Custom Tuning Step 2 of 4
by Michael Decipha Ponthieux
This page ONLY applies to those whom were directed here AFTER receiving a custom tune from me and have completed step 1.
Last Updated: 7-12-2016
Part Throttle Fuel and Spark
Now that step 1 is complete and low load fuel is dialed in, now is the time to dial in the isc multiplier, part throttle fuel, and spark.
Go ahead and turn the ignition key on and plug the usb cable in, before writing the updated tune to the quarterhorse adjust the throttle stop screw if instructed to.
If KAM's need to be cleared they can be cleared by doing any of the following outlined here in the Fuel Write Up - Reset KAMs
Now that the KAM's are cleared, you can go ahead and start the log BEFORE you crank the engine.
Let it sit and datalog until the engine reaches warm operating temperature, DO NOT TOUCH THE THROTTLE, let the engine reach warm operating temperature.
At this point, the engine should be at its normal operating temperature and likely has been idling for at least 10-15 minutes or so.
Idle in Drive for Automatic Electronic Controlled Transmissions (94+ only)
If you have a 94+ ecu with an electronically controlled automatic transmission, shut the engine off, wait approx 20 seconds and restart the warm engine.
Immediately put the vehicle in drive and hold the brake, include a 4 and the half minute datalog of it idling in gear.
Do not move the vehicle or take your foot off the brake. We need this to dial in the isc drive multiplier (airflow in gear)
Once that is completed, (If applicable), we can then proceed to dial in the fuel.
Remember, the engine has to reach a warm stable idle (not surging) before dialing in fuel otherwise the datalog is useless.
For the step 2 log you must drive the vehicle, but you must verify the ecu is in closed loop first
this can be observed by LAMBSE1 jumping around constantly increasing and decreasing instead of staying at one set value.
While shes warming up, I recommend checking over the tire pressure, lug nuts, etc if you hadn't already in step 1.
If the car has been sitting a while or if you hadn't put fresh fuel in the tank recently then now is the time to do so, your first trip should be to the gas station to fill up with fresh premium fuel
(low grade fuel can only be used if discussed and the tune is setup for it). Now that you have fresh fuel, Hopefully you have a nearby patch of road you and your comrades use for testing and tuning,
you know what im talkin' bout! Go ahead and cruise on out there to perform the step 2 log. If you don't have an area you play around in, you can take her out on the highway where you have a
straight patch that you can safely do some playing.
For the step 2 log lock her in gear lugging at about 20mph and start a new log, once the log starts, stab her at HALF throttle and HOLD it there until you get to your shift rpm
but don't shift, instead of shifting let go of the throttle (hit the clutch if a manual trans), let her coast back down to speed (say 35mph or so) then pull over and stop the log.
- If you have a manual trans its best to do the step 2 log in 3rd gear
- If you have an auto trans you must lock the gear by putting the shifter in 2nd, if you cannot manually place it in 2nd then 1st gear will do.
If you have a glide then do the log in 1st.
Zip the log(s) and post it, I'll shoot you back an updated tune after i review it
If you hear any detonating during this time (that unmistakable piston ring flutter sound) note the RPM and Load the engine is at and stop the pull, no need in sending a log just
email me back or call me on my mobile with the rpm and load values where it was detonating at so i can send you an updated tune
After you stop the log and unplug the usb cable shut the engine off and check for any coolant, oil, powersteering, or any other leaks underneath the car, pop the hood and make
sure nothing has come loose, just give it a good double over.
After i review the datalog, I'll post back with an updated tune so we can proceed to step 3
DO NOT forget to zip the log, if its not zipped the forum will not let you post it, so the datalog must be zipped (.zip file), you should be able
to right-click on the datalog file and click on "send to" >> "compressed (zipped) folder", then just post the file it created (which will be the .zip file),
in your Private Tune Progress Thread.
If you have any issues along the way don't hesitate to give me a shout on my mobile: five zero four six zero six zero five three two
Note: Nowhere in this step does it say anything about going WOT. DO NOT for any reason go WOT as it will probably blow the engine.
Understanding Step 2 Changes
After getting the fuel close I return some values back to a sane value.
|Hego Min Switches||I usually set it between 3 to 8 switches dependent on mods
|BYPLES||I drop it back down to 15 sec
Return to Step 1
Continue to Step 3
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