In the Tech article about troubleshooting fuel pressure issues https://blazerforum.com/forum/tech-a...agnosis-23038/
a member made a similar fuel shutoff adapter. I made this one this weekend similar to a Kent Moore J-42964-2 and wanted to post instructions and parts needed in case someone else wanted to do this. This is needed to isolate the fuel return line from the rail back to the tank and troubleshoot a faulty fuel pressure regulator.


DIY Fuel line shutoff adapter
Similar to Kent Moore J-42964-2
5/16 quick connect fuel return line (2001 Chevy Blazer 4.3L)
Used to isolate fuel return and check pressure regulator
You also make 3/8 adapter for feed line with one additional part (similar to Kent
Moore J-42964-1 without Schrader valves) and some additional fuel line.

Parts needed:
1. Dorman 800-084 (5/16 steel to 3/8 nylon quick connecter) $6.99
2. Dorman 800-159 (12 “ 5/16 and 3/8 steel repair tubes) $16.99
3. 3 feet of 3/8 fuel line $ 3.60
4. 4 clamps 10 pk for $2.09
5. 2 ¼ MIP to 3/8 hose adapters (Home Depot P/N A-293 $2.67/ea) $5.34
6. ¼ inch ball valve (Home Depot) $7.40

Optional Parts for 3/8 shutoff adapter
Dorman 800-082 (3/8 steel to 3/8 nylon quick connecter $6.99)
3 additional feet of 3/8 fuel line ($3.60)
4 clamps $0 (6 left over from above)

Making the adapter is quite simple using the above parts (1-6) and see photos. One additional note is when I cut the 5/16 steel fuel line the fit with the 3/8 fuel hose was loose so I flared the end and double clamped it. Use Teflon tape on the 1/4 MIP to 3/8 hose adapters when attaching to to shutoff valve.