shane87urban
SDD Junior Member
I just installed the blue spring and a fuel pressure gauge. Pressure is at 60 until I get on it then it drops to 50. But at wide open it'll drop to 35. Any ideas?
fuel pressure low at wot
- Thread starter shane87urban
- Start date
how agressive is the tuning?
stock fuel pump might not be able to keep up with fuel delivery..
shane87urban
SDD Junior Member
It's a custom tune on my sct by Matt but it was only my 2nd highest tune. I put it on street mode with set's preloaded tune. It only drops to 40 at wot. My question is would a new fuel system like fass or airdog fix that issue?
OK.. here's the thing you have to remember..
Diesels are throttled by the amount of fuel they get. They always get 100% air..
Think of your injectors as eight fuel leaks.
At idle or low demand (cruise), not much fuel is demanded, so they don't leak much.
At WFO/WOT, their running max duty cycle, so they're going to be open longer, and leak more.
The more they leak, the lower the pressure is going to be in the system.. think of a soaker hose.. small holes.. more pressure left.. cut the end of it off, large flow, low pressure.
I guess my best advice to you would be to call Matt and ask him with fuel pressures he thinks you should expect.
But I'm thinking if you are going to run aggressive tuning and have your right foot on the floor all the time, then yes, you may want to upgrade the fuel supply system.
Personally, I think you're OK. If you had said the pressure falls to less than 12 or 10psi, you're in trouble.
In the meantime.. maybe change the fuel filter and see what happens (if anything at all).. I mean hey, you're certianly not going to hurt anything trying the simple stuff first.
Hope it made sense, and hope it helps.
Diesels are throttled by the amount of fuel they get. They always get 100% air..
Think of your injectors as eight fuel leaks.
At idle or low demand (cruise), not much fuel is demanded, so they don't leak much.
At WFO/WOT, their running max duty cycle, so they're going to be open longer, and leak more.
The more they leak, the lower the pressure is going to be in the system.. think of a soaker hose.. small holes.. more pressure left.. cut the end of it off, large flow, low pressure.
I guess my best advice to you would be to call Matt and ask him with fuel pressures he thinks you should expect.
But I'm thinking if you are going to run aggressive tuning and have your right foot on the floor all the time, then yes, you may want to upgrade the fuel supply system.
Personally, I think you're OK. If you had said the pressure falls to less than 12 or 10psi, you're in trouble.
In the meantime.. maybe change the fuel filter and see what happens (if anything at all).. I mean hey, you're certianly not going to hurt anything trying the simple stuff first.
Hope it made sense, and hope it helps.
Last edited:
shane87urban
SDD Junior Member
Yeah I'm fixing to do the filters tomorrow I try to keep up on the fuel filters because I'm always running off road fuel. But I keep seeing that I could damage my injectors if my pressure drops to low just don't want that happening.
WD40
Full Access Member
I would sure hate to get caught running off road fuel, that can cost you a bunch of big bucks, around here the DOT pulls you over and sticks your tank looking for red fuel.
Doug
Doug
Damage, no.
In years past, off-road had a different cetane rating, algaecide/anti microbial, couple of other things.
Now, it's just the dye and tax rate.
K1, JP8, #2 diesel.. All pretty much the same stuff anymore. Ultra low sulfur.
But like Doug said.. dON'T get caught with it in the tank of anything with a license plate. Mega-fine.
In years past, off-road had a different cetane rating, algaecide/anti microbial, couple of other things.
Now, it's just the dye and tax rate.
K1, JP8, #2 diesel.. All pretty much the same stuff anymore. Ultra low sulfur.
But like Doug said.. dON'T get caught with it in the tank of anything with a license plate. Mega-fine.