Hesitation issues after Whipple install

[rkomo]

Installed a new W140AX with a 3.5 pulley back in May and am getting episodes of hesitation in mostly the lower and upper RPM ranges. It usually takes place after starting off gradually or once you stomp on the gas in any gear. The car feels very strong otherwise with no other symptoms being present.

My tuner hooked the car up to the laptop last week & there's plenty of fuel and everything looks OK with the tune after running it on the street for an extended period. Didnt have time to strap it back to the dyno though. They feel it may be a bad cam or timing sensor that is causing the problem? Other than this, they have no idea what it could be.

Has anyone experienced something similar and did you find a fix?

Would greatly appreciate any input or ideas before I go back to the shop next Thursday.

Thanks in advance...:thumbsup:

 

[djtyau]

Yeah, I had that problem. The first tuner I used didn't know what it was so I switched to another tuner and he knew how to deal with it in the tune. I had to datalog some parameters to get it perfect, but I don't have that issue anymore.

 

[rkomo]

ttt

 

[TERMIN8TR]

probobly in the tune

 

[rkomo]

ttt

 

[04cobra13]

got the pprv deleted??

 

[rkomo]

got the pprv deleted??

No thanks, that was actually mentioned to me by another individual. I was going to bring this to the attention of my shop. That worked for you?

 

[04cobra13]

worked for me no hesitation what so ever..

 

[04sleeper]

The hessitation between shifts is common with returnless fuel systems. The best way to remedy it is to delete the PPRV, set the FRPS max from 90 to around 60 in the tune (Delta P + boost psi + a few psi for headroom), and most important is to dial in the fuel pump voltage table.

This is about the most you can do other than adjusting a few PID's in the tune.

The best way to get rid of it completely and have perfect steady fuel pressure is to switch over to a return fuel system.

 

[rkomo]

Thanks guys. I'm leaning towards the PPRV like everyone has been advising. Anyone else have some thoughts? Thanks...:thumbsup:

 

[Snakebite2k3]

pprv delete here