Is my rail pressure gague broken???

[Toshiro]

Is my rail pressure gague broken???(Updated)

After I installed a rail pressure gauge the typical reading were as follows:



Idle = approx 7000 psi

WOT acceleration = 24000 psi max and settled out to approx 20000 psi

WOT with predator box on 100hp = 26500 and hold there until hwy speed...



Now it reads differently,... ... ... sometimes



Idle = 10500psi

WOT no box = 27000

WOT with box on 100hp 30000 plus... that's right, I can bury the needle and hold it there... .



When the gauge begins to read the higher numbers I can shut the truck off and turn it back on and all is normal again for a while... . A little later when I look down at the gauge it is reading high again... .



I thought that the max the gague could read from the truck was 26500...

Is the gague not working properly?

Could the gague be correct(sure hope not. . lol)?



This sure has me puzzled... any insight would be appreciated... .



Thanks

Toshiro

 

[JCleary]

I would check the connections, perhaps use some dielectric grease.



I periodically have surging issues caused by my pressure boxes. I will apply some dielectric grease (Permatex) and the surging will go away. Bad connections will cause strange symptoms.

 

[Mark Craig]

Toshiro,



Remove your performance boxes and see if it remains constant on a stock truck. Lots of brands will vary due to lots of variables that you would not normally see/feel etc. We've sold a lot of them and so far zero problems to date!



Mark @ DPPI

 

[Diesel Power]

let us know if the problem continues, we will take care of it. thanks

 

[TCDiesel]

It's Dr P. . Have you owned the truck since new,It certainly looks like some type of downloader Program IN ECM.

 

[Toshiro]

I have owned it since new (July '05).



Diesel Performance, thanks for remembering me and offering to take care of me... I really appreciate it... I will try the suggestions mentioned before replacing it... it is probably the box doing it... .



I will disconnect the box and apply some dielectric grease and see if the readings ever get weird again... .



I'll report back in a few days.

Thanks guys

Toshiro

 

[Toshiro]

OK, I applied the grease and checked the fittings and then did some running around today trying to figure out what was going on and this is what I found... .



Start the truck and run around with box removed from truck:

- gauge reads what it normally does, I could not make it read high no matter how hard I got on it.....



Install box but leave it in the off position:

- gauge read a little bit higher across the board except at idle(approx 2000psi)



Turn box on 100hp and give 'er hell:

- gauge reads normal for a bit but then after a few romps it would read high as stated above. Gauge would not return to 'normal' until I shut the truck off and restart, then all was normal again until I turned the box back on for a bit...



... so it seems that Good 'ol Dr. P is causing the issue... That leaves me with 2 questions. .



?Is the gauge telling me the true pressures? Are they really getting to 30000psi?!!



?Why would the gauge read a little higher just by plugging in the box? Are they really higher or is the box just messing with the gauge?



... one last interesting thing, my turbo gauge acts up too. With the box completely off my truck I hit about 27psi and settle out to 23psi or so... . when I plug in the box but leave it turned off I can hold 33 to 34 psi... hmmm. . the box must be doing something even when it is turned off... maybe I'm just crazy...



Thanks Again for your input guys... .

Toshiro

 

[MMeier]

Just put 2400 miles on mine in 42 hours... after a lenghty haul on the hiway, mine would hang out around 10-12k at idle, when i shut truck off and restart , all is "normal" again,checked all connections, all good, gauge issue or... ?

 

[Diesel Power]

the boost fooling is changing your rail pressure, when just plugged in it also boost fools as not to set a over boost code, the 30000 is confusing because th emost the sensor is capable of reading i thought was 27k max---because it reads voltage with a max of 5 volts and that is 26500-27000.

 

[JCleary]

If you have a mechanical boost gauge and it's reading 10psi high, you can be sure the box is still fueling when turned off. If you have a boost gauge pulling a signal from the MAP sensor, I bet the SP box is throwing both the rail and boost signals off.



Ditch that SP box and get yourself a TS MP-8. It's really a great pressure box, and they also have a stack-specific program if that's what your intentions are.

 

[Lightman]

Just put 2400 miles on mine in 42 hours... after a lenghty haul on the hiway, mine would hang out around 10-12k at idle, when i shut truck off and restart , all is "normal" again,checked all connections, all good, gauge issue or... ?

what pressure do you see driving down the road on the flat at 8-10 lbs of boost

 

[mcsinfl]

Not to steal a thread, but can someone tell me who makes rail pressure gauges?

 

[MMeier]

what pressure do you see cursing down the road on the flat at 8-10 lbs of boost

Lance, was noticing around 16-19k steady cruise. Lets see whats up this weekend, maybe you can ride along and see what you think! I need to call you as it is, didn't see you at the track Saturday night.

 

[Toshiro]

Ditch that SP box and get yourself a TS MP-8. It's really a great pressure box, and they also have a stack-specific program if that's what your intentions are.

... . Tell me more. . SP? TSMP8?. . Im not sure what that means... but you have my interest ... my boost is a mechanical gauge so your probably right... . thanks

 

[Toshiro]

the 30000 is confusing because th emost the sensor is capable of reading i thought was 27k max---because it reads voltage with a max of 5 volts and that is 26500-27000.

... . That's what I thought too, but all I can say is the needle gets to 30000psi pretty easily... . lol

what pressure do you see cursing down the road on the flat at 8-10 lbs of boost

... My pressure cruising is similar to MMeier's approx 15-20k psi... . the slightest blip of the go pedal will make it dance in that range...

Not to steal a thread, but can someone tell me who makes rail pressure gauges?

... PM Diesel Power... he was a pleasure to deal with to get my gauge...

 

[MCummings]

... cursing down the road...

Sometimes traffic can get really bad here in texas too...



Merrick

 

[DLeno]

Toshiro do you have any other radios, radar detectors, or other after market electronics installed in your truck?

 

[JCleary]

... . Tell me more. . SP? TSMP8?. . Im not sure what that means... but you have my interest ... my boost is a mechanical gauge so your probably right... . thanks

TS Performance MP-8, also known as the Ramifier. The same box will work on 8 different diesels, including the Liberty Diesel, providing you have the proper harness. It's really nice as it's infinitely adjustable. No detents to lock in a certain horsepower level or rail pressure boost.



I had a problem with a pressure box that kept fueling, even when set to "off" so it is possible your pressure box is causing the problem.

 

[Diesel Power]

TS Performance MP-8, also known as the Ramifier. The same box will work on 8 different diesels, including the Liberty Diesel, providing you have the proper harness. It's really nice as it's infinitely adjustable. No detents to lock in a certain horsepower level or rail pressure boost.



I had a problem with a pressure box that kept fueling, even when set to "off" so it is possible your pressure box is causing the problem.

that is very true, anything is possible with todays electronics.

 

[Toshiro]

Toshiro do you have any other radios, radar detectors, or other after market electronics installed in your truck?

No other electronics in the truck. The only thing that might be close is 4 light force lights, but the symptoms happen with them on or off. The only thing non-stock about the truck is gauges, exhaust, intake, 35"tires, lights and the pressure box.