look at my rail pressure

i would question that also, whats the check engine light on for. what code.
 
PO148. I know what the code is and have been trouble shooting it for about two weeks. I had access to a star scan yesterday and everything checked out just fine. Set points, sensors, etc... This happened after I installed new 90horse injectors. The last thing I need to do is a flow return test and install new connector tubes before I can finally say it is the injectors.
 
I have seen bad injector bodies cause this problem. But first check your fuel tube nut to make sure it has not worked a little loose.
 
Well, could be a bad FCA, or your gauge could be messed up.
 
call john at floor it to see what he thinks on his end(the pump)
 
gauge is fine, it was right in line with the star scan. all sensors are fine per the star scan. John is a tough man to get a hold of but i did leave him a message about this thread. Im just tired of throwing money at this truck trying to find the problem.
 
Kinda hard to tell but were the rpm's going up with the increase in RP?I know on the beta 4.2 tune it has elevated RP at idle,in the 9k range and it also causes the idle to be higher,around 900rpm.It didn't look as though your idle was going up that high.I would guess some fuel is leaking by,whether its the tubes or an injector and the RP is fluctuating trying to maintain a constant level.
 
The rpm was staying in place. When the rp would fluxuate the rpm's would not move. I did put a rail cap on last night and it seemed to of help steady the rp just a little but not enough to fix the problem.
 
john will fix you up hes a stand up guy and yes he is hard to get ahold of but his products are top notch!
 
Do you have access to another rail pressure sensor? Mine did something just like that and it ended up being the sensor. 5 minutes and fixed.

However, it has done something like that on my wifes truck as well. It has a stage 2 floor-it cp3 with a Pricol rail gauge, and the gauge starts acting funny once in a while. I have heard the Pricol gauges (I think fixed now) had issues with a modded CP3. But I imagine it does this everytime you fire it up right?

My money goes to bad sensor, or bad fca.
 
white97gtvert said:
Do you have access to another rail pressure sensor? Mine did something just like that and it ended up being the sensor. 5 minutes and fixed.

However, it has done something like that on my wifes truck as well. It has a stage 2 floor-it cp3 with a Pricol rail gauge, and the gauge starts acting funny once in a while. I have heard the Pricol gauges (I think fixed now) had issues with a modded CP3. But I imagine it does this everytime you fire it up right?

My money goes to bad sensor, or bad fca.
Click to expand...

X2
If it starts good than its the RP sensor,if the FCA was bad it would effect RPMs and starting.
 
i have the old rp sensor that i took to be replaced with this new rp sensor. what is the chance of two bad sensors? like i stated before all sensors checked out fine with the starscan
 
Your video shows exactly what mine was doing, wildly flluctuating rail pressure and the P0148. I had about a 150 mile trip last week and it was doing it at the beginning of the trip and got progressively worse as the trip went on and the truck actually died driving down the highway at 70 4 times. After the fourth I unplugged the rail pressure gauge from the rail pressure sensor and it hasn't done it since. I haven't had time to really troubleshoot the issue so I can't say that was it but am just happy it isn't doing it anymore.
 
wow my truck hasnt died, and i had the issue before installing the rp sensor so that isn't my problem. best of luck finding the problem. when did your check engine light come on? did you install anything new other than the rp guage?
 
If memory is correct it came on just after starting up the truck. Knock on wood still working as it should, but will probably plug everything back in this weekend to see if it was maybe just a loose connector.
 
Again my $$$ is on the dry side ,if it was on the wet side RPMs would be effected,be it little they would still have some change.
 
Airsick yours sounds like what happened to me with the QUAD RP gauge harness. I filled with dielectric grease and zip tied the connectors together......no more problems.
 
if it were a loose connector tude HPCR nut you would have a hard start along with low rail pressure not rp "creep up". it could be a sticking FCA, hard to diag the FCA cause there is no real good test for them. a know good FCA would help check.
 
Well guys I finally got some new cross over tubes put in and now I have even higher rp at idle! Now at idle the rp likes to hover around 14k to 15k and spike around 17k. What gives!!? The next thing I am going to do now is send my cp3 off to get tested. Im still finding it hard to believe it is the cp3 being that I did not have this problem before the injectors.
 
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