OK. So I did my engine install this weekend. I have several issues, which could just be electrical.
2002 LS1/6 Car specs are in my signature

1) Of course the first thing I watched when I started it was oil pressure. Brand new oil pump was installed. Idle at 20 psi but will drop suddenly to 0. If you rev the motor it will go up to 50 psi but quickly fall back to 20 psi. If you put it in gear and hit the gas it drops to 0 psi. Running 5w30 Mobil 1 synthetic
Yes, new cam bearings were installed, I was careful installing the pickup tube as well. Before the build it was at 50 psi at idle and would go up to 80 psi when throttle was applied.


2) My tach is not working at all. So how does the pcm know what rpm the engine is running? Normally on a relearn the idle would fluctuate a lot until the pcm learned the new fuel trims, etc….This thing started and idles great.

3) A few codes. A couple of tranny solenoid codes.

P0334 Cam position sensor High Voltage. This is causing my hard to start condition I’m sure. I did use loctite on the bolts for the cam retainer and gear and this is the first time it has been turned over.

4) I have a plug on the driver’s side along the fuel rail that has nothing to plug into. There’s literally nothing left to plug it into. I have no idea what it’s for. Not the one for the evap solenoid but behind it on the harness. I’ve looked for hours trying to find out what it connects to but no luck so far.

5) Also, I noticed a pink wire with a black stripe in the harness from the tranny (I did repin the pcm last year for the 4L80e swap) that is not connected to anything. But I can’t find the other end of it.

6) This has the worst piston slap I’ve ever heard. Couldn’t let it run long enough to warm up but the slap was starting to lessen the more it ran.
Any idea of where to start? Ground issue?

 

Nobody has any idea?

 

It's a Monday before holiday. Not a lot going on on the forums but let me try and give you a hand.

1.) Did you install a new Oil Pressure Sending Unit? It's very easy to damage them when doing engine swaps. You may want to swap one in and see what oil pressure is then. If it does not get better or reads the same as whats going on now then you got a problem. Do not run the motor is you believe you have a no psi condition your going to kill the bearings if you haven't already. Again, hopefully its just a bad OPSU, if not you'll need to tear into the motor and see whats going on.

2.) When you say the tach is not working do you mean it doesn't move from 0 or it's all over the place, or what exactly? This also relates to your number 3 question. The Tach is run by the pcm which see's the crank and cam sensor outputs and deduces rpm based on these two sensors. Since your cam sensor is tripping a DTC this will be a factor in the tach not "working".

3.) As said, something is wrong with the sensor potentially or the wiring. Not much more help I can give on that.

4.) Get a pic? We can help figure it out if we know what it looks likes.

5.) Never done a 4l80 swap and not sure what wires coloring or for what. Someone else will have to chime in.

6.) Piston slap is a hit or miss on these cars. Different oil weights help some. Are you sure it's a piston slap and not a rod knocking? That would explain your oil pressure also if it was the case though for you I hope not.

Hopefully someone with wiring knowledge can give you some pointers.

 

I'm sure it's piston slap. It gets better as the engine warms up. Yesterday the piston slap was barely noticeable.

The tach will not move off 0. It did move to 1k rpm's yesterday for a second and then dropped back down to 0 after messing with the harness in the back of the motor.

Oil pressure never dropped below 20 psi on the gauge yesterday and will go to 40 psi with a little throttle. I'm going to upload a video of the engine running and a picture of the connector that is not plugged in.

I have the locations of where the grounds are located.

I'm trying to find my schematic for the tranny harness I had to wire in but so far, no luck.

What I did find yesterday was the balancer wasn't completely seated and had a slight wobble to it. So I seated the balancer and where I had to splice into the pcm wiring for the nitrous there were some bad splices from moving the harness around for the last 4 months.

Both sensors (cam position sensor and oil pressure sensor have been sitting out for 4 months in the garage. Anything could happen.

Now I have to find out about the tranny codes too.

 

Engine startup

 

Resolution is small but it looks like the connector that plugs into the evap solenoid.
Three main grounding rings that hook to the back of the head on the driver side. Two on one bolt and one on another typically but order won't matter. Another grounding strap is at the back of the engine on the passenger side that runs to the body and screws in, same for another on the driver side.

But it sounds like the wiring for the tach is loose or off if it jumped for a moment while you were wiggling the harness. Might have to break out a voltmeter and track down the pins. Auto stores will have manuals that include the wiring diagrams for your model. Or I'm sure it's posted around here online somewhere.

 

I have no grounding strap on either head going to the chassis. I do have the three straps from the harness on the d/s head but all three on the same bolt. I have a grounding strap on the front d/s head going to the chassis though. Could that be my issue?

 

I was able to get a good look at the pic without the preview and zoom in. I think I have the answer for why your tach isn't working :p Also I can see your Evap is plugged in.

That's your cam sensor connector. It's the only thing back there that has a plug like that. Other than the map and the OPSU, but your getting a reading on the dash for oil pressure and you'd throw a map DTC if it was unplugged so I can only imagine it being your cam sensor connector.

It would explain your DTC also with it being unplugged.
Get that connected and it should solve a lot of your issues.
As long as the three main grounds are on the back of the head your fine. The two hooked to the chassis aren't necessary and may only be a 98 specific thing.

 

It won't reach back there and the cam sensor has a connector on it now. Maybe it's the wrong connector but there is one on it.

 

So I started pulling the motor yesterday. After I pulled the intake I started disconnecting the OPSU connector and the OPSU turned. I could literally turn it by hand. I turned it 10 times before I could no longer turn it by hand. I didn't tighten the sensor a buddy of mine that was helping me install the motor said he tightened it, which obviously he didn't.

I don't know if that could give the gauge a false reading or not. I guess I'll have to put the intake back on and turn it over and see if that fixes the low oil pressure reading.

 

Prob not tight enough to make a ground connection through the oil/sealer/tape.

 

Pulling the motor and tearing it back down just to make sure. Way too much time and money invested in this motor / car. I'm really thinking cam bearings. The machine shop installed the cam bearings so who knows what happened while it was there.