fuel pressure dropping please help
 

Hey guys I'm having fuel pressure issues. New, isr fpr, aem 340lph fuel pump,300zx fuel filter, new 72ilb Jim Wolf top feed injectors.

Fuel pressure will be at 38 psi w vaccume but after 10 minites of driving it drops to 20psi. I checked voltage to the pump and I'm @ 13.4v no vac leaks, tested fuel pump, no fuel leaks anywhere

make sure you have a good ground to the fuel pump. the pump could be struggling with good voltage and a bad ground, heating up after 10 minutes of driving, and then slowing down.

Upgrade your wiring from the factory 18-20gauge to something a little more substantial.

Also, get rid of the knock-off FPR and invest in a quality piece.

hey guys thanks for the help ill try that when i get home. i forgot to mention my fuel pump is hardwired and on a relay i thought it could be the relay so i swapped that as well

would injector being stuck open cause something like this?

It could, but then it would run rough, puke black smoke like a diesel and ultimately wash down that cylinders walls. His oil would smell strongly of fuel too.

Hey guys thanks for the advice no luck but swapped the fuel filter and a bunch of rust looking stuff came out pulled the injectors out and had the same. Might need to drop the tank and clean it out anyone in Houston that’s willing to help

just run the pump to get the fuel into a container and drop it, easy peasy!

that wont get all the gunk and grime out of the bottom of the tank. I've seen fuel socks that were so clogged up they would barely flow, causing the pump to overheat. remove the sock and drop the tank into a bucket with clean fuel and it would flow just fine!

also, I agree that a injector sticking open or a injector o-ring that is leaking, could also cause a fuel pressure drop, but it would def be running rich as fuck

negative...just do that to get fuel out then the tank doesn't have fuel and weighs next to nothing...last 3 fuel pumps i have done on SUVs the tanks were full and its a lot heavier lol! then you don't waste the fuel, can use it for cleaning or whatever and with the tank out you can wash it...don't use water tho!!!!!

Anyone have a good suggestion for something to use to clean out a fuel tank? My spare is all full of dirt and crap :( I tried to get it acid dipped locally at a radiator shop, but the EPA put a stop to them having the acid dip tanks that they used to use.

i have had good luck with lacquer thinner and washer bin solvent...just takes about forever...i would spray out as much as i could with water then go to town with the others before more surface rust starts

Acetone should do the trick.

I've always been curious about eastwoods fuel tank cleaner kit. be the test dummy.

https://www.eastwood.com/gas-tank-se...nk-sealer.html#