Fuel pressure

[Steves LX]

Can anyone tell me what the correct way is too adjust fuel pressure with an afpr. I have heard you need to pull the vacum line off the regulator and plug the line off and then adjust it to whatever you want and I have heard that you leave the vacum line on and do it. I adjusted mine with vacum line off and my thumb over it. I hope I have been doing this right. Something that I have noticed is for ex. I put it to 40 psi. Now as soon as I hook the vacum back up to it the guage reads 32-35 psi. If I rev it up the guage will jump up to around 38 or so and then drop back down to 32-35. Is this normal or what?

[Stangman]

I know your car and my car are two completely different animals, but my car runs at 40psi at all times, very rarely does it drop below 38 or so while running, if at all.

Of course your fuel pressure spikes when you snap the throttle, because your computer tells it to, and the vacuum sucks on the FPR, so it can meet the demand of the injectors for a snap rev. My car does it too, but not as drastically, and only for a quick second, just like yours does, although your car jumps higher because of upgraded fuel delivery on your car compared to my stock junk.

I think you are thinking too far into it. ;)

But as for adjusting the FPR, I have no idea, I've never had to do it. Heck I've always watched you do yours and assumed it was the right way :lol:

[kennebellcobra]

You should unhook the vacume line...if it is hooked up when your idle changes so will your fuel pressure.

Yes it is normal to drop with vacume.