Strange Fuel Pump Priming and Pressure Q
03-12-2016, 10:50 PM
#1
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Strange Fuel Pump Priming and Pressure Q I removed my injectors to have them tested to make sure they weren't leaking. Everything checked out perfect on them. However, now that I've reinstalled them, the pump primes for about 27 seconds rather than the few seconds like it used to. When the key is turned to the 'ON' position, the fuel pressure jumps to 47 PSI and holds steady, them when the pump is done priming, the pressure drops to 32 PSI.
Also, when the car is running, it idles steady and pressure stays steady at about 45 PSI, but if I rev the motor, it drops to 40 PSI. I'm not sure if that's normal. I've attached a video of the priming if you can see it. Anyone else ever experience this or have info on it?
Also, when the car is running, it idles steady and pressure stays steady at about 45 PSI, but if I rev the motor, it drops to 40 PSI. I'm not sure if that's normal. I've attached a video of the priming if you can see it. Anyone else ever experience this or have info on it?
03-12-2016, 11:47 PM
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Oh, and I forgot to add; the fuel system is a Racetronix duel in-tank pump setup with a stock fuel pressure regulator.
Last edited by Snorkelface; 03-13-2016 at 11:07 PM.
03-13-2016, 02:53 PM
#3
Pending how responsive your tune and turbo are, when you rev it odds are you are raising the vac level in intake so makes sense your FP will go down. Its a 1:1 with boost or vacuum. Just make sure you tune is accounting for that and that it rises with boost. (The important part lol)
I do not think anything related to fuel rail should have any affect on the prime time circuit, so my guess is that they are not related.
I do not think anything related to fuel rail should have any affect on the prime time circuit, so my guess is that they are not related.
03-13-2016, 03:52 PM
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Okay, got it, I'll look into that, thank you.
It's just really weird. It never did this before. What zits cause the prime circuit to activate so long assuming there aren't any other issues?
It's just really weird. It never did this before. What zits cause the prime circuit to activate so long assuming there aren't any other issues?
Pending how responsive your tune and turbo are, when you rev it odds are you are raising the vac level in intake so makes sense your FP will go down. Its a 1:1 with boost or vacuum. Just make sure you tune is accounting for that and that it rises with boost. (The important part lol)
I do not think anything related to fuel rail should have any affect on the prime time circuit, so my guess is that they are not related.
I do not think anything related to fuel rail should have any affect on the prime time circuit, so my guess is that they are not related.
03-13-2016, 07:56 PM
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I'll probably try changing the fuel pressure regulator just to check it since after that it could only be the pump. I'm surprised no one else has experienced this, I must be special. Haha
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03-15-2016, 12:42 AM
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No, it's wired to it's own relay. But now that I think of it, I'll try switching which pump is the main one and see if that makes a difference.