Tommy1995

OK so here is my situation if anybody can help. I have a 2008 base manual C6. Cam, v3 A&A supercharger (7 lbs of boost), ID1050 injectors, full exhaust, meth, tuned, ECS Stage 1 fuel system. Boost a pump. Lingenfelter hi flow pump.

The problem I'm having is a loss in fuel pressure. I have been told the car should be running 58psi. At start up the car runs at 58. As I'm driving around and it gets to normal opperation temp it will drop down to around 52. If I get stuck in traffic the car will drop lower and lower and eventually end up at around 42 to 45. Once moving again the pressure will come back up slowly to around 50. If after driving I shut the car off and let it sit for 15 minutes When I go back to started it will be low (around 48). It seems to me like the heat is causing the drop. But it also seems to me like it shouldn't even drop when it warms up to normal operating temperature and drop to 52psi considering all the extra stuff I have put on like the stage 1 fuel system and high flow pump with boost a pump. What could be causing the low pressure. I have a glowshift fuel gauge that is connected to the fuel rail. I have tried one other gauge
/sending unit to eliminate that as being the issue.

This all started after installing the A&A v3. Boost A pump was installed at the same time. Then the ECS Stage 1. No change in pressure. Hi flow pump. No change in pressure. Meth no change.

Any help please !

User Omega

Who installed the stage 1 system and BAP?

Tommy1995

BAP was installed by the LSX shop that did the blower. Stage 1 was installed by a shop i have used to do all my gas tank work. ie fuel vapor leak from top of tank/pump and high flow pump.

User Omega

I'm leaning towards your stock pump going bad.

Tommy1995

stock pump was removed and the hi flow Lingenfelter was put in. No change.

The order was...
Cam
Blower with injectors
Boost a pump
ECS Stage 1
Hi-flow fuel pump
Meth.
None of the above have had any affect on fuel pressure loss

User Omega

Have you checked the actual voltage at the pump?

Tommy1995

I haven't only because temperature seems to have to do with pressure loss. If the voltage wasn't there then wouldn't it always be low or start out at between 42-50?

Tommy1995

And would it be better to measure the voltage at the pump itself or coming out of the bap?

User Omega

You could test the output of the BAP too. With heat resistance increases. I am just giving you ideas.

Tommy1995

That is true. I will test the voltage coming out of the Bap. Thanks for the help

CI GS

More than likely it’s the stock fuel pump harness though, because neither the BAP or the ECS aux pump comes into play until youre making boost.
I would suggest replacing the stock FP harness with the Racetronix harness. That’s the best $60 anyone can spend on a C6, and the easiest install too. It even comes with the plug for your BAP. You just need to buy the plug to install on the power wire to the BAP and then it’s a completely plug and play deal.
BTW: why are you running a BAP with the Stage 1 fuel system? At 7 psi, you probably don’t need either, especially if you’re using meth. I would remove the BAP and just use the ECS fuel pump for fueling under boost.

Tommy1995

have a link?

Chiselchst

http://www.racetronix.biz/itemdesc.asp?ic=FPWH-008

http://www.racetronix.biz/itemdesc.asp?ic=IPH-008&Tp=

Tommy1995

great. Thanks !

DOUG @ ECS

Well said, I would also suggest putting manual pressure gauge on the car to know it's actually losing pressure, or is the sending unit failing.

BLWN427

I'd lean towards a voltage issue as well. I'd be willing to bet your charging system is at its peak voltage when the car is cold and alternator is cold. Which is supplying your fuel pump with the proper voltage. Then once the alternator is hot system voltage drops. Lowering the voltage to the pump...then in traffic the alternator heat soaks and drops voltage even more. ECT. I'd also recommend the upgraded harness as previously mentioned as well as you might want to look into a higher amp alternator depending on voltage readings when hot and idling.

BT03mach-1

Anything? I'm having kind of the same issue. ECS kit with just a BAP and hot wire kit. It will start up fine driving it around and make a few Highway hits and then it will start to stumble when taking off. it starts getting worse and worse and a/f gauge showing lean. when I get home it will not start. I bypassed the BAP and that didn't change. After awhile of checking wiring, solder joints, swapping relays, checking grounds and checking fuses it will start up again like nothing ever happened. I can jump the relay and hear the pump running. Voltage looked fine but when it started stumbling when taking off I stopped watching the voltage and watched the a/f

also when it starts doing this once I get it pass the stumble giving it gas it runs fine till you have to get off the gas. It's like it happens at light throttle then gets worse. My tuner said he didn't have any issues. IT seems to happen after driving for awhile

Tommy1995

Still nothing figured out on my end. All my tuners say the same thing that they don't have any issues. Yours definitely sounds like a vapor lock problem. Not sure if that's even possible in a c6 but it reminds me a lot of my old Camaro that had vapor lock. I will post any updates when I find out what's going on. Back in the shop this week for a clutch problem and feel pleasure/vapor problems

BT03mach-1

Thanks! I guess I can start searching vapor lock. The odd thing is after I installed everything the 1st start up it wouldn't start . I had jump the relay to make the pump run for it to finally start. So I'm wondering if its not a heat issue.

Tommy1995

I'm sure mine is heat related. Mine only had problem when warmed up. Always good pressure from a cold start.