Quote:
Originally Posted by Harrychiu012
With 29E2 and 29F2.. does it mean the LPFP and HPFP will need to be replaced soon?
Also, will getting a fuel it inline or stage 2 bump help remedy this situation?
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The codes don't necessarily mean your fuel pump is failing. When are you getting the codes to come on? Are you getting the half engine light (limp mode) ?
What kind of gas are you using? If you use gas that has a high ethanol content it may be the root of the issue.
The problem with ethanol lies in stoichiometry. Pure ethanol has a stoichiometric AFR of 9:1 whereas regular gasoline has an AFR of 14.7:1.
In other words (correct me if I'm wrong) you need 14.7 units of mass of air for one unit of mass of gas, 1 gram of gasoline burns with 14.7 grams of air.
For ethanol, you can burn less air with the same amount (9 parts air for one part pure ethanol). Naturally, the engine has to compensate by adding MORE fuel for each ignition cycle.
In our situation this translates into more work for a fuel pump which is being already used above standard specifications (if you have JB4 or any other tuner). At some point, the fuel pump cannot sufficiently increase the pressure to obtain the correct amount of gas injected for each cycle and you get a fuel pressure error.
JB4 works by tricking the car's computer into thinking the fuel pressure is lower than it actually is to get it to increase it to what the computer thinks is a "normal" level. If the fuel pressure increase necessary is too great, it causes the computer to think the pressure is WAY too low for normal operating conditions and you get your error code and limp mode.
Therefore, try to keep to zero ethanol gas.