I ran some test runs, with the scanner hooked up and learned a lot! Under load and at WOT, the ICP would quickly drop from 2,800PSI to 1,089PSI. I ordered a TE modded 17* HPOP and installed it today. I didn't order it with an IPR and figured I would use the IPR seal kit I already had. Unfortunately, I couldn't find the kit!
I found some O-rings at NAPA and put them on the IPR. They worked like a charm. The HPO pump install went off, without a hitch. No leaks, ran rough for about 10 minutes and cleared right up. The truck is still smoking though and I think I found out why.
I tried saving some money and bought a glowshift fuel pressure gauge. It read correctly, when I had the FPR shimmed to 62PSI. It did NOT read correctly, when under load. According to that gauge, the pressure never went below 50PSI under load. It started acting screwey, so I replaced it with a better gauge. Not the most expensive gauge I could buy, but I'm still paying back the loan I got for the new set of injectors.
With the new gauge, pressures are a lot different. I still had the 62PSI at idle, but any throttle would make it drop quickly. Under load, it went down as far as 5PSI. I didn't let it stay that low and limped the truck home. I replaced the fuel pump, with a pump I had bought for an OBS e-fuel conversion and shimmed the FPR to 70PSI. This time, the pressure didn't drop nearly as fast. I did drop to just under 30PSI at WOT and I backed out of it when it did. Thinking I had a fuel restriction, I replaced the fuel filter. The filter was not the restriction.
Evidently, I either have a fuel restriction somewhere, or another bad fuel pump. The old pump was quite noisy and I could hear it bog down, when it got up to 62PSI. The pump I installed this evening is a lot more quiet, but I can also hear it bog down, when it gets up to pressure.
With the low fuel pressure I have been running unknowingly, I think I've gone and hosed yet another set of injectors.. Unfortunately, there is no possible way for me to be able to afford another set.