Fuel Pressure dropping
Thread Starter
Launching!
Joined: Sep 2004
Posts: 246
Likes: 0
Fuel Pressure dropping Setup: 408 LQ9 with P1SC
Fuel: 2 walbro 255's, 1 in each tank (1999 C5)
Tune: OLSD with AEM Wideband
Primary pump is on drivers side and is always on. Secondary kicks in at 3k rpm. There is a regulator on the rail.
Just cruising right after startup, when you tip in to the throttle for WOT, pressure drops 2-4psi. After running around a while (just cruising) and the engine temps come up to 200, it seems like when you get on it, the FP immediately drops like 10psi from 58 to 48.
Could this be the fuel beginning to vaporize? Could it be the pump? When the 2nd pump kicks in at 3k the FP stabalizes back to normal 58psi, but we're tryin to figure out why the primary pump is losing pressure. Guy who is building the car thinks it needs a fuel controller because it is circulating the fuel too quickly and allowing it to heat up in the process.
?????
Fuel: 2 walbro 255's, 1 in each tank (1999 C5)
Tune: OLSD with AEM Wideband
Primary pump is on drivers side and is always on. Secondary kicks in at 3k rpm. There is a regulator on the rail.
Just cruising right after startup, when you tip in to the throttle for WOT, pressure drops 2-4psi. After running around a while (just cruising) and the engine temps come up to 200, it seems like when you get on it, the FP immediately drops like 10psi from 58 to 48.
Could this be the fuel beginning to vaporize? Could it be the pump? When the 2nd pump kicks in at 3k the FP stabalizes back to normal 58psi, but we're tryin to figure out why the primary pump is losing pressure. Guy who is building the car thinks it needs a fuel controller because it is circulating the fuel too quickly and allowing it to heat up in the process.
?????
Thread Starter
Launching!
Joined: Sep 2004
Posts: 246
Likes: 0
Well, we ended up getting a fuel conroller to turn down the voltage at cruise and this solved the problem completely. I didnt believe that it would at first, but it is like magic lol
What was happening is that it was cycling the fuel too quickly and the fuel was getting really hot. With the controller on there now, the fuel in the tank has plenty of time to sit and cool off before being pumped.
What was happening is that it was cycling the fuel too quickly and the fuel was getting really hot. With the controller on there now, the fuel in the tank has plenty of time to sit and cool off before being pumped.
