Keep getting P0088 code with SCT tuner???

[cgb6810]

I've got a 08 F450 CC, 4x4, DRW with cat/dpf delete, 5" magnaflow, banks CAI and an SCT tuner. Driving the truck around town is fine but as soon as I start pulling my 7k lb work trailer at 70-75mph down the highway I will blow P0088 code after 40 minutes or so. This first happened using the extreme tune so I put in the performance tune and all was fine. Now I continue to pull this code. And when it goes, the engine goes into some kind of default/detune mode. I lose my cruise control and the truck will not go over 63 MPH. The turbo pressure will not go over 1/2 the gauge when in this mode. If I turn it off and restart it's ok again for about 10 minutes and it goes back into the limp mode. Put it into tow mode and the same thing...

P0088 is fuel system rail pressure-too high.

Any ideas? Would a Spartan tuner fix this issue or does it need to go to the shop?

BTW I got nearly zero increase in fuel mileage with this setup on any tune. Quite a disappointment.

[sledfreak]

fuel rail pressure to high if you click on any of the problems forums then go to the top of the page click on the problem forums that puts them all together the scroll down it lists them all in the sticky

[DavidPhillips]

Those directions have me lost.

[cgb6810]

Yeah, I wasn't following either. I think he meant the sticky that list the codes? but not sure.

I read on another forum that this is happening to others with spartan tuners as well. Im strongly considering putting it back to stock. I have to use this truck daily for work and i must depend on it.

I made the changes for fuel mileage increase but have seen very little difference. I think it's because Im turning so many RPM at 75mpg (2,750). I would be better off trying to change the gearing.

[SCUFFY828]

p0088 usually means pump is goin bad

[younggun55]

Where are you located? There is 3 of us on here located in san antonio with spartan tunes and when it the weather heats up we all limp our trucks with the p0088

[DavidPhillips]

Ah yes, the trouble code sticky. Thanks.

Do you think the fuel is overheating causing the sensor to trigger a code?

Maybe you should check the lift pump pressure. I realize that sounds like the opposite of the problem but it does not seem likely that the pressure would be too high. It seems more likely that your starving for fuel and the lack of fuel flow makes it hotter.

If it is low pressure to the high pressure pump the damage could be severe.

Just an idea.

[forcefed6.4ford]

I believe its the lift pump not being able to keep up with the HPFP. The way it was explained to me is that the HPFP pulls the pressure down between it and the lift pump. As the pressure balances out the HPFP make a mini pressure pulse as the lift pump starts to keep up(but not really). Kind of like a air hammer. That is what is setting the codes. A better lift pump like a FASS or AirDog should cure the problem.

[DavidPhillips]

Yea, I'm not sure about these HPFP's but on most of the old injection pumps they would not last very long if there is not a good fuel supply. I think the main problem was that the fuel was used to cool everything and if there was not enough fuel flow to have an excess amount of fuel coming through the system it would over heat. It would also run low on fuel and that would be lost lubrication for the pump. Injectors also depend on cooling by the fuel.

Has anyone checked fuel pressure yet? Maybe several of them are getting cooked by lack of fuel from the lift pump.

I have a pressure gauge in line with my input to the injection pump on my old Chevy. With a new lift pump it normally reads around 2 to 4 lbs but can drop to 0 lbs momentarily under a load.

[SCUFFY828]

fuel delivery isnt the issue , the p0088 gets set when the fuel rail pressure sensor sees a difference in demanded fuel pressure and actual rail pressure , ive seen this a couple times now , rail pumps were tried and had no effect on the issue , fuel temp doesnt come into play here either , further diag will show a hpfp will be the culprit