intenseapple

Background on the car: Newly built motor, 8.6:1 comp supertechs, eagle rods, etc etc. LS Coils running wasted spark -- coils are D581's, can't find a ton of info other than that they are similar to the D585's so I am running them with the same settings as D585s. Plugs are gapped at 0.038ish, pulling to double check tomorrow. Not extremely familiar with tuning, but wanted to get the car running well enough to take it to a tuner and get a full flex fuel tune as soon as my MS3PnP comes in, I am currently running an MS2PnP.

So to the issue: the car has been taken out a couple times for autotune and VE analyzer. VE table seems somewhat acceptable now. I am having issues with what seems to be a very bad intermittent misfire under load, typically around 2000 or 4000 RPM, but it varies. It could also be an issue with my accel enrich acting up as I just switch to ID1050x's and have yet to get that perfected. Another note is that I am currently using the spark map I had from my stock motor with higher compression as I figured it would be safer to keep timing lower than is ideal. Here is a log of it happening:



The accel enrich jumps around, which could be a result of the misfires causing my foot to bounce slightly and change the TPS ever so slightly, I will be trying to smooth that out tomorrow as well as check spark plugs for any glaring signs of misfires. Where else should I look at to troubleshoot the misfire? I've attached a .mlg and my .msq file, feel free to tear into all the other aspects of my tune that are terrible as well.

90LowNSlo

I did some googling for the hell of it and possibly found the correct dwell setting.

https://forums.holley.com/showthread...ils-Dwell-Time

I dont know enough to be of any real help though I'm afraid...

intenseapple

Thanks! Those dwell numbers are very similar to the other LS truck coils, but I did adjust my battery voltage correction a little to better fit in that 3.4-4.5 window.

intenseapple

Update: After fiddling with the Accel Enrich settings, the problem seems to have gone away. I believe I was dumping way too much fuel on accel and pulling too much on decel. Now my issue seems to lie only above 4000 RPM when under load. The car is still misfiring? above that RPM. I'm assuming its an issue with my spark table but I have neither knowledge nor guts to start making big changes there. I checked my sparkplugs and did an oil change and all seems well in those respects. Attaching my new tune and a long datalog from a 40 minute trip that was largely highway, any advice is appreciated!

intenseapple

Another update: Just checked the oil and it is VERY low even though I just changed the oil before my trip. I went from just below the "full" mark to right at the "empty" mark in a sub-45 minute drive. I haven't noticed a ton of smoke yet but it must be burning because there aren't any leaks underneath the car. Initial thoughts are: turbo oil seals gone bad from sitting, PCV valve is bad despite being a relatively new unit from a 323GTX, valve seals are bad, or pistons rings aren't seated right or are stuck. I'd really hope that it isn't either of the latter as I had the bottom end and head built by a reputable engine builder in my area and both have less than 150 miles on them total. What's the best way to go about trying to identify where I'm losing oil?

Wingman703

Leak down and wet/dry compression tests.

Fireindc

iTrader: (13)

What trigger setup are you running? I had a misfire on my 36-2 setup, but changing from rising edge to falling edge (or vice versa, I can't remember) fixed it. You do have to re-set base timing if you change this setting.