Interesting!

 

If you have an EVO maf, you should use the evo settings I believe. Lancer MAF, lancer settings.

When switching to the Evo ROM, some of the most important things to change are:

Injector scaling and timing - stock lancer if stock injector
MAF if different
ISCV but not a direct copy, they are backward in the Lancer ROM
Knock Sensor settings, although everyone seems to need to tweak them (not knock filter maps, those are wrong and unrelated to knock)
Fuel and Timing maps, Lancer uses low octane EVO rom uses high, so be aware
Idle Stepper table seems to work better if copied

Throttle hang in the 9653 is for all cars, not just lancers, so use the evo fix to resolve that

Those are just the things I can think of that aren't imediately mentioned but I had to change them some. Specifically for idle, and also the .... warm up enrichment or something, can't remember, but it helped me a lot to get that copied over. It's pulsewidth for when the car starts.

 

The evo 399 maf is just too large for my na car to handle. The 501 and stock 605 are working now. I had forgot to put the maf restrictor plates back in so the cars back up and running but not running like it should on tephra.

I figured out the maf Hz conversions so that's covered and I'm hoping with the xxxxx15 tephra Rom the little issues I'm seeing will get solved.

I got everything on your list converted for my map excluding the iscv and knock sensor stuff. Nothing from my stock rom knock maps translated to the tephra Rom from what I could see. Think you could post a pic or something of what you did in this area?

 

One thing I would like you to pay attention to is real strange idling issues with this rom, because I am starting to wonder if its the rom itself causing mine here is a video


I have tried countless fixes to remedy this with no luck. Other than this issue my car runs fantastic.

 

I'm seeing the same issue with my tephra map . I wondered if it's a tephra rom issue or an evo rom issue?

 

Mine did that in the past as well, but it no longer does. I believe it was ironed out when i put the lancer idle stepper table in, and then adjusted the BISS screw first, then tweaked the ISCV tables to get my ISCV trims at 0.

Mine also did it before I did all those fixes, and would eventually even out after about 10 minutes of idling. The way I have it now though it doesn't happen after a reflash anymore.

 

03:

Whats your vacuum gauge doing just before stumble and just after? It almost sounds like it completely shuts off like mini fuel cut.

Possible scenarios:

1) Fuel decel cut at idle caused by load going below threshold and initiating injector cut. Solved with maf scaling to boost load in affected area and ajustment of maf smoothing to boost fuel/reduce fuel as needed.

2) Idle air valve system hunting should be visible with vacuum gauge hunting around as the IAC makes adjustments then a surge up as the IAC kicks back in to save the car from shutting off.

3) Extreme lean idle condition to the point of lean missfire caused by maf smoothing most likely but possibly the rpm ve table if SD.

 

I tweaked those values until my fingertips started to bleed lol.

I just went out and went for a drive and paid close attention to these, the idle dips have nothing more than an arbitrary affect on the vacuum guage, it sits about 22 inhg at idle and it may vary by 1/2 a point, to maybe a full point if it dips really hard. I have swapped out the idle air control valve with a known good one with no change in idle condition.

This first idea is interesting and possibly the most promising, I have known that with my a/c on and the magnetic clutch engaged turning the pump the car will not dip ever. and I see in the decel fuel cut maps the neutral a/c on map has much higher values in the low load area than the other 3. Would it be a good idea to make all 4 maps the same? Or might that cause an issue?


Update:
So I went ahead and took the other 3 decel fuel cut tables and moved them about halfway between where they were and were the neutral a/c on table is at with no real change. Then I realized those tables were just delay tables so I imagine this would not have any effect anyways. It must be fuel as I checked to see if the spark was being cut but nope the plugs are firing during these dips.

The mini fuel cut is exactly what it seems like its doing. I always tell people its like I turned off the key for a split second then back on before the engine could completely die.

 

I see the same issue on my car with the tephra Rom on stock 605 and 501 mafs. And it does go away with the ac on.

 

If you believe its decel fuel cut caused by the engine load going below the threshold, which i've personally experimented with in an evo. The easiest thing to do is artificially up the load.

If your SD you do this by simply increasing the load via the boost to load table which will cause you to run a bit rich. To compensate this you adjust the maf smoothing table which is still in effect to lower the fuel back down to normal levels.

In a maf world you would increase the value at idle HZ range so the load is above threshold, an evo is like 25-30 load minimum btw, and do the same thing with the smoothing table to lower the fuel back to acceptable levels.

 

Seems like when my idle is stable its hitting 26hz. so just to confirm I want to raise the values in that range in the maf scaling then also raise the value in the smoothing table. I believe the smoothing table in my rom is called the compensation table but I will double check that.

 

If you raise the load you'll need to lower the value in the smoothing/compensation table to reduce fuel. Remember load is like a master fueling table more load means more fuel.

 

Made some adjustments as indicated, so far no change :-/. debating taking my biss completely out to clean in there to see if that helps. Shouldn't be an issue to get it reset.

 

biss?

 

Base Idle Set Screw, there is a small rubber plug on top of the TB next to the firewall. Under it there is a screw, I have thoroughly cleaned my TB multiple times but I never have pulled that screw all the way out and checked for possible gunk build up under it. At this point that is one of the few things I have not cleaned, swapped, or adjusted. trying to get these dips under control.