im running out of patience and money

[Ken84ls5.3]

ok I have a 2000 5.3 598/601 cam cai headers total rebuild bored 30mm stock heads 861 stronger springers valve job 1n stock tune it was running lean bank 2 25% at idle but normal under acceleration small backfire and stalling so I did a new intake gasket felpro new intake bolts with new rubbers new o2 sensors 8 new injectors and smoked it for 15 mins with no leaks showing (tune is on here under my name) I did a non maf tune off youtube and that helped bring Bank 2 lean to 9.5 but truck had no throttle response extended crank time and constant surge at idle 2: so downloaded stock tune again but bank 2 dropped to 9.5 lean and still is after stock tune so I can drive it now and did a log and it runs but has a small backfire and will not return to a stable idle cuts off it has power under acceleration and seems ok but not 100% vacuum gauge installed showing 10lbs at idle and(reads in red late timing vacuum leak or heat riser) I tripled checked for vacuum leaks and had engine 1 cylinder TDC PISTON UP dots lined up bottom of cam gear dot to top of crank gear dot 6-12 oclock tripled checked that during installation so im 99% sure that is ok can someone read this tune and let me know your opinion im beginning to think maybe pushrod length is wrong not letting valves close all the way I measured. with a adjustable push rod length checker I got stock length going by the method on almost every site about how to measure. ive had 30 yrs experience with sbc but this gen 3 is kicking my butt badly

[Ken84ls5.3]

I forgot to send log file its long didn't wont to crank for a WHILE

[5FDP]

MAF dtc's must be set to MIL on first error and the Code P0103 needs to be present to make sure you are in speed density. Also log the MAF sensor status to make sure it says failed and then you know you are running in speed density off the VE table only.

You must buy a wideband if you want any hope in getting the fueling correct. Verify you have proper fuel pressure of 58psi too.

You can't go off of what the fuel trims say because the computer isn't using them, not the long terms anyway. The log shows that the computer is in open loop and it will not use the long term fuel trims unless the computer is in closed loop. Your tune file shows that only the short term fuel trim is active for open loop. To add to the speed density part, you still have to change the master LTFT enable to disable and disable the STFT if you wanted to calibrate this in open loop.

The open loop EQ ratio should not be 1.00 for every cell. Go back to stock on that table and only have it request 1.00 (stoich) above 130-140 degrees.

The cylinder volume is still for a stock 5.3 engine size. If you bored the engine 30 over, you should update that number so it's correct.

Cat over temp needs to be disabled because you removed the cats and rear o2 sensors. Abuse mode needs to be disabled because are working with a swap and a non factory transmission. Return the transmission type back to factory too and just disable all related codes, torque mngt for the transmission. Messing with that drop down can be harm behind the scenes when not working with the segment swap tool.

If you aren't running a flex fuel sensor, disable the flex fuel feature in the tune as well. That can mess you up if it changes fueling on you for no reason.


I'm sure there is other stuff you can change too but you're going to be on struggle street without a wideband o2 sensor and more data in your logs. Several things like knock retard, you injector pulse width for both banks, commanded AFR, cylinder airmass are all missing and you kinda want to see that stuff.

[Ken84ls5.3]

I have a innovate wideband running but not hooked up to the mvpi2 trying to figure that out also to use egr signal don't have the pro so im going to have to add wideband channel another way it reads 17-20 during idle and open throttle it runs 14ish I just added injectors to chart to read that on next scan on my snap on scanner the injectors read normal 3-5 on both banks I took off valve cover today to make sure I have correct pushrod length so when back together ill do what you said and give it a go thanks for your advice