I have been fighting this since I put the V10 in. NEVER throws a code, but I see the fuel trims go lean on one side and rich on the other. I keep finding new stuff to cause it. Broken coil or injector connectors, water in plug holes, bad coils (maybe), rotted boots, etc. Well now it has brand new non-China coils and boots and numerous new connectors soldered in. As usual ran perfect for a while then starts shaking under a load.

I think I may have finally solved it for good. The LTFT's have always been a bit more positive than I'd like - around 10-12% - so I pulled the injectors out yesterday and ran them through the heated sonic cleaner for an hour. I found one the leaked when I clamped an air hose to the inlet. Some brake cleaner and reverse flushing solved the leak.

It seems to have a little more bottom end now, the fuel trims have settled down to around 7%, so the injectors were definitely suffering. Hopefully the tiny V10 will stay running right since it's my primary transportation for the next couple weeks.