Big Cam Start Up Tune for 2017 Jeep Grand Cherokee 6.4L Need Help
Need Help with this wk2, its kicking my butt for just a start up tune. Runs very rich off stock (modded for headers) file and wont idle so I have taken fuel out but have hit a brick wall. wont stay idling even. starts and runs for 10 secs or more at times but idles down then drops too low.
Has large cam with phase limiter installed. have locked the phasers on full advance (phaser disabled) for the time being.
I have added a log and tune file but beware, they are total garbage.
If anyone has a Tune file for a cam for this thing I would love to hear how you solved this issue and would like to study your file if you would be so kind to share.
Thank you.
First thing first, copy your VE bank 1 over to VE Bank 2, doesn't look like your disable switch is working and is why you have -20 fuel trims on bank two and near zero on bank 1.
If that doesn't solve the bank to bank difference, pop the passenger side valve cover and verify by rotating the motor over that every pushrod and rocker are moving as your turn over the motor. 20% fuel difference bank 1 to bank 2 indicates a cylinder might not be seeing full valve movement. Second, verify your 02 sensors on bank 2 are correctly installed front and rear, again something is up with fuel that different between banks.
The rest of the issue is all in the basics of a big cam tune. You need to dial back timing in your Part Throttle Spark table in all the 512, 672, 896, 1056 columns to be 14* for now, and blend them to the right from there. Right now you are commanding 25* of timing at idle which is going to cause high rpm overshoot. Once it overshoots itll close the throttle causing a dip, rinse repeat.
Once you get the bank to bank fueling figured out, you will need to dial back your VE table, somewhere in the 10-15% minimum range. But need to get any mechanical issues ruled out first before hacking up the VE table.
Found a o2 sensor bung leaking, fixed that and now fuel trims for both banks are even.
Onto the next.
I have heavily modded the idle / throttle body settings. take a look.
Its nice because the car will actually start and now, it will idle given fuel adjustments are in order. i can even turn the a/c on without it stalling.
Im going to pull the spark plugs next and swap them out due to all the rich starts.
If i had a tune for every tune that a tuner didn't want to share, Id have a tune for every tune.
Runs very rich off stock (modded for headers) file and wont idle so I have taken fuel out but have hit a brick wall. wont stay idling even. starts and runs for 10 secs or more at times but idles down then drops too low.
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If i had a tune for every tune that a tuner didn't want to share, Id have a tune for every tune.