Driver's header is cold
 

I've just noticed this. Pass header is lightning hot-as it should be, & driver's is luke-warm after running.
From initial start-up a few months ago, it ran rich. This might have been extra fuel from driver's side. Also, on start-up, there was some backfire/didn't know which side.
Just had a tune by Frost, and it's still rich/driver's header is cool.
The only codes are for evap.
A noid light shows spark at cylinders on driver's bank. There is some combustion at driver's as exhaust is slightly warm.
I'm wondering if swapping the O2 sensors might be a good starting point?
Any suggestions are appreciated.

checked spark plugs...there is no evidence of combustion on driver's side.
There may be a missing ground. I'll be checking wiring diagrams to see what to check next.

Sounds like the ignition coils. Make sure to check all of the grounds.

Did you plug in the EVAP purge solenoid sensor?

Fuse?

I removed the EVAP stuff.
There are two common leads to this bank in the wiring diagram. One is the GRND (trigger) control shared by the coils & the injs, & the other is the operational GRND for coils to the rear of the left head.
I'm hoping that the fix is this simple.

Is it the car in your sig? Did you just get it together? Has it ever run right? Have you done the basic checks? Compression, check for injector pulse? You said it had spark, but that's only part of the equation.

Does it backfire at all? That's a good sign that you have injector pulse, and spark on that side, and it would probably mean the coils are wired wrong. Seen that a few times on DIY builds.

The engine was started first in Jan.
It is the car in my sig. A noid light tested the driver's bank positive. I need to revisit & check for spark. Compression & leak-down are good.
There are 1 or 2 immediate backfires through header on startup, and also at low rpm/lean. I can't say through which side/both sides backfire exits.
The harness was modified by a sponsor. In comparing the factory wiring diag to the new/modded fuse setup, there is now only one fuse for injs & coils (instead of the factory-1 fuse for driver's & 1 fuse for pass).
If no spark, it could be that the batt for coil was never reconnect to the fuse. Or, maybe the comm grnd wasn't jumpered to the block.
I don't see how the inj wiring could be wired incorrectly. All of those plugs line up directly with each cylinder, and the wiring should not have been altered.
I will verify everything, and I do thank you all for the ideas.
Glenn

I didn't say the injectors were wired wrong. I said the coils. I've seen them wired wrong for whatever reason. Just a thought.

Sorry, I knew you meant the coils. I'll check them.
Thanks!

edcmat-l1

I found that the small, separate harness which joins the coils had been reversed. Similar to what you described, the cable ran 7-5-3-1, instead of the correct 1-3-5-7. It runs like a top, now...no more backfire, and explains why it took so darn long for it to heat up!
Now I have to solve the 'why is the oil pressure so low' issue? 18 lbs hot
Thanks alot for your direction, and have a great time in the Rhineland and Austria!
Glenn
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Good deal. Glad I could help.