jus83

G'day mates, I have a 97 Silverado in Australia. I have recently replaced the motor with a 330hp crate motor as the old engine was only 290HP.
Now the new motor is leaning out at crusing speed eg. 2000 RPM in 3rd and 4th overdrive.

No one over here knows how to reprogram the computer so I was wondering if a UNICHIP piggyback computer will fix this problem or I was possibly thinking of running a carburator and getting an autoelectrician to re wire the computer to run the auto only.
Any help will be very much appreciated.

Cheers
Jus83

shamrock246

did you check the fuel pressure?is it throwing codes for lean banks?they have an upgraded spider assy for the fuel injection that gets rid of the poppet assy's

Sean
97 4x4 burb

jus83

i have replaced the spider injectors and the fuel pressure reg and have no codes. what is the upgrade fuel injectors?do they put out more fuel? cheers jus83

shamrock246

the upgrade replaces the the injection unit with the poppets with conventional style injectors not sure if they flow any more (the injector is out by the port not in the main body) maybe there is a bigger injector that will fit,my boat in powered by the same engine but with the marine style manifold it looks simular but the injectors are on the outside and there is no EGR i have seen on the net people convert them to use with automotive engine adding an EGR,that manifold would probably take bigger injectors but i think that conversion can be expensive, the engine is a 330hp Crusader marine inboard

Sean
97 4x4 burb

shamrock246

hope the link works
GM Performance :: View topic - Vortec L31 MARINE MANIFOLD project! Q&A


Sean
97 4x4 burb