Rusty water in radiator and recovery tank after sitting for three years in 1991 explorer with 280k m

after sitting on a steep driveway for three years, no starting done all that time,I filled all tanks, started it up, drove it on and off 8 times for 50 miles, air in top radiator tank along with rusty water, dare we flush the system being 280k miles old with 40k on new radiator/ also is there a socklike screen over the fuelpump in the tank that may need cleaning to help it start quicker than two to three starter attemps?

Flushing the cooling system won’t hurt but don’t be surprised if the water pump starts leaking at some point due to aged, dried out seals. It won’t be the flush that caused it.

There’s a sock in the tank but that is not likely the cause of hard starting. It could be that the difficult starting is caused by loss of residual fuel pressure due to the check valve in the fuel pump not sealing correctly while the engine is not running. This can be checked with a fuel pressure tester.

You might try turning the key to RUN for a few seconds without cranking the engine and then turning the key back off. Repeat this several times and if the engine fires right up then odds are the check valve is at fault although there are a few other things that could cause loss of fuel pressure.
The only cure for a leaking pump check valve is pump replacement. Hope that helps.

This helps a lot, thank you. we tried the on-off key on RUN effort with no effective change.When we had filled the tank, we added a brand name fuel system cleaner and fuel drier, replaced the inline filter. starting after 3to4 attempts was then the only issue and it accelerated fine, until we went out on the highway. we were going along at 65 mph doing great and had to speed up to 75 to remain in the flow and suddenly the engine lost power and after numerous evasive moves to reach the shoulder, we hobbled to the next exit and made our way home on side streets.since then, I have driven it locally only at 25mph and its fine, even started on 2 start tries, (little better). my friend says it seems inevitable that we are going to have to drop the skid plate, tank and pull the fuel pump and likely replace it.I will do the pressure test first that you suggested (thanks) to see if the residual pressure changes when off power. I suppose a volume check after the filter would make sense, i don’t know what that should be. Any confirmation or detraction or additional information would be really appreciated since we are looking to tow a 1954 VW beetle from San Diego to Washington state soon with either a tow bar or on a rented car dolly and we are not sure which would be better. We are thankfully open to suggestions and advice

I would not flush the cooling system, but if you do flush it with regular water, it probably won’t hurt anything. If you are thinking of a chemical flush, don’t do it. You will have some serious issues with the cooling system if you do.

I would drain the block and radiator and refill with either the 50/50 premix or mix my own full strength antifreeze at a 2:1 ratio of antifreeze to distilled water. Inspect all you hoses before doing this, you don’t want to go to all this trouble to only have a hose break and you loose it all. REPLACE the radiator cap while you are at it.

I have made a lot of cross country trips in some very questionable vehicles, but you would be pushing the envelope for me. If the beetle runs, then at least then you have a back up vehicle if he primary does break down.

I think you need to replace the fuel pump.