LB7 fuel junction block

[SHOTZY]

Is there a return valve in the junction block that could cause excessive fuel return?

 

[bullfrogjohnson]

Yeah there is a relief valve in the junction block located near the upper coolant pipe under the air filter. Its a big 22 mm bolt head with copper washers. Its inside there. You have to either replace it or tap the inside for a set screw. There are a couple threads on it.

 

[TrentNell]

Is there a return valve in the junction block that could cause excessive fuel return?

X2 on what Travis said , they are not known for leaking though but you can check it with a bottle test , Injectors can cause the same issue also so some testing needs to be done if you need the info on the cylinder hear return test let me know i can post it up .

 

[SHOTZY]

Thanks guys. Did the test on the return valve. Its good. However right bank of cylinders returned 20 ml. Now checking individually to rule out a bad one. There is one thing I forgot to tell you guys. When the heads were off one got knocked over and landed on two of the injectors breaking the soelenoid on them. Replaced those. Any other ideas?

 

[05smoker]

I think you have injector issues (cracked bodies). Mine wouldn't build rail pressure when they were bad, even with dual pumps.

 

[maine04max]

blocking off the return is one thing i didnt do . you guys think this is necessary ?