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Raceghost - To answer your idle fuel pressure question, the standard fuel pressure at idle with the FPR vacuum line disconnected from the intake manifold is 43.5 psi. Don't try and set the fuel pressure with the vacuum line connected. I'll comment that the stock FPR is actually very good, and there is no need to upgrade unless you have a desire to run higher base fuel pressure than stock. For most people, there is no need to use anything other than the stock FPR.
MFred And Ace33Joe,
Thank you for the reply. I really appreciate it. I did find the thread on here about how to set an aftermarket FPR. My stock one was done, and this was one of the issues with my fueling issues thread. Originally yesterday it was set with vacuum line connected, and set to 43.5psi. Well it was erratic in reading on the gauge with in a matter of a few minutes, and it threw the trims completely out of wack. Turns out it was actually set at about 50 psi that way. Once I found the thread, I set it the way you discuss as well as the thread discusses, and trims are dialed in nice now.
Thanks again.
sorry to bump an old thread but I am looking to possibly do this to take advantage of running e85 soon. I am really interested in keeping the high/low voltage function. I'm currently on FIC1100's and a walbro 255 but plan on upgrading later with the motor build.
So which of the methods listed here is the most reliable and hopefully the least intrusive (i.e. not chopping up the stock wiring). I was almost convinced to do the method i have uploaded the attachment for but reading through this I read something about the diodes possibly failing??
sorry to bump an old thread but I am looking to possibly do this to take advantage of running e85 soon. I am really interested in keeping the high/low voltage function. I'm currently on FIC1100's and a walbro 255 but plan on upgrading later with the motor build.
So which of the methods listed here is the most reliable and hopefully the least intrusive (i.e. not chopping up the stock wiring). I was almost convinced to do the method i have uploaded the attachment for but reading through this I read something about the diodes possibly failing??
any advice from folks that have done the mod?
Diodes aren't ideal for this because they create a voltage drop across them. So thats less volts to the pump, and the voltage drop turns into heat. So the diode will get really hot. The easiest and IMO best approach for most will be to use a relay connected from to the battery and spliced in or connected to the factory wiring at the pump connector. Then you trigger that relay off of a hobbs switch. This way you keep all the factory wiring and systems in tact, and you are adding more copper to the factory system instead of replacing whats there with something a little bigger. You end up with a lot more copper this way.
Diodes aren't ideal for this because they create a voltage drop across them. So thats less volts to the pump, and the voltage drop turns into heat. So the diode will get really hot. The easiest and IMO best approach for most will be to use a relay connected from to the battery and spliced in or connected to the factory wiring at the pump connector. Then you trigger that relay off of a hobbs switch. This way you keep all the factory wiring and systems in tact, and you are adding more copper to the factory system instead of replacing whats there with something a little bigger. You end up with a lot more copper this way.
thanks for the reply! looks like i'll be ordering a STM rewire kit and hobbs switch.
Jun 3, 2016, 03:13 PM
& thanks a load
