First time tuner need help

[CJstein]

I found a 99 5.7 Vortec for my CJ5/7 and finally got it running, but there's a knock on the driver side. I can't read the tune on the ECU because I ordered it from a guy in New York, so I'm wondering if it's possible to adjust timing and see if that gets rid of the knock, or if I need to try and flash it and write a new tune. I've attached the scan log. Thanks in advance Manoly's Jeep after getting it started.hpl

[Ben Charles]

You won’t be able to adjust the tune until it’s unlocked (sounds like he locked you out of the program)

[CJstein]

That's what I was afraid of. I have another ECU for a 99 5.7l vortec, but it has a stock tune for an Astro Van. I'm sure it'll work fine, but I'm not running EGR, EVAP, rear O2's and my gears, tire size, etc are all different. Other than disabling the DTCs for those codes, adjusting the Tire size/gear ratio etc. Is there anything else I need to check or adjust or will the rest work fine? I've attached the tune log after adjusting the axle gear ratio, tire size, and disabling the EVAP DTCs. Junkyard ECU for 5.7L DP# 122598 after tuning.hpt

[2xLS1]

I don't think HPT can lock the 98-99 Black Box PCMs. I know Tunercat can't. Not sure what else is out there to use on them that could lock them.

[CJstein]

Thanks Ben and 2xLS1. I let the engine run for 30 minutes today, for the first time since finishing the rebuild, and it ran great. The only problem was the damn knock on the driver's side. I've attached the a video of the knock. I did notice the STFT for Bank 1 was 10% and didn't go lower than 7%, but the LTFT was 25% and that's after the engine ran for a while. Is that normal? Does anyone see anything on the scan that would explain the knock? If not, I'll have to take the driver's side head off and check everything.

[Tunercharged]

I’d guess loose rocker.

[Alvin]

That's not spark knock or anything that can be helped with tuning.

Something is up with the engine.

[CJstein]

I’d guess loose rocker.

After it ran, I took off the valve cover and the #1 intake and #3 exhaust rockers seemed loose on that side, but I assumed it was because of the point in the rotation. Should I give them another quarter turn and see if that helps?

[blindsquirrel]

'Keep turning the thing until it stops making noise' is not how you adjust rocker arms.

[CJstein]

I understand that, seeing as the rest of the rocker arms I installed seem to be tight enough and aren't making any noise. Isn't it possible though, that I misread the play in the push rod when I checked the valve lash? Or is it possible when I was tightening them, I didn't turn the crank enough when I moved to those cylinders and they need to be rechecked? I've stayed off forums for a while because some like to simply point out what a person is doing is wrong, but won't offer any advice on how it should be done. I'm a helicopter mech. I've never done rocker arms, or a full rebuild before so I'm learning as I go. Thanks for pointing out that that's not the way to do it. I'll watch the video I used again and see if there's anything I missed.

[blindsquirrel]

Set all to zero lash, then add... whatever amount of preload is appropriate. Rule of thumb I tend towards 1/4 turn past zero, but different lifters may like more.

Remove spark plugs. Turn crank until #1 intake has just closed, adjust the #1 exhaust to zero. Turn crank until #1 exhaust is just beginning to open, then adjust #1 intake to zero. Do not bother with firing order bullshit like you might see posted, with multiple valves to adjust all at once then turn crank 90*... just do each one in order from front to back on one side, then do front to back on the other side.

Finding zero lash is not difficult. Back off all the adjusters one or two turns before starting. Grab the rocker with your thumb on top, 1st/2nd fingers on either side of the pushrod. Move the pushrod end of the rocker up and down while tightening the nut. You can't rely on things like spinning the pushrod, lots of engines you can easily spin the pushrod even way past zero lash.

[CJstein]

Set all to zero lash, then add... whatever amount of preload is appropriate. Rule of thumb I tend towards 1/4 turn past zero, but different lifters may like more.

Remove spark plugs. Turn crank until #1 intake has just closed, adjust the #1 exhaust to zero. Turn crank until #1 exhaust is just beginning to open, then adjust #1 intake to zero. Do not bother with firing order bullshit like you might see posted, with multiple valves to adjust all at once then turn crank 90*... just do each one in order from front to back on one side, then do front to back on the other side.

Finding zero lash is not difficult. Back off all the adjusters one or two turns before starting. Grab the rocker with your thumb on top, 1st/2nd fingers on either side of the pushrod. Move the pushrod end of the rocker up and down while tightening the nut. You can't rely on things like spinning the pushrod, lots of engines you can easily spin the pushrod even way past zero lash.

Awesome. Thank you so much. I'll try it that way tonight and hopefully say goodbye to the knock.