99 Camaro SS need fuel system help.
07-05-2024 | 05:51 PM
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99 Camaro SS need fuel system help. Ok having fuel pressure problems with this pile. I bought it as a roller, and it already had a Delphi module with a racetronix 255. I swapped in a deashtwerks 340 pump when I added the turbo. It’s a 6.0 stock intake, stock lines with aftermarket rails. 7875 turbo, rear mounted, 80lb dekas, 14psi boost pump 93. Car is equipped with a Holley terminator X and fuel pressure as well as afr and closed loop correction and duty cycle are datalogged.
Started having problems with it losing fuel pressure under boost when the weather started getting hot (Alabama temps in the 90s). I thought the pump was failing due to the fact it was rocking 70psi at idle through the stock regulator setup. It originally would drop to about 52psi under boost, which didn’t worry me. But with warmer weather it started dropping dangerously low, and leaning out.
I purchased an aeromotive 340 (other car has an aeromotive pro series and has served me well) and the kit to change to the C5 style filer. Dropped the tank changed the pump and deleted regulator in the tank and swapped in the C5 regulator and the result is basically the same if not worse.
Next step was to swap to a boost reference regulator on the end of the rail, stock filter (yes it’s been changed Napa gold series filter USA made) and dropped the base pressure to 43 in an attempt to keep the pump cooler. No change.
Drove it until it got to 1/4 tank and verified problem was present before pulling into the gas station, added 10 gallons of fresh cool 93 and ran flawlessly leaving the gas station and all the way home.
Voltage is verified good (14.2v) at the relay, even while stressing the pump by cranking up the fuel pressure. Pump will make 100+ psi when called upon with minimum demand of flow, so it will make pressure, just not with flow. It has all original heat shields in place between turbo and fuel tank, turbo piping is wrapped, heat shield has space blanket between it and turbo, with an air gap.
The only thing I can come up with at this point is the fuel is getting too hot, making the pump too hot and it’s getting unhappy. I can make a few pulls and all is well, but after everything gets good and warm fuel pressure drops like a rock when it comes into boost.
Started having problems with it losing fuel pressure under boost when the weather started getting hot (Alabama temps in the 90s). I thought the pump was failing due to the fact it was rocking 70psi at idle through the stock regulator setup. It originally would drop to about 52psi under boost, which didn’t worry me. But with warmer weather it started dropping dangerously low, and leaning out.
I purchased an aeromotive 340 (other car has an aeromotive pro series and has served me well) and the kit to change to the C5 style filer. Dropped the tank changed the pump and deleted regulator in the tank and swapped in the C5 regulator and the result is basically the same if not worse.
Next step was to swap to a boost reference regulator on the end of the rail, stock filter (yes it’s been changed Napa gold series filter USA made) and dropped the base pressure to 43 in an attempt to keep the pump cooler. No change.
Drove it until it got to 1/4 tank and verified problem was present before pulling into the gas station, added 10 gallons of fresh cool 93 and ran flawlessly leaving the gas station and all the way home.
Voltage is verified good (14.2v) at the relay, even while stressing the pump by cranking up the fuel pressure. Pump will make 100+ psi when called upon with minimum demand of flow, so it will make pressure, just not with flow. It has all original heat shields in place between turbo and fuel tank, turbo piping is wrapped, heat shield has space blanket between it and turbo, with an air gap.
The only thing I can come up with at this point is the fuel is getting too hot, making the pump too hot and it’s getting unhappy. I can make a few pulls and all is well, but after everything gets good and warm fuel pressure drops like a rock when it comes into boost.