Yes, TBI and the fuel filter is new, but I know when we cut the old one out (cut it out due to corrosion so bad on the fittings) that pretty nasty rusty sludge came out of the old one. I have no idea condition of the inside of the tank or the age of the current fuel pump and sender. Judging by the rusty bolts and straps it has been in there a while.
I don't understand how a fuel line cleaner would add restriction but if that is the case it would be very simple now to replace the fuel filter again since I have repaired metal lines on both side of the filter (where someone had used rubber hoses to patch it in) and the fittings on the current fuel filter are brand new so easily removed.
I dropped off the truck tonight (much longer story) to get the transmission rebuilt. We were getting slow activation into reverse and slipping if trying to back up a slight grade. We were occasionally getting a hard shift between one/two but only if steady pressure on accelerator was holding rpms up before the shift. I debated finding a rebuilt one and putting it in but research showed that this transmission was unique in its attachment to the transfer case in the 1995 year and would be very hard to find that exact setup in a rebuild shop.
While it is on the hoist they will check transfer case, seals, and look for any unusual findings. I asked while the tranny was out to drop the oil pan and put a new gasket in since I think the slow drip off the bell housing of oil was coming from the leaking oil pan gasket.
Of course none of this relates to the new issue with the engine not appearing to pump enough fuel right at startup to keep running on the first try.
One other variable but hopefully it is not related, there are posts on this forum where a hard 1-2 shift was related to low power on one of the wires going to the ECM. The video shows very clearly the problem with the low voltage giving a higher than normal pressure build up and a hard 1-2 shift. I did swap my ECM computer and PROM using an exact match from a donor 1995 chevy. The truck ran normally after this switch for about 2 weeks so not sure that could still relate. I guess I could easily swap back to the original ECM or at least swap the PROM back as a troubleshooting step.
This project has been way more expensive and time consuming then every imagined. We have faced nearly every hurdle mentioned in this forum.
Assuming the rebuilt transmission will be solid for a long time and it goes well, I was toying with LS swap but the price tag is insane. Swapping a 350 TBI probably won't give much of a difference. I think we may just have to stick with the 305 for now and try to idealize its performance. The tranny shop guy has some history of doing a few LS swaps and he said before we go through the time and cost for limited improvements in power, (it is a 5.3L vs 5.0L displacement), he said our budget could more easily handle the simpler task of putting a slightly 'souped up' cam (he mentioned an RV cam). But that is only after we get the engine starting and running normally again.