i've seen pics of people mounting a fuel pressure gauge in the fuel line BEFORE the vafpr on the throttle body.

how can you get an accurate reading of the fuel pressure adjustments you make?

as i understand it, you'd only get a reading of the fuel pressure between the fuel pump and the vafpr, not the adjusted pressure AFTER the vafpr, right?

can anyone help?

thanks

 

It's rather hard to see if from just looking at it but here is how the system works. Fuel starts in the tank, goes into the pump, goes through the filter up the supply line, then straight into the injectors, THEN the AFPR, into the return line and back into the tank. The injectors are between the pump and the AFPR, not after. This is why you can tap into anywhere on the supply line to get your FP at the injectors.

 

jon,

so where is the ideal mounting position for a fuel pressure gauge?

also, i've been reading about a program you wrote to automatically adjust fuel tables.

i'm having a hard time getting my arms around datalogging / chip burning. can you help?

thanks,

 

Just mount the gauge inline with the top flex line. This placement keeps it away from engine heat and will give you a good reading. Just keep in mind that those cheap $20 0-30psi gauges are very sensitive to temp change. You can hold one in your hand and watch the needle move! So when you look at the pressure, just record what the underhood temp was, this way you aren't faking yourself out every time you look at the gauge and it's different.
The program I wrote was bassed on somebody elses script. I just made it work, lol, and it supports both the 7747 and 8746 ($42 and $61 BCC). Do a search for Aldl to bin or make it one word, I forget. I know it just resurfaced the other day. It takes winaldl data and a bin, then spits out a new bin with corrected VE. It likes as much data as possible so don't go romping around with a lead foot or you'll end up with junky VE tables.

 

yeah, i have mine in the supply line...

-brian