Fuel Pressure issue
Fuel Pressure issue Hi,
I have a 99 ss camaro(see sig for details)
When tunning the car we ran into a fuel pressure problem.
I wasn't able to hold 55 PSI.
The car had a stock pump in the tank and an inline booster pump for vortec.
to fix the problem I installed a racetrontix in-tank upgrade pump & an MSD volyage booster to the in-line pump. At this point I had 65 PSI until about 4000 RPM and would drop to about 58 PSI by about 5900- 6000 RPM. The car isn't driven a lot and will sit for 3-4 weeks at a time. Recently I have found that at around 4000 RPM I am not able to hold the 55 PSI and infact it will drop down to around 40 PSI. at which time cause the motor to lean out and not run properly.
My question is why?
I changed the in-line fuel filter. tested the inline pump to see if it is working. it is. I turned up the voltage booster to full (16.5 volts @ 10PSI boost).
I'm thinking that the tank pump is starving for fuel.
what else should I do?
Thanks in advance for the help
Al
I have a 99 ss camaro(see sig for details)
When tunning the car we ran into a fuel pressure problem.
I wasn't able to hold 55 PSI.
The car had a stock pump in the tank and an inline booster pump for vortec.
to fix the problem I installed a racetrontix in-tank upgrade pump & an MSD volyage booster to the in-line pump. At this point I had 65 PSI until about 4000 RPM and would drop to about 58 PSI by about 5900- 6000 RPM. The car isn't driven a lot and will sit for 3-4 weeks at a time. Recently I have found that at around 4000 RPM I am not able to hold the 55 PSI and infact it will drop down to around 40 PSI. at which time cause the motor to lean out and not run properly.
My question is why?
I changed the in-line fuel filter. tested the inline pump to see if it is working. it is. I turned up the voltage booster to full (16.5 volts @ 10PSI boost).
I'm thinking that the tank pump is starving for fuel.
what else should I do?
Thanks in advance for the help
Al
If you have a Racetronix, the inline pump is probably a restriction to the intank pump. Try it without the inline to see if it is any better.
Your Racetronix should support at least 550rwhp without problem. If you still come up short, I can set you up with a dual intank setup.
Your Racetronix should support at least 550rwhp without problem. If you still come up short, I can set you up with a dual intank setup.
I have the same problem with my fuel system. A lot of people say that a walboro fuel pump with a boost a pump or a racetronics hot wire will help, but I'm here to say it frankly does not. I have both the BAP and the hot wire and my fuel pressure always falls to about 40-45 under full boost (8.5 lbs.) I'm at 525rwhp/511 rwtq so I'm left scratching my head. I'll eventually send my sending unit to Lonnie so he can install a double pump but that will have to wait for now.
The biggest problem is the rear mounted regulator. As engine flow increases, the pressure drop due to line restriction is detected, but the pump may very well still be making 60# at the tank. The only way to accurately detect this would be to add a gauge at the fuel filter to see the actual difference from the reading at the motor.
As far as power level, the single pump has fed forced induction to around 600rwhp, but every application is different due at air/fuel ratio setting as well as the pressure it was tuned at. I usually say 550 is the practical limit with forced induction.... your results may vary.
I always choose to provide extra fuel capacity as it is better safe than sorry when it comes to leaning out a motor.
As far as power level, the single pump has fed forced induction to around 600rwhp, but every application is different due at air/fuel ratio setting as well as the pressure it was tuned at. I usually say 550 is the practical limit with forced induction.... your results may vary.
I always choose to provide extra fuel capacity as it is better safe than sorry when it comes to leaning out a motor.
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My pump is acting like its maxed out. When we tried to change the tune the pump did not respond at all. It was so bad it was put to 11:1 but the a/f never went below 13:1. On the runs the car put down 430rwhp NA so I figured the racetronix kit was no where near maxed out. Any idea what could cause it to do that? I have #42 svo injectors as well.
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Originally Posted by Tirefire
I have the same problem with my fuel system. A lot of people say that a walboro fuel pump with a boost a pump or a racetronics hot wire will help, but I'm here to say it frankly does not. I have both the BAP and the hot wire and my fuel pressure always falls to about 40-45 under full boost (8.5 lbs.) I'm at 525rwhp/511 rwtq so I'm left scratching my head. I'll eventually send my sending unit to Lonnie so he can install a double pump but that will have to wait for now.
I have a hot wire setup in the car and an MSD voltage booster on the in-line pump. It will hold 65 PSI until about 8 PSI boost then starts dropping down to About 58 by 10 PSI boost. I'm at about the same RWHP 535RWHP / 505 RWTQ.
Originally Posted by Lonnies Performance
The biggest problem is the rear mounted regulator. As engine flow increases, the pressure drop due to line restriction is detected, but the pump may very well still be making 60# at the tank. The only way to accurately detect this would be to add a gauge at the fuel filter to see the actual difference from the reading at the motor.
As far as power level, the single pump has fed forced induction to around 600rwhp, but every application is different due at air/fuel ratio setting as well as the pressure it was tuned at. I usually say 550 is the practical limit with forced induction.... your results may vary.
I always choose to provide extra fuel capacity as it is better safe than sorry when it comes to leaning out a motor.
As far as power level, the single pump has fed forced induction to around 600rwhp, but every application is different due at air/fuel ratio setting as well as the pressure it was tuned at. I usually say 550 is the practical limit with forced induction.... your results may vary.
I always choose to provide extra fuel capacity as it is better safe than sorry when it comes to leaning out a motor.
I have a fuel pressure gage with the sensor at the fuel rail.
I would agree with the better safe then sorry statement.
Originally Posted by xxtheonlyxx
My pump is acting like its maxed out. When we tried to change the tune the pump did not respond at all. It was so bad it was put to 11:1 but the a/f never went below 13:1. On the runs the car put down 430rwhp NA so I figured the racetronix kit was no where near maxed out. Any idea what could cause it to do that? I have #42 svo injectors as well.
The fuel filter could need to be changed.
also try it with a full tank, the thought is the pump may be starving because the can that it runs in could be running dry.
Just a thought
Originally Posted by STKN1STGEAR
It could be the dia of the fuel line or even a pinched fuel line like I had.
The fuel filter could need to be changed.
also try it with a full tank, the thought is the pump may be starving because the can that it runs in could be running dry.
Just a thought
The fuel filter could need to be changed.
also try it with a full tank, the thought is the pump may be starving because the can that it runs in could be running dry.
Just a thought
Originally Posted by Tirefire
I have the same problem with my fuel system. A lot of people say that a walboro fuel pump with a boost a pump or a racetronics hot wire will help, but I'm here to say it frankly does not. I have both the BAP and the hot wire and my fuel pressure always falls to about 40-45 under full boost (8.5 lbs.) I'm at 525rwhp/511 rwtq so I'm left scratching my head. I'll eventually send my sending unit to Lonnie so he can install a double pump but that will have to wait for now.
Originally Posted by STKN1STGEAR
I found the problem--- when I installed the in-line pump I pulled the plastic line to tight and it started to kink. After fixing the kink the fuel pressure will only drop down to 58 at 10 PSI boost.
I have a hot wire setup in the car and an MSD voltage booster on the in-line pump. It will hold 65 PSI until about 8 PSI boost then starts dropping down to About 58 by 10 PSI boost. I'm at about the same RWHP 535RWHP / 505 RWTQ.
I have a hot wire setup in the car and an MSD voltage booster on the in-line pump. It will hold 65 PSI until about 8 PSI boost then starts dropping down to About 58 by 10 PSI boost. I'm at about the same RWHP 535RWHP / 505 RWTQ.
Originally Posted by Tirefire
What plastic line are you exactly talking about???
