Fuel Experts Please! 99 Vortech/Built FRC
Thread Starter
Melting Slicks
Joined: Nov 2003
Posts: 2,213
Likes: 135
From: In front!
Fuel Experts Please! 99 Vortech/Built FRC
I have never heard of a problem like this before. Hopefully, one of you has!
My tuner I were out tuning the car tonight when we noticed two things after a while.
1) On a second gear pull, the car violently fell on it's face. It literally felt like someone was clamping the fuel lines off. It was not doing this earlier in the night!
2) During our third and fourth gear pulls, I had to get out of it because the car was leaning out up top; say, above 5000-5250 RPM's. It was not doing this a couple days ago.
Well, needless to say, we were baffled. Car runs and drives great under normal throttle! The car has an LPE pump, BAP, Racetronix harness, 60LB injectors, 100% meth, and is currently showing 10 PSI on a boosted low compression motor. Plenty of fuel right?
Here is the crazy part that makes no sense!
Car started having problems when we were showing a bit less than 1/2 a tank of gas. We called it a night to do some research. On the way home, I topped off the tank, and it took almost 9 gallons, so, I know that the fuel gauge was fairly accurate. With a full tank, the car does not fall on it's face anymore and the car also runs perfect up top...it's even too rich now because of the extra fuel we added...at 6K in 3rd and 4th, the A/F is 10.2-10.5 with the full tank and runs perfect (well, perfect for a car running pig rich!!
EDIT: One more thing. I let the gauge hit just below an 1/8th of a tank a few weeks ago and it actually ran out of gas...the factory pump was replaced with the LPE pump.
Can someone please tell me what the heck is going on?!?!?!?
My tuner I were out tuning the car tonight when we noticed two things after a while.
1) On a second gear pull, the car violently fell on it's face. It literally felt like someone was clamping the fuel lines off. It was not doing this earlier in the night!
2) During our third and fourth gear pulls, I had to get out of it because the car was leaning out up top; say, above 5000-5250 RPM's. It was not doing this a couple days ago.
Well, needless to say, we were baffled. Car runs and drives great under normal throttle! The car has an LPE pump, BAP, Racetronix harness, 60LB injectors, 100% meth, and is currently showing 10 PSI on a boosted low compression motor. Plenty of fuel right?
Here is the crazy part that makes no sense!
Car started having problems when we were showing a bit less than 1/2 a tank of gas. We called it a night to do some research. On the way home, I topped off the tank, and it took almost 9 gallons, so, I know that the fuel gauge was fairly accurate. With a full tank, the car does not fall on it's face anymore and the car also runs perfect up top...it's even too rich now because of the extra fuel we added...at 6K in 3rd and 4th, the A/F is 10.2-10.5 with the full tank and runs perfect (well, perfect for a car running pig rich!!
EDIT: One more thing. I let the gauge hit just below an 1/8th of a tank a few weeks ago and it actually ran out of gas...the factory pump was replaced with the LPE pump.
Can someone please tell me what the heck is going on?!?!?!?
Last edited by Y2KRoadster; Aug 10, 2012 at 03:31 AM.
Pro
Joined: Oct 2006
Posts: 515
Likes: 134
Left tank, which feeds the engine, should remain near full as the right tank empties. This can be checked by monitoring the tank sensor output voltages with a Tech II or a voltmeter.
It may be possible that the jet pump circuit which pumps from right to left is not conpletely inoperative but is obstructed in such a manner that it cannot keep up with the increased fuel flow with your mods. I say this because your engine did not quite, which is what usually happens with no transfer at all.
It may be possible that the jet pump circuit which pumps from right to left is not conpletely inoperative but is obstructed in such a manner that it cannot keep up with the increased fuel flow with your mods. I say this because your engine did not quite, which is what usually happens with no transfer at all.
Thread Starter
Melting Slicks
Joined: Nov 2003
Posts: 2,213
Likes: 135
From: In front!
Left tank, which feeds the engine, should remain near full as the right tank empties. This can be checked by monitoring the tank sensor output voltages with a Tech II or a voltmeter.
It may be possible that the jet pump circuit which pumps from right to left is not conpletely inoperative but is obstructed in such a manner that it cannot keep up with the increased fuel flow with your mods. I say this because your engine did not quite, which is what usually happens with no transfer at all.
It may be possible that the jet pump circuit which pumps from right to left is not conpletely inoperative but is obstructed in such a manner that it cannot keep up with the increased fuel flow with your mods. I say this because your engine did not quite, which is what usually happens with no transfer at all.
