Every time I do a wide open run up past 80 mph I set a po 93 code, check engine light and it cuts fuel instantly. It also did this to me last time I truck pulled. I was running Big VA, Predator 120, and my injects. I am running a Holley Blue lift pump. I put a Genysis on and the rail pressure is down to 13,900psi right before it trips the code. I need to figure out how to fix this. I cant make a 1/4 mile run or pull down the track with it right now.

Is that overboost?

nope, it is when the difference in commanded vs actual fuel rail pressure is more than 20mpa.

A P0093?


Going to have to try a bigger Lift Pump supply IMO.





Mac Edited by: Mackin

I know I need more fuel, but I dont think that is going to fix it. What do you reccomend for a lift pump, dont say a fass or prepator, they are way overpriced.

Has anyone found out for sure that a fuel pump is the cure-all or is the HPFP simply unable to deliver reguardless of supply?Edited by: hoot

I said try.


With the Programming your running I hardly think that is the programming minus any bursting issues is the problem.Now In combo with Injectors, you maybe sucking it dry and have a supply issue.





Give Kennedy a call he MAY have a pump(s) that will produce reasonable.





Mac

I'd check injector return flow first. Then on to fuel pressure sensor(just got mine replaced and fixed most of my issues). Or check vise versa.


Hows your mileage????? and power feel compared to months ago, or when you weren't getting the large fuel leak detected code???

FRPCV another if never changed is a valid look at as a possible issue as the sensor HBC is mentioning.


I have had my Rail sensor replaced,she was a big leaker.





Mac

FRPCV another if never changed is a valid look at as a possible issue as the sensor HBC is mentioning.


I have had my Rail sensor replaced,she was a big leaker.





Mac








Just had my whole block changed(failed the diagnositic test miserably) The block with the sensor and valve is cheaper than the sensor by itself, go figure. Truck runs better now http://www.dieselplace.com/forum/smileys/Big Smile.gif

Well, let's see what we have here. Someone correct me if I am off, but here's my take using some general numbers that I just pulled out of my arse:


Say the factory calls for say 90mm3 of fuel. Predator adds say 60% to get 120HP (maybe more) for 144mm and a 60% longer pulse. The big VA is likely up around 90% so it takes the 144mm pulse duration to 273.6mm or approx 3x the original for say 500RWHP on #2. By comparison, we can hit 450-470HP with a 100% extension from stock.


So stacked, we now have one heckuva long pulse, and fuel chasing the piston down the hole. There's a TON of fuel in the cylinder maikng a TON of heat energy, and a lot of fuel burning in the exhaust. We just happen to squeeze a couple more psi out of the already oversped turbo which manages to make another 30 or so HP over what one reasonable duration shot does.





Compound that 273.6mm pulse by 40% for injectors and we have 383.04mm3.





All that fuel for a couple dozen at best ponys...

WD, what's the lift pump pressure from the Blue when rail is 14,000?

Understandably John but IIRC most who get out past the Duty Cycle of the injector end up with a bucking truck.


I was thinking the Bigger Injectors are resulting in a bigger volume need . I don't doubt ponies will not be gained although.





Mac

Has anyone found out for sure that a fuel pump is the cure-all or is the HPFP simply unable to deliver reguardless of supply?


A lift pump is not the end all be all solution. The fuel system has several problems when playing at high Hp/Torque levels. The lack of a lift pump is the first thing one runs into, adding a pump that will keep the low pressure gear pump full at all speeds and loads is a big help. Once you cross that bridge you will need to replace the pickup in the tank as it causes a pretty good restriction in the tank and causes most pumps to limit outlet flow. Now when you get beond these, depending on how much power your making you will run into the stock fuel filter flow issues. Each and everytime you fix one thing all you do is find the next week link in the chain. The above three fixes will give you enough fuel to support about 550 RwHp from programming, stock injectors on #2. Add a little gas and water and were at 793 RwHp in Colorado. http://www.dieselplace.com/forum/smileys/Big Smile.gif

Thank you for the help guys. I dont have a fuel pressure gauge so I dont know what psi or vacuum the pump is doing when the light sets. I would like to redo the entire fuel system but I dont have the funds right now while Im in school. I will be done soon so hopefully I can get all that and maybe some air then.

There is a good possibility that your lift pump is becoming a restriction when flow increases.





I've gone to a pump setup that can flow through quite easily in the event of a failure. These pumps will also run more freely as the flow rate increases helping to pace the system.





My point is, that by my loose calculations, you are calling for a theoretical fuel rate of over 4x the OEM, and I still think that you can make as much or more power with less fuel. Heck I think IIRC my truck with injectors (305 RW) gained another 60-80 HP with just a little shot of N20 and there really wasn't any smoke to speak of without...

So you are saying I will make just as much power just running my Big VA program ony? I am going to replace my fuel pressure sensor junction block and hopefully it will stop setting the cel. How much flow is your pump putting out JK?

I don't think SuperDiesel was stacking , just adding lots of alternative fuels/air...





Once I get the next version samples in, I'll know more, but 6gpm is possible based on 1/2" pipe conduit.

I believe I would get a Westers and run that if Im going to run a single program because it will actually allow me rpms and 200+ hp.