Fuel pressure holds at 70psi but not at 60psi??? (WOT)
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Fuel pressure holds at 70psi but not at 60psi??? (WOT)
The pump bleeds off after priming no matter what pressure it's set at. At 60psi it will hold pressure at idle and light loads, but under WOT it drops to about 40. I replaced the almost new racetronix pump with another new racetronix pump and it was still doing the same thing. I then replaced the rest of the system with -6 lines, billet rails, and aeromotive reg... still same problem. I recently set the pressure to 70psi (idling) and it holds constant at 70 even at WOT. It sounds to me like the check in the pump is bad but it seems strange that 2 new pumps both have bad checks. Anyone have any other ideas?
BTW, I know I have another thread about this but it was 4 years old and had too much clutter.
BTW, I know I have another thread about this but it was 4 years old and had too much clutter.
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If that's the case, why would the pressure hold solid with it set at 70psi? The only way that would make sense is if the regulator was bad but I put the stock reg back in and it was still dropping. This whole time I've been thinking that there was an internal leak in the bucket somewhere but a leak wouldn't stop at a higher pressure.
#6
If it is leaking at a consistent rate and only allows a certain amount of fuel to squeeze through, then adding pressure may have just masked the problem. The only time I have seen a fuel pressure loss problem with a new pump @ WOT, it was caused by either an in tank leak, voltage drop at higher rpm, bad regulator, kink in the feed line or the pump is too small for the setup.
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I guess the only thing it could be at this point is an in tank leak. It just seems really strange to me that it would drop 20psi while set at 60 yet doesn't drop even 1psi while set at 70. No matter, I decided to switch to E85 so I have a complete new fuel system on the way. If it's still losing pressure after that I'll get a new sending unit and be done with it.
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I suppose it could be a kinked line but also seem very unlikely. I've had the pump out at least a dozen times trying to figure this crap out and have tried to be careful putting it back in each time. I got my new E85 pump today so I'll swap that out and be sure to seal everything up. Hopefully the problem will go away then.
Thanks for the input guys, this thing is confusing the hell out of me...
Thanks for the input guys, this thing is confusing the hell out of me...
#14