Fuel Pressure
#1
Racer
Thread Starter
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On my new to me 89 Turbo it came with a LR Adjustable FPR, fuel rail pressure gauge, LR Chip set all circa 2006. The rail gauge reads 40 psi warm idle with FPR vacuum line attached. Car runs very well AFR's on 17 psi WOT read slightly rich low 11's. Is the 40 psi at warm idle a typical +/- good number?
#4
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Which FPR is it? With the line disconnected you should adjust pressure for whatever the car is set up to run. Factory was 2.5 bar, and a common practice is to up pressure to 3bar to cover most moderate tunes. IDK what your car is set up to run, so don't take this as literal changes to make.
Last edited by Darwantae951; 07-12-2021 at 02:05 PM.
#5
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On my new to me 89 Turbo it came with a LR Adjustable FPR, fuel rail pressure gauge, LR Chip set all circa 2006. The rail gauge reads 40 psi warm idle with FPR vacuum line attached. Car runs very well AFR's on 17 psi WOT read slightly rich low 11's. Is the 40 psi at warm idle a typical +/- good number?
#6
Racer
Thread Starter
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Yes, stock air meter and injectors. Chip set requires either 3 Bar or Adjustable FPR. My rail gauge is at 40 psi warm idle with vacuum line on Adjustable FPR. Dave at LR feels low 11's is a little Fat, he prefers to see 11.6, suggested reducing fuel press. slightly (2 psi) and check the AFR's. What I didn't confirm was, and if it's necessary, to make the adjustment with the vacuum line attached or not?
#7
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Yes, stock air meter and injectors. Chip set requires either 3 Bar or Adjustable FPR. My rail gauge is at 40 psi warm idle with vacuum line on Adjustable FPR. Dave at LR feels low 11's is a little Fat, he prefers to see 11.6, suggested reducing fuel press. slightly (2 psi) and check the AFR's. What I didn't confirm was, and if it's necessary, to make the adjustment with the vacuum line attached or not?
Last edited by Darwantae951; 07-12-2021 at 10:03 PM.
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#8
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I just adjusted as per instruction. Warm idle vacuum line disconnected and pinched, gauge went from 40 to 46. Adjusted to 44. Now with vacuum gauge reads 38. Will do some cautious AFR testing tomorrow. Is 40 to 46 typical? The other thing I'm curious about is after turning off the engine the gauge went up to a hair above 40. Normal??
#9