Code p0088 p0251 after floor it cp3 and 125 nozzle install

[Mobius1]

I am getting a code p0088 on startup. I have gotten code p0251 once but I cleared it and the p0251 went away however the p0088 remains. I've searched the forums and its seems the most common problem is the fca. I have a rail psi gauge and while cranking it will jump up to almost 26k, and idle like crap. After a couple seconds, the rail psi stabilizes to about 5800- 6000 and idlse fine. Truck runs strong, no problems while running at all. Is it most likely an fca? I know john from floor it Custom makes his fca to match the customers truck.



Thanks in advance

 

[BLoging]

if the truck stumble's on and off different times wile idling or going down the road then it may be the fca. did you find out what the code was that may help to fid out if it is the fca. i know there is a few diesel shop's out there that may lend a used good one to try out to see if it is the fca before you buy a new one.

 

[Mobius1]

p0088 is fuel rail psi signal above max limit
p0251 is cp3 pump regulator control

P0251 has not come back since I cleared codes. P0088 comes on right away I watch my rail psi go right up to 25. 7kpsi, truck starts and idles like crap. Then rail psi comes back down to 5800-6000 and it idles and runs fine after that. I'm going to try my old fca that I have and see if that fixes it. I know floor it specializes their fca to the individual customer. Perhaps a bad one was cut?

 

[TCDiesel]

What is the lift Pressure? If its above 15psi that may be the problem. . those modded FCAs are touchy , I have had my share of failures.

My guess is the internal spring is mis-aligned.

 

[Mobius1]

What is the lift Pressure? If its above 15psi that may be the problem. . those modded FCAs are touchy , I have had my share of failures.

My guess is the internal spring is mis-aligned.

Its right at 15psi floor it says to run fp at 20-24psi. I haven't increased the lift pump psi yet.

 

[TCDiesel]

I would ask John before turning it Up... Their is some performance to be gained By higher lift, but it comes at a price,Surging and lopping at Idle.

 

[cerberusiam]

Perhaps a bad one was cut?

Thats the usual problem. The modded FCA's are a picky critter at times. The code is from the rail pressure going over the limit and that is from the FCA either sticking wide open or just not functioning correctly on start.



At least it didn't default the other way and you end up with a no start.

 

[Mobius1]

Just got off the phone with my dealer who was talking to john over at floor it. He said make sure the COV is tight and try to swap my fca from the old pump. If the truck starts and idles fine with non codes then its a bad fca and John will send me a new one!



I will keep everyone informed of what I find out



P. S. he also said 15psi should be fine as far as pressure to pump

 

[Mobius1]

A bad rail pressure sensor will toss a P0088, mine did.

I do have a spare one of those too. I can try that as well.

 

[Mobius1]

Just took the truck for a little spin. Found out rail psi is all over the place. IT jumps from 16 to 20 to 15 to 21, basically its all over. Truck surges. Pretty sure I have a bad fca

 

[Mobius1]

Tried my old fca, idle is more smoother, rail psi does not jump around while driving and surging is gone. I def had more power with the modded fca compared to the stock one.



Its hard to believe that little bugger can cause that much problem!

 

[TCDiesel]

Yep I now mod with New 2 Stage spring... Bosch must have change spring material and pressure. . For Years we used the factory spring... No problem... I'm willing to bet if you push the spring keeper in 1/16" the Modded will start and work good... It comes at a price. . less performance...

 

[Mobius1]

Yep I now mod with New 2 Stage spring... Bosch must have change spring material and pressure. . For Years we used the factory spring... No problem... I'm willing to bet if you push the spring keeper in 1/16" the Modded will start and work good... It comes at a price. . less performance...

Actually John is going to send me a new modded fca