is surging during acceleration a sign of fuel rail pressure fluxuating and not staying constant. and if so will a lift pump cure this.....???
surging???!!!
- Thread starter dracing70
- Start date
If yes this can be a sign of No lift pump.
Log your runs with EFI and watch desired fuel rail pressure and actual fuel rail pressure and you will have your answer. If the actual is dropping below 19k psi or so you need a lift pump. Odds are you will see low numbers in the 10-12k psi range
Log your runs with EFI and watch desired fuel rail pressure and actual fuel rail pressure and you will have your answer. If the actual is dropping below 19k psi or so you need a lift pump. Odds are you will see low numbers in the 10-12k psi range
Make sure you have a EGR blocker plate. No blocker = surging.
Ditto for Pressure Relief Valve Shim / Race valve.
Ditto for Pressure Relief Valve Shim / Race valve.
Pat whats your opinion on the shim kit/race valve debate? Some people say you will blow something up with a race valve on a truck thats driven much, others say they have a race valve and no ill effects.
Not Pat, but with enough shims you have a race valve and Blue has a bunch
with 50k plus with no problems
There was alot of debate about whether a solid PRV or shimmed was a safety hazard. After thousands of trucks running shims and race valves, I've yet to hear of one problem that I would clasify as highly dangerous.
Usually, a problem is when they shim the valve wrong, or don't screw it in tight, it can make the truck run like crap, and sometimes leak a small amount of fuel. Very rare though.
Usually, a problem is when they shim the valve wrong, or don't screw it in tight, it can make the truck run like crap, and sometimes leak a small amount of fuel. Very rare though.
yep, 3rd is only for older trucks that have a weak spring where the 2 springs don't do it. So i have been told
Thanks Jason. Its weird mine pops on a smaller tune than 500, but wont do it on the Race Tune. Gonna tackle it tomorrow.
So DRacing... sounds like a lift pump is next on your list?
So DRacing... sounds like a lift pump is next on your list?
Thanks Jason. Its weird mine pops on a smaller tune than 500, but wont do it on the Race Tune. Gonna tackle it tomorrow.
So DRacing... sounds like a lift pump is next on your list?
Maybe
, mine would only pop at the end of a run when psi would spike to like 29k when I let off. Rail psi wasn't dropping to bad compared to some lb7 and lly's. would be done to about 23500+/- desired was like 26107
ok finally i am able to log on again. anyway yes my valve is shimmed and my egr totally eliminated the surging happens whether accelerating hard or normally it will accelerate then all of a sudden surge up and up then hesitate and so on. is this the lift pump problem? you can see my mods is not havin the lift pump hurtin me?
You will need to datalog the truck to find out what the surging is.
If the actual rail pressure isn't following the commanded, then a lift pump can help.
If the actual rail pressure isn't following the commanded, then a lift pump can help.