Hello everyone,

I hope you dont mind a Kappa guy popping in on your forum; but I have a question in regard to the limits you have attained on the stock fuel system (Low Pressure Side). I am aware of the high pressure side and the code now being available (Trifecta is my current tuner, Westers/ HPtuners; BSR; I have tried them all!) Anyway I have a GT35R turbo swap running with a Catless DP and a Gizzmo EBC, 3 inch exhaust, etc. I have run into a limit, or so I think I have. In discussions with Vince at Trifecta and the latest logs I have given him I was getting a P0087 'Low Fuel rail pressure' DTC and in conversation he stated I may be asking more of the low pressure pump now that the high pressure side is 'open' and the system couldn't keep up. So here in lies the dilemma, I did a parts ID search and found your stock in-tank pumps are the same from '08-'10 model year while mine is an '07 Sky/ Solstice only.. Has anyone seen or experienced the limits of their in-tank fuel pump?

As a side note, I was at 28PSI and 143mph, the 2 times this has occured... I am pushing the limits of my car, I realize that and if I crack piston #1 or bend a rod, just means 'new part' or an LSx upgrade

 

Theres not many of us running large turbos yet...and the ones that are have run into the "fuel pressure" problem and have struggled... I would contact ZZP as they are the current highest hp LNF and see if they can give a little assistance.

 

zzp has only mentioned the high pressure side...but I would think running 400-500whp they may of run into that issue...I concur they would be a good contact just to see for sure.

 

Thanks for the input, I have heard of ZZP, I guess I will post this on their vendor side and see if they have any input as well. Any other comments/ questions are welcome.

 

It takes 5 seconds for that DTC to be set so it is starving for fuel 5 seconds before you get to 143 mph. Try an inline booster pump to help fuel flow.

 

you better be careful, you might burn up your injection pump if you are starving it.

 

The high pressure fuel pump is the one he is starving. It is cam driven not electric like the in tank one. The only thing he is likely to burn up is his motor from running lean at 28 psi and 50 lbs/min of airmass.

 

i dont know everything about gas direct injection, but on a Diesel aplication, the fuel is what lubricates the injection pump, if you starve it, you can cause damage to the internals of the pump, unless gas DI is different. This problem is very common on 2nd Gen ram diesels when the lift pumps go bad.

 

It does help lubricate the pump. I misundertood what you ment LOL. I thought that you thought that the OP was talking about a regular electric in tank or inline low pressure pump. Sorry

 

Thanks for the input everyone, I was thinking pigyback too, but was trying to just mess with the in-tank if possible. Oh well. I have contacted ZZP to see if they have any input and another vendor on the Sky/ Solstice side to see if I can integrate a pump into something they already have available for the low pressure side.

 

Look into dropping in a Walbro 255. It will be good for much more flow. I am not 100% sure what it would take to modify the stock tank for the 255, but I know it can be done with some ingenuity.

 

Do you happen to know the flow of the stock unit Matt? I know its 60PSI going to the high pressure pump, but dont know about the flow rate.

 

No, I don't know the flow of the stock guy, but the 255 is good enough to support like 600hp, then you can just double it up to support more.

I just got to thinking, the code is saying rail pressure is too low, which means the issue is not the in tank pump, it is likely that you are commanding too much pressure from the hpfp, and the pressure sensor is seeing that its not enough.

 

Here's the link...

http://s141.photobucket.com/albums/r68/306Eleanor/Sky/