50 PSI of Fuel Pressure, Can this be right?

[Cooker]

Here is how I tested: TST Adapter (for testing on top of filter housing), 3ft 1/4" 300psi Goodyear hose, 1 1/2" liquid filled 60psi gauge from Grainger.

I just put a frsh filter on my '96 (I did not use the 1253 filter, but the upgraded, larger 19519 (I think that is the number)).

The reading I got was 49 - 50 psi at idle, and when I ran the motor up to 1600-1800 rpm the reading went to 45-46psi.

Can this be correct. Am I doing something wrong? The truck is stock except for some minor "tweaking" the previous owner had done right at Cummins Michigan.

Your comments would be much appreciated. Thanks for the help,
Ryan

 

[illflem]

Ryan, I would find it very hard to believe that your new pressure gauge would be off that much. The way you are hooked up is right, the reading is correct. Is the gauge pulsing?
I would think that a reading that high is something other than an overflow valve problem, maybe a kinked or melted return line? If you kink or compress the return line with pliers the reading should go up, but I'll bet it doesn't, that's probably the max psi the lift pump can put out. You might also try disconnecting the return line at the tank, put the hose in a container and see if there is any return, work your way back from there.

 

[DHRA]

I have had 45 psi for over a year now, no problems, other than the back tires not hooking up all of the time #ad

 

[SlyBones]

Happen to have the PN for that grainger gauge? Just went there and they have a ton of gauges. The link in here is still broken.

The gauge has 1/4" inlet? Seems like read the TST adapter is 1/8" outlet. How did you adapt it?

Thanks.

-----How does this sound -----

Liquid Filled Gauge, 1 1/2 Inches Dial, 1/8 Inch NPT, Center Back Mount, 0 to 60 PSI
Made by WESTWARD
item# 5WZ17

-or-

Economical Liquid Filled Gauge, 1-1/2 inch Dial, 1/8 inch NPT Center Back Mount Connected, 60 psi Pressure Range
Made by US GAUGE
item# 5HK52

Both $7-$8 range.

[This message has been edited by SlyBones (edited 04-04-2001). ]

 

[illflem]

SlyBones, either one will work fine.

 

[Cooker]

Grainger part number for 0-60lb, 1 1/2", liquid filled, 1/8" NPT center (male) outlet $7. 96 + s/h

Part# 5HK52

Ryan

 

[illflem]

Maybe it's only if you have an account with Grainger, but if you order over the internet shipping and handling are free.

Ryan, forgot to mention that I've seen my mechanical gauge read as much as 20 psi high when the temperature is below freezing, but when it happens it doesn't zero also. The colder it is the more off it becomes. I was assumeing that your outside temps were warming as mine are, but could be wrong.



[This message has been edited by illflem (edited 04-05-2001). ]

 

[Cooker]

I haven't found the source to the high fule pressure yet, but when I tear into it I'd like to have an overflow valve on hand (just in case it is defective).

Where is the best, or cheapest place rather, to get a overflow valve, dealer or Cummins. How much should I figure on spending.

Thanks, Ryan

 

[Joseph Donnelly]

I use several feet of 1/8" plastic line like for oil pressure or boost gauges, and whatever gauge I have handy, like a boost gauge. Spec is 17-22 lb at idle, 25-30 at "rated speed" or around 2500 rpm. There shouldn't be any need for you to go much if any beyond that. If you have the late (aorund 95-up) style overflow valve, remove the cap carefully and remove a shim or two from the stud under the cap to decrease pressure. Be careful and you can do it with the rest of the valve on the truck.