Enough Fuel?
05-13-2006, 09:38 PM
#1
Staging Lane
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Enough Fuel? Hey guys got a quick question, I have a in tank 255lp pump and an autometer fuel pressure(electrical) gauge that reads around 52psi at idle, and 44psi under full throttle. Is that enough fuel pressure to spray on or not?
05-13-2006, 11:07 PM
#3
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Well what do you suggest? I got the fuel pump from Dave but I thought it would of been enough or is running 42# inj to much of a demand on the fuel pump? All the other cars that i have put the racetronix pump have around 60ish psi at idle at the rail why not mine? Is there something that Im missing or could in be that I have a fuel pressure switch, fuel soleniod, and the fuel pressure gauge all at the end of the fuel rail?
05-14-2006, 03:43 AM
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When is the last time you changed the filter? That pressure is not right for an LS1. On a wet you'd risk going lean, dry you might expound on your insufficient fueling issue. I agree, I wouldnt spray it until you get it 58psi idle and WOT. Check filter? Check the supply hose in the fuel pump module..I know mine would run fine, but the hose was split about 1" long down the side. It was the "hi-pressure" line that came with the Walbro pump. I replaced it with some low pressure (600psi) rated hydraulic hose and a rounded edge clamp. No issues since.
05-14-2006, 09:33 PM
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Ok let me throw this in there to the car had the same issue with the stock pump. So to solve that I installed an inline 255 but that did nothing, I since have changed my fuel rail and regulator. After all that I went to the intank 255 and still have the fuel pressure do you think it could be the sending unit for the fuel pressure gauge, or you think I have got some other issues????
05-15-2006, 01:25 AM
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Your saying your fuel pressure was low before, then you added an inline, still low, added rails and stock regulator still low, took out inline pump and added intank 255L pump still low?
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05-15-2006, 08:56 AM
#9
With the mods you have the intank walboro should be enough to support the needed fuel demand for NA but not on the spray. A hotwire kit added to your walboro pump will be good for about 650ish...
This is what I would do. I would get a test gauge like what is used at the shop. This is a machanical gauge and it has enough hose to screw onto the schrader valve and route up to the front. Check the idle fuel pressure and when you are driving the car on a punch. There is a chance that any after market gauge not being real accurate.
If the pressure is still low it sounds like its time to pull the sending unit out and swap it for another. The car must have a bad fuel pressure regulater (inside tank). The thing you see sitting on your fuel rails is a fuel dampner not a fuel regulater.
Dave
This is what I would do. I would get a test gauge like what is used at the shop. This is a machanical gauge and it has enough hose to screw onto the schrader valve and route up to the front. Check the idle fuel pressure and when you are driving the car on a punch. There is a chance that any after market gauge not being real accurate.
If the pressure is still low it sounds like its time to pull the sending unit out and swap it for another. The car must have a bad fuel pressure regulater (inside tank). The thing you see sitting on your fuel rails is a fuel dampner not a fuel regulater.
Dave
05-15-2006, 09:33 AM
#10
Originally Posted by Nitro Dave's Nitrous Outlet
The car must have a bad fuel pressure regulater (inside tank). The thing you see sitting on your fuel rails is a fuel dampner not a fuel regulater.
Dave
Dave
05-15-2006, 08:38 PM
#12
Staging Lane
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Dave thanks for the info but the pump I have is the same as the one I got from you last week for the 99 I think it has the hot wire kit. So do you think that my fuel regulator is bad and that is why the new pump did nothing. I did get the pump that is in my car from Juan Gonzalez second hand so I dont know how old it is or what?
05-15-2006, 08:45 PM
#13
Ohh ok. So you have the racetronix kit. Juan had just got that thing from me and gave it to you like the next week in yalls trading.lol. So its pratically new. I hate to tell you this but I think if you have tried evrything including fuel filter change thats all you have left to look into. Its going to be the most expensive fix to. But you need to do it before spraying.
Dave
Dave
05-16-2006, 09:47 PM
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Ok guys problem solved. I hooked up a manual fuel gauge like Dave explained and tghen looked at the pressure..It was around 62ish at idle and under full throttle it was at 58ish psi. So it was the auto meter gauge that was reading about 10psi lower than the rail. Thanks for all the help and input, now I can go spray it on the dyno and the track I will let you know how it goes.