Sam Ali

HI,

Does anybody knows what is the vacuum reading of VQ30 engine at idle ? I am trying to check for vacuum leaks. My gauge is reading 43 cm/hg (16.9 inch hg) at idle about 750 rpm, on stock VQ30DE with MEVI...

Thanks,

Stephen Max

iTrader: (59)

Sounds just a tad low. I think 18-20 in hg is pretty normal.

nick

iTrader: (10)

it is low, use throttle body cleaner or propane gas to look for vaccum leaks around IM. Start the engine , spay the TB cleaner/propane gas and look and hear for RPM's jumps.

Nick.

Sam Ali

Thanks, Will do that next.

The engine has been misfiring and vibrating eversince they were put back by my mechanics, change coil packs, remove and clean injector , tested and calibrated... Change sparkplug, check PCV, clean TB/IACV and misfire always on cylinder 3, no matters how I rotate the coils or injector. However, as rpm increase, the miss is decreasing as tested using power balance method...