^^ How To: AEM F/IC-6 Install, Tuning, and Help Thread

I'm only using the crank signal, 2 years now. I would get a weird hesitation with the cam hooked up. Can't say what yours will do.

 

How rich are you guys able to run in close loop with enrichment?

Ive seen a few comments that seems to indicate that going any more than 13AFR can lead to issues and even fuel cut.

 

It can go as rich as you want. You need to balance the O2 and Fuel map so yours trims are 10 or less. @Shortman5

 

cool. Anybody know how far the stock injectors can go before they run out? I know the stock size fuel pump is plenty. 11AFR 9PSI 5500RPM is no issue.

 

I was seeing 80% duty cycle at 4200 rpm with a stock supercharger.

 

Just curious what timing advance you guys are seeing on your OBD reader. Ive read that when tuning for larger injectors through the MAF it actually increases timing because you’re altering the load table.

I’m not sure if this is the way the FIC works but I’d be interested to know.

 

Seeing what on the Obd2 reader?

You can clamp the maf map table and it will not see higher signal voltage. The Fic has a Map sensor to calculate load.

Also you re scale the fuel map by X % and the ecu is none the wiser.

 

Fixed. I was reading that ignition timing is based off of MAF and RPM etc. to calculate load. If you tune the MAF to inject less fuel with larger injectors it effectively reduces the “load” the ECU sees. This in turn increases timing on the base maps.

 

Here. Never mind the product they’re trying to sell. I’m more interested in the information here.

https://movichip.com/maf-tuning-pluses-minuses/

 

I remember something like this with the Apexi Afc on my Sr20 back in the day.

Don't forget the Ecu is always advancing timing above 3000rpm then listening for knock and retarding timing. The ecu then extrapolates this info for the timing map below 3000rpm when the knock sensors are off (too much mechanical noise that causes false signals).

 

Ive heard this. And that may be true. But the reality is that since we can’t get into the ECU we will never know how it’s actually programmed. As far as I’m aware it’s all pure speculation. But I could be wrong about that.

I want to add that when I’ve seen people comment on the timing being reported on their OBD devise it’s almost always around 11-13 degrees advance mid RPM. This is what I see. But around 4000 it jumps up to 17-19 and the increased power is felt.

Ive been wondering if these ECUs were tuned for 87 and fuel economy how much more timing is possible. It doesn’t matter how rich you can get in the mid RPM. more power is felt when the timing jumps in the upper RPMs. I’m just assuming the ECU is holding back for one reason or another.

I’m sure there’s more going on as far as engine control and power output than just fuel/timing goes. I’m really just thinking out loud.

EDIT: Just from my experience I’m not sure that you’ll get any better than 11-13 advance in the mid RPM boost. Im just assuming that that’s as advanced as it will run because that’s what it was mapped for based off 87, fuel economy, etc.

 

You have to take into account how much retard you are running at any specific rpm/load.

Both the 7th and Fic have timing retard maps. Your stock ecu/obd2 reader do not know the timing signal has been altered. The information has been changed before the Ecu ever reads it. So hypothetically, if you are boosting 7 psi with 7° of retard and the Obd2 reader is saying you have 13° advance, you are really at 6° advance.

Timing definitely makes power. Too much makes problems. It's a delicate dance.

 

The only area I’m retarding the timing is 4000-5500 due to ping at 1 degree. I understand what you’re saying as well.

Actually, it sort of confirms what I’m wondering. If I can add retard across the map and the timing advance does not change on the OBD reader that sort of confirms it’s running as advanced as it possibly can.

For example if 3000-4000 is showing 11-12 with and without retard added in the piggy map it’s evidence that it’s running as advanced as the stock ECU will let it go due to the base timing maps.

 

Yes. That's pretty close.

You should read the Urd tuning guide.

I'll regurgitate from faded memory. Timing control has a certain range. Meaning it can only retard/advance so much. To make things worse, that range was designed/tuned for natural aspiration and low octane.

Now we boost it. The NA ecu sees the maf value change and knock values also increase. The Ecu actually knows to reduce timing, but it has a limit to how much. It simply wasn't allowed/tuned to go that low. So now we use the piggy back to alter the signal and delay it by X degrees. This gives the Ecu room to lower Timing. It has now been allowed (unknowingly) to reduce timing more to compensate for knock.

Just because we gave the Ecu more room to retard, doesn't mean it needs to. So in your case, 11-12° is the most it can run based on the stock maps.

 

Ive read those. I’ll keep my thoughts to myself on them.

Again, just thinking out loud.

The stock ECU is seeing way more CFM through the MAF for the RPM/TPS range. I wonder if this is Part of the reason why the ECU seemingly drops timing in those areas.

It just seems to be sort of inconsistent. Timing should start on the low end and gradually increase as RPMs increase. Except what we get is a flat mid range.

Ideally, with a supercharger, you want a solid pull from low RPM all the way to the top. this is all probably multifaceted. With such a small pulley and narrow belt slip is inevitable. Ive always thought that I could hear a hint of slip in the mid areas. That could potentially be contributing to the flat feeling mid range.


IDK. Maybe it’s about time for a supercharged LS swap.

 

Got an intermittent problem, thinking something with the aem is causing it. Sometimes the fuel cut works, other times the truck wont, and idle sits higher than regular, maybe by 200 rpm, the rpm has been as bad as 2000 idle and would not go below. Shortly after it fixed itself.

Recently, when dropping rpm from running to idle, it will drop all the way down to 500 and catch itself from dying. Twice it has died, first time it threw a p0420 pam position sensor code, and the second time, no code. Turned it over and it would not start. CEL and no code... reset the dtc's and everything I could, nothing. Would not start, just crank. Like either no fuel or no spark. Hooked up the jumper harness to the truck and it started up and ran after clearing the cel it threw, it threw a p0100 maf cel (I think because I switched?). Stopped and reconnected the FIC, and it ran once again. Sounded fine. AFR's are fine throughout the whole process, but sometimes at idle they'll go from 14.7 down to 13.5 and up to 15.8 and eventually go back to 14.7. Can't figure this out.

Resistor on cam signal screwing oem ecu up? (needs capacitor?) Vapor lock?(I have a 340lph pump in the truck) Cam sensor? MAF? Just the aem being finnicky after sitting too long without plugging in my laptop? (6 months since I have changed anything)

 

Guessing that’s issue is new since you installed the headers?

 

Unfortunately, I have not been able to install the headers yet as I decided to get a project (85 mr2) Was planning to put those on the truck while driving the mr2 but it blew up so the last mod to the taco is the fuel pump

 

Oh, fucking fuel pumps. Ive had my fair share of fuel pump issues.

not saying it’s your issues but it might be worth looking at. My next “mod” will be a fuel pump gauge.

I just noticed today that when my tank gets low with my OE DENSO replacement my fuel trims get wacky as shit.

I’m thinking the low head pressure is causing some issues even with new filters all around.

 

I dont think its the pump, there was plenty of fuel (3/8 tank). I am worried that i might be overheating the fuel and vapor locking... Jon thinks its the cam signal being messed up by it so I think I am going to start by disconnecting the cam tap/intercept and see where that gets me.