Alchem1st

iTrader: (2)

Hey guys, I've just finished the new engine build for my car and I'm having a terrible time getting it to idle. The mod list is a little strange I know because I lost my job in the middle of the build and went from a crazy power build to a I want the car to run build lol. Here's the mod list:

Evo 8 block
Manley Forged 100mm crank
Manley TT I-beam rods
ARP main studs
Cosworth main/rod/thrust bearings
Tomei crank scraper/windage tray
BS delete
Evo 8 head gasket
Curt Brown cylinder head ported and polished
GSC SS valves
Bronze valve guides
Kiggly beehive springs with Ti retainers
Kiggly HLA regulator
stock Evo 4 cams
Curt Brown port matched intake mani with 70mm throttle body flange
Full Blown 70mm throttle body
Stock fuel rail with -6 ends
ID1700cc injectors
stock exhaust mani
stock Evo 4 turbo rebuilt with a Kinugawa rebuild kit and Kinugawa 20G compressor kit
hard pipe intercooler piping kit
JMFab intake
Squirrelly Performance 4.5in MAF adapter
stock Evo 8 intercooler (will be upgraded before power tuning)
Evo 4 wiring harness
Evo 5 Ceddymodded ECU
AEM UEGO wideband simulating the narrowband upstream o2 (note there's no downstream o2 on an Evo 4-6)


I think that's all the important bits!

Now, here's the issue. On startup the car runs pig rich (12.0AFR) and misfires all over the place. Once it warms up the fuel trim leans out to 13.9-15.5AFR and jumps anywhere in between at any given moment. It's not stable at all. The car did the same thing with 2G DSM 450cc injectors so I know it's not an issue with the ID1700's. Upon free revving to 3k-ish rpm I get 3-5 counts of knock which triggers the CEL. (part of Ceddymods) I've checked about everything. The injector scaling is set at 1552 with a deadtime multiplier of

4.69 - 4.440
7.98 - 2.808
10.03 - 1.752
12.01 - 1.272
13.99 - 0.984
15.97 - 0.816
18.68 - 0.672

To me everything looks correct. STFT is around -4 constant. LTFT is between -1 and -10 floating. Plugs are gapped to .024. I don't understand what I'm missing here. I attached a copy of the last datalog I took at idle. I'm hoping I'm missing something obvious. (Ignore the coolant temps, I was fighting an issue with my cooling fan and I've since resolved it with no improvement to the situation) Note that this was a warm start scenario so you won't see the rich condition part; but you should in the video's I took here:




Note that the day after I took the second video the car started running rich again and went back to misfiring. I figured out that the reason was because the car didn't have the chance to cool down. I know a lot about setting up these ECU's; but I know very little about actual tuning at this point. This is more or less my first rodeo when it comes to this. I'm hoping someone with a more trained eye can help me! If I'm missing info needed to solve this I can more than likely give it to you as I built the whole car. Thanks in advance!

Biggiesacks

i would start by checking for any vacuum/boost leaks. Second have you dialed in the BISS on the Throttle body / how many ICSV steps are you logging in evoscan durring idle? Third what is the min injector pulse width for that ceddy rom? You could be hitting up against that with those big *** injectors. Also from my experience its normal to see knock during free reving, so don't do it, and when your gonna launch let the rpms build up slowly (like don't stab the throttle) and then bounce off the stationary rev limiter to get a knock free launch.

Alchem1st

iTrader: (2)

I'm actually in the middle of making a boost leak tester. Hoping to have it finished tomorrow so I can test it. I would think it would be lean at idle and rich under boost though if it was a vacuum/boost leak. Only partially. I've not gotten the Speed Adj. Screw mode actuator to work properly, but I've only messed with it somewhat. I more or less just matched the target idle speed to the engine rpm and went with it. ISCV steps are at 38 at idle and don't change really at all. I wouldn't think it would be to do with the injector pulsewidth since I had the same issue with the DSM 450cc injectors; but how would I tell? I understand what deadtime is; but I don't understand how the numbers in the deadtime table correspond. Would it be the top column and see what the lowest value it will accept is?

Biggiesacks

well for your rich startup afr you probably need to adjust your cranking enrichment ipw adder table a little bit. Dunno if the idle strategy for the older rom is different but you should definitely be seeing ISCV steps changing as the engine tries to maintain idle, if they aren't then thats maybe an issue.

As for the min ipw topic it would probably be a good idea to see if anyone else has had to change that with your specific injectors on your fuel type. Its a little more complex because different roms have different min pulse widths so if you can find the right xml definition for your rom that would help alot.

Biggiesacks

Another thing, how far back is your wideband 02 sensor? If its too far back it could be a little too slow to respond to the afr swings in closed loop.

Alchem1st

iTrader: (2)

Hmm, could be. Here, I'll just post up the map and def. Should be a standard map besides the scaled injectors. The wideband sensor is in the o2 housing where the narrowband sensor was. It's set up to simulate the narrowband o2. Map and def are attached.

Biggiesacks

oh thats way too close for a wideband. Its gonna melt down right there, it needs to be further back from the turbo. On the plus side, at least thats probably not the issue.

Alchem1st

iTrader: (2)

Yeah, I know. It's mounted there for now since my 02 sensor was dead and I wanted to use the o2 simulator. Once the car is sorted out then I'll move it.

Biggiesacks

the instructions for my wideband (ZT2) called for at least 16" away from the turbo. It uses a bosch LSU wideband sensor.

Alchem1st

iTrader: (2)

Yeah, I have a bung welded onto my dp for the sensor, but I moved it up so it would give a better narrowband reading for the ecu.

Biggiesacks

i just looked over your log, and your ISCV is moving so thats good, but it does seem like your IPW is hitting against a hard 1.28 floor. That could be a problem.

Alchem1st

iTrader: (2)

That could be the issue I guess. Did you see the first video to hear what it sounds like? It's worse in person than the video shows. You can hear lots of popping from the downpipe. (No exhaust currently)

Biggiesacks

just watched the video, and thats not actually that terrible. I think it could just be a combination of some things. I noticed the intake, so im thinking you probably could benefit from rescaling your MAF, then also that min pulse width thing could be causing some troubles too, esp since you have high Z injectors. The stock ecu expecting low-z with a resistor has extra pulse width built in to deal with that. From the video i don't think your engine is miss firing so much as its just pulling timing trying to control the idle.

Alchem1st

iTrader: (2)

Hmm, now that's something I hadn't considered. I thought that since the MAF internal diameter was a constant it would read ok. Is that wrong? I'll do some research and see about trying to correct it. I'm thinking that you're probably right about it being a combination of things. Don't forget though that this car reacted the same way with the 450cc injectors as well, so I'm gonna try rescaling the MAF and see if that helps. Honestly it's the only thing I haven't messed with yet. You're correct though; in all my logs the engine is pulling timing at idle. Maybe that's all it is! Would explain why despite how the engine sounds and runs it rarely ever knocks.

Biggiesacks

Changing the intake does have an effect on the maf readings, and there is link in one of the sticky threads on how to rescale it. Down the road when you get to dialing your fuel trims in, if you find you can't get them within acceptable range you might revisit the Min IPW thing. I think overall you don't have any fundamental problems, your tune just needs some polishing. Which is pretty understandable, as you said in the video its just an off the shelf tune for breaking in the engine. All the stuff i talked about are things that a tuner would touch on once its ready for tuning.