mx594m

iTrader: (1)

car 94
block NB1,
head NB2 [VVT]
CAS, NB1 crank wheel/sensor, NB2 VVT can sensor
LS2 coils
DIY MS-PNP [1e], DIY VCM

car starts, idles rough, stumbles/bogs when accelerator pedal is depressed

what group of settings control that? and what adjustments are suggested to eliminate the stumble

thanks for any input

Joe Perez

iTrader: (8)

Not sure which O2 sensor you're using, but the AFR seems quite rich.

The temp readings are interesting. I assume that this was a fully heatsoaked hot restart? MAT in particular ranges from 140-150, which seems high.

Have you verified that the ignition timing is correct, by locking it at 10 at the MS and viewing the pulley with a timing gun?

mx594m

iTrader: (1)

the O2 sensor is the AEM wideband, and configuration is set for AEM
yes, AFRs are rich, to the point of spewing condensation and soot on startup
yes, this was a warm restart
yes, have verified TDC with round point screw driver in spark plug hole
and verified 10* base timing in fixed timing mode
also verified latency to 4000 rpm

I am assuming you can determine MAP, advance, and rpm from datalog, if not can provide

what you cannot see I am sure is the required fuel setting [6.6 for this datalog] and injectors Delphi 525, EV-6s, running nominal NA fuel pressure

mx594m

iTrader: (1)

btw, ot

read with great interest your leading dialog on spark advance
great contribution, very thought provoking
made me want to create a spreadsheet calculating spark advance to reach max cylinder pressure 15* ATDC for each rpm -- but that's a different thread

and

Joe Perez

iTrader: (8)

Ok, well, you've got your answer then. You need to tune your fueling. (FWIW, spewing condensation on startup is not highly abnormal, within reason.)

If it's uniformly rich across the board, then start by decreasing the Req_Fuel value a little at a time until it's close to stoich, and then use VEAutotuneLive to fine-tune the VE table.


Also, I notice that gEGO (AFR-based fuel correction) is just sitting at 100 the whole time, meaning that the engine is running in open-loop mode. You'll want to figure out why that is and get it running closed loop with some reasonable AFR targets.



Yeah, take that thread with a grain of salt. It turns out that my pulley had slipped badly, so my base timing was way off.

I should probably stick a note to that effect in the thread, but I'm waiting to see if anybody blows up their engine by trying to copy the maps I posted there.