Schnitz

Started my car 6.0 (LQ4) with the EFI Source Gold Box.
Wouldn't run ( turns over but doesn't catch) so I called up EFI Source. They checked the diagnostics with me and determined my cam is 180 degrees out.
Pulled of the timing cover and gears are dot to dot but not at TDC (compression stroke) on cylinder 1.
I thought I installed it at TDC on #1 but I must not have.
I have searched and read lots of threads but some say it's impossible to install a cam 180 out on these motors and some say otherwise.
I just want to know how to fix the issue and get her running.
Any concrete advice is much appreciated.
Can anyone suggest how I fix this?

G Atsma

Is the cam dot on the BOTTOM of the cam sprocket and the crank dot on the TOP of the crank sprocket?

Schnitz

It is still that way when I took the timing cover off. I rechecked to see if it was also at TDC but it's not.

Michael Yount

iTrader: (1)

79LS1FOX

iTrader: (11)

It is possible to install 180 out cyl 1 and 6 would both be dot to dot but 6 would be TDC on the exhaust stroke....

Michael Yount

iTrader: (1)

01CamaroSSTx

iTrader: (3)

If it's installed correctly which is the No.1 cylinder at TDC on the compression stroke. The dot on the crank sprocket will be at 12:00 and the one on the cam gear will be at 6:00. The dowel pin on the three bolt cam will be somewhere around 2:00.

Michael Yount

iTrader: (1)

There is no "Compression Stroke" UNTIL the cam is installed correctly. C'mon guys. Knowing where TDC on the compression stroke is is what's necessary for setting IGNITION timing correctly. Ignition timing and cam timing have virtually nothing to do with each other. Degree the cam with someone that knows what they're doing -- you'll learn a TON about how all these pieces work together.

01CamaroSSTx

iTrader: (3)

I just helped some guys out of Oklahoma out who I'd ran into at O'Riley's last week. He was in town helping out a friend with a cam swap and tune but had left some of his tools behind so I offered up mine and my time to help get the cam swapped over. The BTR kit he purchased had a three bolt cam and sprocket and the one in the car was a one bolt. I made sure before we pulled the cam that we where dot to dot or 6-12 with the No.1 on the compression stroke. It's a bit tricky getting the new cam sprocket positioned on the timing chain so everything lines up right but I managed to get in on the second attempt. After that they linked up with their tuner and it was off to make some pulls.

01CamaroSSTx

iTrader: (3)

dot to dot or 6-12 on the LS engine is No.1 TDC compression stroke!

93hatch

iTrader: (9)

if it's an adjustable timing gear you can do it wrong

01CamaroSSTx

iTrader: (3)

Every cylinder has a compression stroke! When the piston comes down its drawing in air/fuel and when it comes back up "The Compression Stroke" the spark plug ignites the compressed air&fuel causing an explosion sending the piston back down as the piston is coming down the exhaust valve is opening and is then starting to close as it comes back up pushing the spent gases and then backs down repeating the process but if the cam is installed incorrectly and valves are opening at the wrong time you will lose compression on the compression stroke.

01CamaroSSTx

iTrader: (3)

Just remember to pay attention to the valve events as both the intake and the exhaust valves will be closed meaning both rocker arms are up and not opening any of the valves with the piston is a TDC on the compression stroke.

Michael Yount

iTrader: (1)

01CamaroSSTx

iTrader: (3)

I don't disagree with you as I have a degree wheel but the cam can be installed correctly if he will make sure the crank gear dot is at 12:00 when the No.1 is at TDC and the cam gear is at 6:00 also known as dot to dot! He could probably tell if he's 180 out by simply turning the engine over by hand watching for piston travel and the valve events.

01CamaroSSTx

iTrader: (3)

He already knows he's 180 out.

Michael Yount

iTrader: (1)

jlangley

iTrader: (8)

If the cam dot is at 6o'clock and the crank dot is at 12 o'clock it is correct. Only exception would be if an adjustable timing set is being installed.

Whether the engine is at compression/ignition or exhaust/intake at tdc is determined by the cam, the pistons are in the same place either way. The ignition timing could be off by 180 degrees though.
Cam sensor problem of some kind perhaps?

fieroguru

iTrader: (1)

What timing gear set are you running? Stock setups only have a single set of dots (1 dot on crank gear, 1 on cam gear) and can't be installed incorrectly if both dots are at 12 (crank) and 6 (cam). Aftermarket timing sets can have multiple marks on the lower timing sprocket to advance/retard the cam, maybe you used the wrong keyway/tooth marks and now don't have proper valve events.

What timing cover are you running?
Reason I ask is the LS4 (FWD) version moved the placement of the cam sensor 180 degrees out, so you can run into issues like this using LS4 calibrations on RWD engines, RWD calibrations on LS4 engines, and when you accidentally swap the timing covers between the two.

G Atsma

^^^^^^This^^^^^^^ If crank and cam dots are "looking at each other", no way is the cam 180 off. Only one way those sprockets fit their respective shafts.