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Fuel pressure …what am I missing

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Robnan8028

New Member
Help! I’m new here and hoping someone can help. Fuel pressure is 30 lbs at pump prime, key on motor not running. Way to low. Replaced fuel regulator with bbk and it shot one second after running. So I put on another regulator, was able to adjust but I thought I had adjusted it to much and regulator free flowed. If I pinch return line it maintains pressure .so I replaced again . This time pressure is at 30 and when I turn off key it drops to 20 lbs. so I replaced pump, no luck, same thing. So I pulled rail off and zip tied injectors to rail so they wouldn’t pop off and tried same thing but no injectors are leaking or open. I think I hear an leak but I can find any. I think I’m hearing the return fuel. But I’ve tried adjusting regulator and it wont bring up pressure. So I am dumbfounded and hope someone hear can help
 
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Robnan8028

New Member
347HO said:
I got nothing...

Why are you shooting the fuel system in the first place?
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Well, I’m so frustrated I’d like to shoot it , but I was referring to messing the regulator up by adjusting it too far. Today I disconnected all my injectors from the harness thinking it might be a ground short but no luck. I’m going to take off the fuel rain and bench test the injectors as it has to be one of them because I pinched the return line then with key on I pinched the supply line and the pressure still dropped. It’s driving me nuts as I just put brand new injectors on
 
fb1376

fb1376

New Member
Pinch off the return line but leave the supply line alone. Prime the pump and turn the key off. If the pressure bleeds off, check the regulator vacuum line for fuel. If there is fuel, the regulator is leaking. But if its dry, then its one of the injectors leaking. If the pressure doesnt bleed off, its the pump. IIRC.

Testing new injectors is always a good idea tho. Brand new never used, rebuilds, and especially cheap aftermarkets. New doesnt always mean its good.
 
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Robnan8028

New Member
fb1376 said:
Pinch off the return line but leave the supply line alone. Prime the pump and turn the key off. If the pressure bleeds off, check the regulator vacuum line for fuel. If there is fuel, the regulator is leaking. But if its dry, then its one of the injectors leaking. If the pressure doesnt bleed off, its the pump. IIRC.

Testing new injectors is always a good idea tho. Brand new never used, rebuilds, and especially cheap aftermarkets. New doesnt always mean its good.
Click to expand...
Any suggestions on how to test the new injectors. My injectors don’t have clip retainers to hold them to rail so lifting rail up and turning key on will just push the injectors off. And I actually did the pinch test on return line and pressure dropped. So then I pressurized the fuel rail with the return line still pinched and while the the key was on i pressurized the supply line and then turned off key. Pressure still dropped so I know we have an issue with injectors but at a stand still on how to check each one. I guess I could remove spark plugs and look for one that is saturated but I tried this and found nothing but I’m going to try again
 
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