Fuel Pressure question (afpr)

[GSX26]

Alright, here's my problem, or question rather. I have been searching around for the answer with no real luck, so please don't flame and say "search". I know the base fuel pressure is 43.5, however is that at idle, under boost, or all the time it should be at that? Because I have my afpr hooked up and at idle it's like 40 psi, and then under boost it rocketsd up to 60...normal? Or maybe the afpr is broke or hooked up incorrectly? Or should I try to get the 43.5 psi set for under boost conditions? Thanks

 

[EclipseTrbo420A]

Alright, here's my problem, or question rather. I have been searching around for the answer with no real luck, so please don't flame and say "search". I know the base fuel pressure is 43.5, however is that at idle, under boost, or all the time it should be at that? Because I have my afpr hooked up and at idle it's like 40 psi, and then under boost it rocketsd up to 60...normal? Or maybe the afpr is broke or hooked up incorrectly? Or should I try to get the 43.5 psi set for under boost conditions? Thanks

No your ok , just set it at idle with the car warmed up to 43 lbs...then with every one pound of boost your car makes it will raise fuel pressure 1 psi . Get it ? your set up is fine just set it at idle to 43 lbs.

Its a 1:1 ratio so 43 lbs at idle then 17 lbs of boost = 60 lbs of fuel pressure at 17 lbs of boost.

 

[weith1111]

Your FP readings need to be taken at idle, with the vacuum line to the AFPR off. Having the vacuum line on will make your FP change according to whatever vacuum you are pulling divided by 3, roughly. AKA not accurate, so take the line off.

And fyi, during boost the FP will be raising 1psi per psi of boost. That's how the system is designed. But anyway, yeah do it at idle. If your idle is messed up (1500 rpm), get that fixed first, you want it steady at 7-900 to get a good reading.

Good luck.

 

[spoolup]

also besure to cap the vacuum line you removed with your finger or slimilar your car may run funny/ stall when attempting to change FP.

 

[GSX26]

Thanks for the help and reassurance guys! So when I tune with dsmlink, I should use my fp of 43.5 to figure out my fuel settings? Or do I use the higher FP when adjusting my fuel trims once boost hits? Thanks again guys!

 

[WFO-TSi]

According to the injectors you are using in your profile you will want to set your "global" at -38% and your "dead time" at 450 micro sec. Those suggested settings are as per the instruction manual for running a base fuel pressure of 43.5psi. Personally my car didn’t run optimally when set according to the suggested settings in the instruction manual.

To get back to your question, when setting up your fuel trims with Dsmlink you do so based off of the base fuel pressure you are running.

 

[spoolup]

Just out of curiosity GSX26, did you get your problem resolved and FP figured out? And where did you mount the AFPR?

Also I assume you are using the FP port on the AFPR right?