Another cam P0300 code issue

[5150WS6]

Hi guys,
Ok. So I've been all over the net on this. Been on the phone with the tuner, been on the phone with the mechanic and the race shop. I'm still lost.

I did a swap in my 2011 SS Camaro. It started with the L99 with the auto trans. I did the Brian Tooley stage 4 cam, Stainless headers, AFM/DOD delete and Circle D torque converter. Plus all the supporting things came with the kit from BTR.......springs, lifters and all the supporting goodies.

All was installed. Tried to start it with no tune and it was a no go. Sounded horrible and would fall on it's face. Did the tune and it's started and ran great. Stopped the motor, let it cool off(to heat cycle the springs) and went to restart and it fell on it's face again and started giving the misfire on all cylinders P0300 code.

So here's where I'm at. Tuner says it's something mechanical, mechanic and BTR say it's the tune.

I have checked the following. Cam position and points all line up there so it's not advanced or retarded or off. All spark plugs have been replaced twice and confirmed gaps. New Taylor plug wires and also tried the stock AC Delco.

The other thing it could be is the coil harness on backwards but I've checked that also and am 99% sure that's correct as well.

When it idles it also throws up a code and also the traction control lights come on as well.

The car runs great once you clear the code and get it past 2000rpm. Codes go away and it's happy. Idle though is just a disaster. Smells rich to me.

I know this is a common problem with aggressive cam swaps like this on a "normal" engine. But I've seen plenty of guys online with the same set up with no issues.

And please cut me some slack. I'm in an area with NO race shops and no support other than the phone. So I'm doing the best I can with what I have. Just because I live in Oregon doesn't mean I shouldn't have a badass sounding car

Anybody offer me some ideas here? Thanks for any input.

Mike

[morepowerjoe]

If you don't mind telling us who did your tune?

[5150WS6]

Originally Posted by morepowerjoe

If you don't mind telling us who did your tune?

Steve Leerentveld did the tune.

I am fairly confident that it’s not the tune. In fact I am 100% sure it’s not the tune. From talking to guys their cars would start without the tune. Mine wouldn’t. So I think there’s def something wrong.

I’ve tried two sets of plugs, two sets of wires, checked the coil wiring harness to make sure it’s not reversed.

Tonight it won’t even start. It’s super super rich. And just falls on it’s face.

The next possibility we are thinking is possibly the timing chain. The mechanic said that he lined the arrow up with the dot on the gear and crank gear which should be zero advance/retard. He did say that the stock chain tensioner had a spring in it that would kind of push up against the chain. But the one that BTR provided just sort of rusted close to the chain and there was more play in the chain than he thought there should be. I’m wondering if this is not causing the issue?

I have a Volair airbox on it also. It has a hose that runs between the mass airflow sensor and the filter and at one point when I first got the car I had accidentally unplugged that and got the same motor running characteristics. I’m wondering since the PVC is now internal with my AFM/DOD delete that if this is may be causing the issue as well somehow. We blocked the PCV valve breather off in the back of the valley cover. And used the new provided LS3 hose to connect the PCV to the bottom of the throttle body.

I’m seriously at a loss so any input is appreciated!

Mike

[morepowerjoe]

Did you get the intake valley cover with the pcv provision on it?

[frankwjr]

double check all the grounds...especially the one on the back of the heads...

[5150WS6]

Morepowerjoe, yes got it all as a Kit from Brian Tooley Racing. It has the PCV stuff on the underside of the valley cover. Then a cap for the vent tube in back and a new hose that went from the valley cover to the port on the passenger side of the manifold.

Frankwjr, we checked all of those twice. No broken or messed up wires and all grounds are tight.

Mike

[morepowerjoe]

Where do you have the fresh air inlet from the air intake tube going to?

[5150WS6]

We have that fresh air tube coming out of the bend in the air cleaner tube and it goes to the passenger side valve cover vent.

[morepowerjoe]

Well that's all correct then so you can check that off your list.

[5150WS6]

Yeah I just don't get it. I'm sure it's not the tune just because it wouldn't start right after we put the cam in. So it's something else I'm missing.



After the tune it started, ran good. Then started throwing the 0300. The more we tried to start it the worse it got to the point now where it won't start at all. I'm hoping it's not something like a valve or something. But the motor sounds good when it does run. I have to give it substantial throttle to get it to start and idle. And even that takes a few tries.



At this point we have checked and rechecked:


Timing. Set at 0. Points and arrows lined up. The timing chain seemed loose but talking too BTR, they said this is normal and probably not it.



Plugs. I've tried two brand new full sets of plugs that Steve recommended.

Wires. I bought brand new LS3 Taylor wires and tried those. Haven't tried stock AC Delco because my stock set had a rip in one when the mechanic pulled them off. I know one guy on the forum said he went back to AC Delco GM factory wires and that solved things for him.



Coils. We checked and rechecked to make sure they were not hooked up backwards. Mechanic just pulled the entire assembly off so he never even unplugged them other than the main harness. But they match up color wise where they are supposed to go.



Fresh air hose is good and connected right as noted above.

Nothing is missing a connection.....or there are no bare plugs that don't have a home.


Grounds are solid. Checked and rechecked them all.

Battery is good other than tired from trying to start and restart a car that doesn't want to start.



O2 sensors are all hooked up and not throwing any codes.



I'm totally at a loss and the mechanic wants it out of his shop lol. I can't blame him. The only code that shows up is the P0300 with check engine light and all the traction control lights saying it needs service there.

And when I can get it above 2000rpm all those lights go out. So to me it's almost like there's not enough spark at lower rpm or idle and getting it up in the r's gets enough spark to burn everything appropriately. And it smells rich......so to me it's something with the spark that's wrong.



The mechanics computer shows it randomly misfires on all cylinders, not just one. So would one bad plug cause a misfire with all cylinders? I don't think it would but I'm not a mechanic. To me it's more something that controls the spark for all. Which would make sense to be like a ground or something.


Ugh. So frustrated with this thing.

Thanks for any input you guys can share. I appreciate it.

Mike

[morepowerjoe]

Have you checked fuel pressure?

[5150WS6]

Morepowerjoe,
I have not checked fuel pressure. But if fuel pressure was off, wouldn't it not run above 2k rpm? The mechanic took it out this morning and said if he can double foot it and keep the idle high, the car runs great. It's just at idle.

But I don't know. If fuel pressure was off would it effect both above and below 2000rpm?


I can certainly have him check.

[morepowerjoe]

Yeah I would have checked that first thing. And I think it should be around 55psi.

[morepowerjoe]

I really don't know what else it could be.