Fuel starvation when maxing out? |
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Fuel starvation when maxing out? |
David Stowers |
Feb 10 2014, 07:01 AM
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#1
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Member Group: Members Posts: 99 Joined: 28-June 12 From: UK Member No.: 14,613 Region Association: None |
My 914 is running a 1.8 (ish!) 40 Dellortos and recently recorded 111BHP and 121lbft of torque after a carb set up so yesterday I went to have a little thrash about.
A couple of times when the traffic cleared I really kept my foot flat down and pushed to over 100MPH on a slight uphill. It was still pulling strongly for a few seconds then seemed to lose power and splutter slightly. I backed off and it returned to normal. It seemed like the carbs emptied as if the fuel pump couldn't keep up. I had the heater on and the rich oily aroma changed to a hot sharp smell like it suddenly ran lean. It's running the small square facet pump mounted up front near the master cylinder. Any ideas please Thanks David |
ThePaintedMan |
Feb 10 2014, 12:41 PM
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#2
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Advanced Member Group: Members Posts: 3,886 Joined: 6-September 11 From: St. Petersburg, FL Member No.: 13,527 Region Association: South East States |
Facet pumps, while cheap, are typically viewed as inadequate/unreliable with carbs for these cars. A Carter or similar style rotary pump is preferred as they provide a constant volume of fuel at an adequate pressure. CB Performance over here in the U.S. sells one such pump: http://www.cbperformance.com/ProductDetail...roductCode=3193
This pump is self-regulated at 3 1/2 PSI, which is perfect for DRLAs or most Webers and eliminates the need for a pressure regulator. I would start there and see if that clears up your issue. From what you're describing, it does sound somewhat like fuel starvation. That being said, go through the normal (read: FREE) checks first. Check/set your valve clearance, verify timing and check to ensure that the carbs are synched at both idle and 3,000 RPMs. Then, when you have the time and money, replace the Facet pump to eliminate variables. |
David Stowers |
Feb 10 2014, 12:56 PM
Post
#3
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Member Group: Members Posts: 99 Joined: 28-June 12 From: UK Member No.: 14,613 Region Association: None |
Facet pumps, while cheap, are typically viewed as inadequate/unreliable with carbs for these cars. A Carter or similar style rotary pump is preferred as they provide a constant volume of fuel at an adequate pressure. CB Performance over here in the U.S. sells one such pump: http://www.cbperformance.com/ProductDetail...roductCode=3193 This pump is self-regulated at 3 1/2 PSI, which is perfect for DRLAs or most Webers and eliminates the need for a pressure regulator. I would start there and see if that clears up your issue. From what you're describing, it does sound somewhat like fuel starvation. That being said, go through the normal (read: FREE) checks first. Check/set your valve clearance, verify timing and check to ensure that the carbs are synched at both idle and 3,000 RPMs. Then, when you have the time and money, replace the Facet pump to eliminate variables. Sounds like a sensible and affordable plan, Thanks |
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