Ok... well since 5liter isn't updating the thread I'll do it for him. hehe
The problem was with the one way check valve supplied by Vortec for SD cars. It wasn't large enough and was allowing the MAP sensor to see almost 2lbs of boost. We'd tried a host of things to pinpint the problem (actually he did) but when he hooked his boost guage up inline with MAP sensor the problem presented itself. He went down to Autozone and purchased an additional check valve and installed it inline with the Vortec piece. The problem went away. He questioned why the valve was large enough before the intake swap and not after. My only guess is that the volume of air in the new intake was putting more air out that Vac line than the Vortec check valve was able to vent before making it's way to the MAP sensor. All seems good now and he's pulling boost throughout the RPM range.
sorry i didnt update this thread... but today i threw a 8-9 pound pulley on and the problem came back at 7 psi!! i cant imagine having 3 damn check valves inline between thew intake and map sensor to not allow the map sensor to see boost can you?!!!
for a fact i know that the aUtozone one is alot crappier then the vortech... i ordered another vortech one overnight and should see it tomorrow.... IF 2 vortech check valves wont fix the problem, im gonna have to run all 3!!!! ahh
sorry i didnt update this thread... but today i threw a 8-9 pound pulley on and the problem came back at 7 psi!! i cant imagine having 3 damn check valves inline between thew intake and map sensor to not allow the map sensor to see boost can you?!!!
for a fact i know that the aUtozone one is alot crappier then the vortech... i ordered another vortech one overnight and should see it tomorrow.... IF 2 vortech check valves wont fix the problem, im gonna have to run all 3!!!! ahh
Or run that restrictor we were talking about between the MAP sensor and the check valve. That'll slow it down enough to let the check valve do it's job. The check valve you have may be just gunked up inside and not allow the airflow through that needs to get through.
Are you sucking oil into the check valve, 1 really should be enough. You need to figure out why it is failing, I'd make sure the FMU is correct as well before upping the boost.
i can tell ya right now the car is running rich for a fact.... but about oil in my check valve, it kinda looks dry to me.. but if that was the case, why would it be?