Cam Swap

[Jlinhardt]

2011 Auto Camaro (L99) SS 6.2l V8
Prior to Cam swap: straight piped and aftermarket air intake that is all
Developed a lifter tick in cylinder 7
Decided to do a AFM/DOD delete and because of cam selection did the VVT delete as well. Built it with my buddy who has built race motors for years, so mechanically it is sound. He is old school so no computer knowledge, I took it to a local tuner who was known for HP LS tuning. He has turned off DOD and VVT. But while there, he added octane booster and it started missing very bad. I have done a few things since to try and help clear up the missing, new crank sensor, new knock sensors, kit came with a new cam sensor, and new O2 sensors. I was wondering if anyone has seen this or knows if it is in the tuning.
I ran the O2 relearn and crankshaft relearn and idle relearn. Seems mostly missing in bank 2 and even further cylinder 8 more than any other in bank 2. Is there something I am missing? Or is it in the tuning? I do not have the logs yet as he is racing this week and will not be back until Monday.

Specs:
TSP Honey Badger Cam
"Honey Badger" N/A LS3 218/230 .600"/.600"; 115+3 LSA

[morepowerjoe]

Did he hurt the engine? I would check my plugs if I were you.

[GHuggins]

While you're at it and since it doesn't take that much more time at all to do it, you might want to go ahead and yank the valve covers and do a quick check of the worst cylinders misfiring. If you're lucky it just knocked the ground straps off the plugs, but could possibly be something mechanical. That cam shouldn't have kissed the valves if it was pushed to 7000, but if pushrods weren't upgraded it is possible some bent or warped...

[TheMechanic]

Maybe a compression test and or a leakdown test.

[Alvin]

Nothing in the tune can make it miss on just a cylinder or two. I'm sure you've pulled plugs at this point?

[Pitbull]

Feels like there is something in the details missing..... I've use gallons upon gallons of octane boost in my 6.2 denali, never missed....

[TheMechanic]

My initial thought was as others I think did, is that it was rattling to beat the band and after the damage THEN it was decided "hmmm. Tell him it needs octane booster then blame the customer if it comes back".

[Jlinhardt]

I have pulled one set of plugs. Will pull the second set tonight after work. The thing that gets me is that anything I do will clear it up for a test run or a day but then I go to take it out again it starts missing all over again. And I do not think the octane booster really did anything other than clog the O2 sensors the rest of the way. I mean they were due to be changed either way.

[gtstorey]

Sounds to me like you need to be looking at some data logs.

[GHuggins]

^^^^ Yes, find out if it's too rich, injector sticking, clogged cats due to melting or anything like that. The way you initially wrote it out sounded like a dead miss. Didn't know it was coming and going. Make sure all your grounds are good and tight too.

[Alvin]

I have pulled one set of plugs. Will pull the second set tonight after work. The thing that gets me is that anything I do will clear it up for a test run or a day but then I go to take it out again it starts missing all over again. And I do not think the octane booster really did anything other than clog the O2 sensors the rest of the way. I mean they were due to be changed either way.

I've seen injectors miss on occasion and then stop like nothing was ever wrong.

Seen the same with wiped cam lobes.

[Tfoggy]

You didn't state if which pushrods and valvesprings you used when you installed the cam...
That would be useful . Hope you didn't use stock stuff.. also your rocker arms should have been upgraded with
a 600 lift cam (trunnion update). Check your rockers too. Hopefully you used the correct length pushrods too

[Jlinhardt]

So did some checking last night and I think the tuner never changed the idle, so on stock idle settings it is missing but anything over 1000 or 1100 rpm not a single one. With a new cam of course the idle needs to change. I know I will have some misfires when you let off a hard pull but I will see what he says Monday or Tuesday when I take it in. I will double check the rockers but as for pushrod length I bought this all together in a kit so that it would line up. Take out the guess work. And I still want to drive it on the road, but next time I?m that deep in it I will probably go the full 9.. just hoping it?s not for awhile. Lol pushrods and valve springs were PAC/TSP dual springs 660 and I think 7.400? I can double check. Starters watching the HP Tuner reels and some people on YouTube. Trying to see if anyone had this issue and the closest thing was idle speed and one person half described this issue so ill post again after talking to tuner.

[Jlinhardt]

I have been asking for them and he just shows me in person. Which is the frustrating part of it. I?m pretty good with computers as that is my day job.

[Jlinhardt]

My scanner allows me to individually test each injector and psi were all identical except 1 which was psi off. 27psi after Ecm triggered it and I think 5 or 6 was 28psi.

[gtstorey]

I think the pushrod length that comes in the kits are "usually" ok, but it isn't 100%

[Jlinhardt]

I called about that and emailed both the kit provider and TSP. Both confirmed. As this is my first non-diesel motor rebuild I was worried about it and when we got the kit we measured and it was exactly what was needed I just do not remember the length. Big thing left I want to check is rocker arms. And see if I can adjust rpms. I think I can but I can?t adjust it permanently. Thanks all for the input has been extremely helpful. I?ll probably look into tuning it myself later at least so I better understand what the tuner did. I do not like not knowing what he has done.

[Tfoggy]

The pushrod length should always be dialed in anytime you change components.. But yes, the 7.4 is the normal so you should be ok.
And the springs are good too.. Just didn't mention those in post originally . So you are ok there.

[Alvin]

We sell and install cam kits. They all go out with 7.400's but two of exact same engines with the exact same grind from comp will end up with different pushrod lenghts. Every one we build gets checked. It really must be done and it isn't hard at all to do.


It's got to be checked.. but having that off usually just means you'll wear the cam out sooner or it will be more tappy than normal.

[pannetron]

Make sure the ground wires from the wiring harness were securely bolted to the rear of each cylinder head.