is 49psi at WOT with STS normal?
10-07-2008, 04:37 AM
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is 49psi at WOT with STS normal? well like the subject says, is it normal for fuel pressure to drop from ~57psi at cruising to 49-50psi at wot on about 6.5psi of boost?
When the turbo and racetronix setup were first installed fuel psi was at 62. three years and 25k miles later, it's anywhere from 57-59psi at idle to 49-50 at WOT. I just don't remember seeing the fuel pressure gauge dip like that before. I have run the gas down to check gauges like a couple of times including like a week ago after seafoaming the car. Oh should mention that I just changed the fuel filter today. I checked the harness connection on the batt. pos. terminal and it's nice and tight. I don't know quite where to start to diagnose the problem. I did post this in fueling & injection but didn't get any ideas and search isn't working. Is my pump going out?
When the turbo and racetronix setup were first installed fuel psi was at 62. three years and 25k miles later, it's anywhere from 57-59psi at idle to 49-50 at WOT. I just don't remember seeing the fuel pressure gauge dip like that before. I have run the gas down to check gauges like a couple of times including like a week ago after seafoaming the car. Oh should mention that I just changed the fuel filter today. I checked the harness connection on the batt. pos. terminal and it's nice and tight. I don't know quite where to start to diagnose the problem. I did post this in fueling & injection but didn't get any ideas and search isn't working. Is my pump going out?
10-07-2008, 04:43 AM
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No it is not, we normally see the fuel pressure drop to 54 psi at wide open throttle on systems such as yours, above 5000 rpm. I wouldn't go wot until you first make sure that the air/fuel ratio is still rich enough, as it may be running too lean.
You may have a pump going out, or the fuel line in the tank may be rubber and swelling up. We have seen this becoming a problem lately. Bob
You may have a pump going out, or the fuel line in the tank may be rubber and swelling up. We have seen this becoming a problem lately. Bob
10-07-2008, 04:49 AM
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yeah i usually keep my eye on the afr rather than the fuel pressure gauge. It's never gone higher than 11.4 and that's just at near redline. That AFR is high though because it used to not even register on the AEM wideband (lowest reading is 11.0).