Varying Afr's On Dyno

[paulr33]

what ecu?

have you checked the afm?

you mentioned datalogit - have u got any logs?

[jarrod83]

i gave the afm a clean a while back it looked fine, yeh i have heaps of logs with the afr's on the logs aswell

[jarrod83]

oh and the ecu is a power fc pro

[jeffworld2]

coul dbe simply the way you are using the wideband... i'm assuming right down at the tailpipe? if so make certain you have no exhaust leaks etc. and if it is a stupidly big exhaust you may have accuracy issues anyway.

make sure its calibrated properly too

[Sydneykid]

My method;

Turn ther map trace on the Datalogit on the Injection screen

Watch closely what load cells are being used around the time of the A/F ratio issues

Check the consistency of the values, I have found the odd rouge single cell that isn't obvious until you look at that one cell specifically

You can do the same with the logging, but I find it quicker on the dyno to simply watch what's going on on the screen.

Cheers

Gary

[jarrod83]

im using the wideband in the stock 02 sensor bung in the dump pipe n it also simulates the narrowband 02 for the ecu.. it pretty mcuh has to be recalibrated everytime i turn the car the car on since it loses calibration every time i turn the car off n just outputs 7.4 over n over.. which can be very frustrating when trying new things..

sydneykid: im a little unclear what you mean, pretty much i log the afr's using datalogit which is plotted N(revvs) Vs P(load) the cells that consitantly play up and differ between the max n mins are the cells that the map tracer follows when the car is coming on boost

i was thinking maybe the 02 sensor is not giving the most accurate readings since its outputting data instantly rather than a avg over a 1/12 sec period... everytime i change it to avg it out it needs to be recalibrated n every time i recalibrate it, it goes back to instant response..

ill add some of the different logged runs when i get the laptop online

[jarrod83]

not sure exactly how to attach this, hopefully it works its a zipped data file of the .dats and .txts files of a number of runs

any help or suggestions would be greatly appreciated as im stumped..

Cheers

Jarrod

loggeddata.zip

[Sydneykid]

There is some knock there.

Have a look at the consistency of your ignition timing around 10/13 and 10/14, there are some anomalies

Have a look at the consistency of your injection around 12/14, there are some anomalies there as well.

Does it misfire when it knocks?

Cheers

Gary

[jarrod83]

have had a fair bit of knockin but never heard it misfire, i had my own tune i done myself from scratch n had the varying afr issue making it hard to tune past 12psi... then i took it to a performance shop n they started from scratch and got it upto 9 psi and said it has a fuel issue.. they wouldnt change any settings n every run the afr line would be completely different.. and their map is a hell of alot richer n retarded than mine n still has the same sort of problems at the same spots.. i can upload both maps if you would like?

[jarrod83]

okai here are my 2 maps i run not sure why the cypher one is bigger.. but its the shop one n the afrrun7 is my latest map that runs really rich in the top end n still manages to lean out sometimes

mymaps.zip

[jarrod83]

so has anyone else got any other ideas that could cause the afr's to vary so much? could it be the standard coil packs or the iriway7's im running?

[heavytrevy]

so has anyone else got any other ideas that could cause the afr's to vary so much? could it be the standard coil packs or the iriway7's im running?

U need to check things that affect AFR's (fuel and AIR)

Im guessin if ur fuel pressure is ok it must be a vac or boost leak somewhere.

Regards

Trev