First time posting on the forum, but a frequent visitor. Thanks for all the past help.

I have a 2004 Disco II that has decided to start running poorly and I can't figure out why. It idles rough with frequent misfires and stumbles and low power. If you try to drive it, it starts bucking / surging as soon as the convert locks. On startup, it revs to about 1,000 rpm then immediately drops to barely 750 rpm (no cold high-idle) and frequently almost stalls.

These issues began after I attempted to start driving it again after it sat for about 3 months. It began as an intermittent issue that would come and go, but is not constant.

Here's the list of codes my basic OBDII reader is currently getting:
P0414 - SAI
P0418 - SAI
P0445 - Evap
P0448 - Evap
P0261 - Injector Low Circuit
P0264 - Injector Low Circuit
P0267 - Injector Low Circuit
P0270 - Injector Low Circuit
P0273 - Injector Low Circuit
P0276 - Injector Low Circuit
P0279 - Injector Low Circuit
P0282 - Injector Low Circuit - that's all 8
P1451 - Evap
P1482
P1513 - IACV
P1552 - IACV
P1664 - TPS?

Troubleshooting so far:
- Checked batteries (dual batteries) and topped up charge
- Checked engine bay grounds
- Replaced air filter
- Checked spark plugs and wires
- Replaced fuel pump relay
- Cleaned computer plugs
- Removed serpentine belt (to make sure an accessory wasn't dragging)
- Replaced fuel pump
- Measured fuel pressure - 50psi while running
- Inspected fuel injector harness - battery voltage with key on to all injectors
- Measured fuel injector resistance - all about 14 ohms
- Replaced SAI pump - original measured 0 ohms
- Replaced evap valves at engine (I was there)
- Replaced IACV - original was clean and seemed fine

I'm not sure where to go from here. My thoughts are that I might have a damaged power distribution box from the short circuited SAI pump (no sign of damage from the top or on relays) or maybe that the computer has decided it had enough of life. Or maybe (hopefully) there's a magic ground somewhere that I haven't found that likes to go bad - the ground under the computer looks like it has a broken off terminal, but there's no loose wires around...

Any input is appreciated. Thanks for reading my novel of a post and thanks in advance for the help.

 

The injector low circuit does seem to indicate a ground or ECU issue, which could cause all of those other codes as well. If it was one of mine I would swap the ECU and see what happens (I keep spares). You need to buy a matched ECU/BCU and you might want to consider getting the Instrument cluster as well or just use a nanocom to turn off the flashing in the ODO that will occur from running a non-matched BCU/IC. It is a good idea to have a spare anyway, they aren't making any more. You can get one from one of the breakers on Facebook - try Will Tillerey (on facebook as Meredith-Will TIllerey).

 

Replaced the ECU / BCU and the issue is fixed. Thanks for the confirmation on ECU issue.