to be hit by customs charges now too. starting to wish i hadnt sold my emanage and tried the aem software because i love it and theres no going back! lol
ReplyDeleteDid you wire in a different map sensor? And did it work? I sent my fic in a few times and it has failed over and over. Never even got to drive my truck in boost. I know this thread is old but I hope you can help. Thanks in advance.
ReplyDeleteHey there! Thanks for popping by! Indeed my blog is a bit old, but I'm still around to answer questions!
DeleteYES - I did wire a different MAP sensor! There are two posts named "Tuning: Re-tuning with a Temporary MAP Sensor" Parts 1 and 2.
I built my own MAP sensor! But I ended up getting a new FIC anyway. But what I did, I kept the programming of the temporary MAP sensor and used it along with the FIC's toggle switch, where you can switch between two different tunes.
This meant, if the onboard MAP sensor dies (again), I won't be stranded anywhere and I can switch to the temporary MAP sensor AND temp MAP sensor tune to get the car driveable again!
Check out those posts and see if you can use an external MAP sensor!
All the best!!
How exactly did you "wire up" a different map sensor? I did read both blogs and I did not see how you wired a different map sensor? Mine just took a crap too and I want to wire up an external map sensor or atleast replace it my self.
ReplyDeleteHey there! Welcome! Probably should have made it clear when I wrote this was that it was more of an "alternative" load signal, rather than "temporary MAP sensor".
DeleteThe AEM FIC uses it's onboard MAP sensor as the main reference point or load for tuning. To get by, I used the MAP signal from my boost gauge (which reads manifold air pressure) as the load and used the MAF map to tune it. (https://friedrice.blogspot.com/2014/03/modification-re-wiring-temporary-map.html)
What I haven't wrote about was that I actually built a MAP sensor from scratch using integrated circuits which worked a treat. I then used it as the main load (MAF load) to tune. With the onboard MAP sensor dead, you can't tune directly using MAP. So the work around is that you tune MAF with a MAP sensor and adjust the map accordingly. Although the signal was much more 'cleaner' than then the boost gauge, tuning was painful.
In the end I managed to source another AEM FIC but, I loaded two tunes - one normal and one with the back up MAP tune and maintained the wiring of my back up MAP sensor. So if the car doesn't start because the MAP sensor died again, I can flick the switch and the back up tune would kick in. The MAF/MAP tune would get by, runs a little more rich but definitely not performance orientated.
Hopefully that clears things up! See how you go with using the MAF map (with an external MAP sensor) for tuning!