Ever spend an entire working day swapping injectors? I haven't, until recently. I wish I could still say that without the qualifier though.
If you ever have the opportunity. Pass.
I've been having issues with the fuel in my MJ, basically it is running to rich on the top end, so recently I spent a whole day swapping injectors (21 lb-hr and 24 lb-hr) and regulators (39, 45, and 50 -lb pressure) to see if I could cure the fat problem on the top end while keeping it running good during most driving.
The OBD1 Jeep reads the O2 sensor 99-percent of the time during normal operation. The two exceptions are at cold start up and at wide open throttle. So, at wide open throttle, the Jeep reverts to the factory fuel map based on the inputs it is seeing. I'm seeing 10:1 A/F ratios at wide-open and I need more like 12.5 or so. I can see the correlation on the dyno graph to where the truck dumps fuel. So, I blew a day with injectors and regulators.
It basically goes like this:
wait to cool, or burn myself
Lube and install new o-rings and injectors
Reinstall ancillary parts
take for at least a 20-30 mile drive so the computer can figure itself back out.
Run a couple of wide-open high-load passes and see what it does on the AEM wide-band O2 gauge
At the end of the day, I ended up back where I started.