fpr mod just did it need an opinion

[melmount]

I just uses a small screw with the end cut off. The head fit nicely in the spot. Its less then a nickel in thickness which is .060
i digure about 45 to 50 thousandths.
i had 60 psi to startand now have 75. I used an oil pressure gauge by autometer for the reading. i figured fuel is an oil. I only used it for 5 minutes.
Can i leave it like it is til next week when i test with a different gauge? Will 75 psi explode anything? Digured i would drive it a day or two to see if a difference before i reduce it?
any imput?
thx
ps whats the thread size of the plug we hook a gauge to? the torx near the fpr? Its got an O-ring on it?

 

[DaveBen]

75 won't blow up the gauge, but fuel inside of the truck is dangerous. The line can blow and you will have a smelly mess, at best; or a fire...

Dave

 

[melmount]

i took the gauge off. I just used it to see where i was at to start. I am going to buy a gauge next week when i get paid.Can i leave it at 75 or is that bad for the truck?
being an oil gauge it may be off. I doubt it its a nice autometer. I will do a oil gauge andmount it nder hood next week. WillI be ok at 75 psi motor wise? As long as it runs better and not rough?
thx

 

[Tail_Gunner]

70 to 75 I think is about the high end of the range to shoot for for shimming the FPR.

As far as a gauge goes, you can either use an ELECTRIC FUEL PRESSURE GAUGE or a Mechanical fuel pressure gauge. If you use a mechanical one and mount it inside the cab, just make sure you use a FUEL PRESSURE ISOLATOR.

FWIW: Under hood gauges are nice for measuring fuel pressure at idle with the hood up. When my fuel pump died, it's idle pressure was fine. But when I was towing the work trailer down the highway and stomped on it to pass, the fuel pressure would drop off to about 10psi. When I took my foot off it would rebound to about 40 psi. At a stationary idle it was about 60 to 65 psi. The only way to detect something lke that is to have an in-cab fuel pressure gauge.

 

[melmount]

cool thanks, i have stainless hose for the gauge. @ pieces in fact. Just need th isolator. Right now itsmounted under the hood. What is the fitting size that replaces the torx fitting on the back of the fuelfilter? Right now to test pressure i use the drain line. I open it to see fuelpressure then shut it off.

 

[BIG JOE]

I just uses a small screw with the end cut off. The head fit nicely in the spot.

** There's an orifice on the end of the brass sleeve (where the shim is now) that bleeds off FP at shutdown. You might wana drill a hole in the screw head you used.

i had 60 psi to startand now have 75.

** a tad high but prolly won't hurt anything. 65-70 @ idle is IH preferred.

I used an oil pressure gauge by autometer for the reading. i figured fuel is an oil. I only used it for 5 minutes.

** I'd recheck the psi when you get the Fuel Pressure gauge.

Can i leave it like it is til next week when i test with a different gauge? Will 75psi explode anything? Digured i would drive it a day or two to see if a difference before i reduce it?
any imput?thx

With 75 psi, and the orifice possibly blocked.. you may end up with fuel sloowly bleeding off into other places in the system..... after shut-down.

Yer call tho..

Joe

Just an opinion ?

 

[melmount]

it could, i guess. I dont know where it would go? thru injector?
It seems to run smoother. But wont know til a few days of driving. will keep the post updated. If 70 is a good number, I am not far off. What did you mean orifice blocked?? what blocked?
It foes not stay at 75 after shut off. Goes right fown as it supoosed to

 

[BIG JOE]

it could, i guess. I dont know where it would go? thru injector?
It seems to run smoother. But wont know til a few days of driving. will keep the post updated. If 70 is a good number, I am not far off. What did you mean orifice blocked?? what blocked?
It foes not stay at 75 after shut off. Goes right fown as it supoosed to

If the pressure falls off at shut down, yer good to go.

There's a very small orifice in the center/bottom of the brass sleeve. Engine running, it's moot. when you shut down.. the FP bleeds to 0... thru it. It's also to prevent spikes from throttle inputs.... gets Rockety Sciencey from there.... but it shouldn't be restricted. JMO I guess, but that's the reason I stay with.. using the washers.

IH sez 65/70, psi, FP. Sooo I always stay with that. It's a "More is Not Better".... Sometimes....(?)

Joe