99 & up 7.3L Power Stroke Engine and DrivetrainDiscussion of the 99 & up 7.3L Power Stroke diesel engine and drivetrain in the 1999-Up Super Duty trucks and Excursions. No gas engine discussion allowed except on transmissions and drivetrain that pertain to all models. Please confine discussion of topics in this forum to those items that are specific to the 7.3L Power Stroke engine.
I have a 1999 7.3 Powerstroke F250. I'm not a super experienced diesel guy, so I'm not claiming that this is the best way to check fuel pressure, but it worked for me so I thought i would share it.
I didn't want to cut into my fuel system so I connected a hose -- the blue hose in the pictures -- (about 3 foot of 3/8 high pressure hose) to the fuel filter purge tube. The purge tube can be found by looking behind passenger front tire, you can see a tube that just hangs down. When you flip the yellow switch behind the fuel filter assembly, the fuel dumps down this tube.
First of all, having a hose there is a good idea so you can catch fuel when you purge the bowl. Second, it is a handy place to check pressure.
So I went to Home Depot and got a pressure gauge for 8 bucks, a couple of brass fittings to adapt to 3/8 hose, and some hose clamps. Also I used the goop that you put on these connections to keep them air tight -- I think it's called thread sealant.
I turned on the truck with this assembly all hooked up, and when I was ready I opened the purge valve on the fuel filter assembly. At first there was no pressure reading but over the next minute or so I watched it climb to 60 PSI. I suspect that the pressure was negligible at the beginning because there was air in the lines and it took a few secs to build up the pressure and spread it out.
When I was done I left the hose connected for future use, but i used zip ties to keep it out of the way.
Does this sound like an accurate reading? I'm about to check my fuel pressure, and I need to spend as little as possible, and this seems to be a quick and easy method. Is the reading responsive enough to pick up on changes when revving? Thanks, guys.
1999.5 Ford F-250 7.3L - 208K miles CCSB
Airaid Stage 1 Intake / Muffler Delete
TS 6-Position Chip (stock burns)
305x70x16 Terra's on 16x8 Vision Wheels
The downside of that method is that the metal tube is connected to the drain valve with a rubber hose section with no clamps. If it blows off while you're testing you'll have a valley full of fuel.
The positive way to check fuel pressure is to use one of the boss o-ring plugs on the back of the filter housing, adapting to a hose fitting and gauge. You do have to drain the fuel bowl to make the connection, but at least that won't fill up the valley with fuel.
The hose on the drain is a good idea, though, because you can use it when draining the filter to catch the fuel instead of dumping it on your front axle housing.
Getting fuel or oil in the valley is one thing, but getting fuel sprayed into the airbox of the environment controls is another. You will never get that smell out, and you will smell like diesel every time you drive it.
I would make sure the nipple on the drain valve is cleaned and put a hose clamp on it.
99.5 PS CC 4x4 SRW ZF-6
Triple Pillar Gauges; Fuel pres, Pyro, Boost
AE, Alldatadiy, and half a clue
- AKA "The Big White Truck"
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