I've just booked my NA Zed in for Plenum Bypass Surgery at Dontex in Vermont. I've been quoted about $1000 all up. The coolant temperature in the Zed was a bit high when I got her home yesterday. I could hear steam escaping somewhere at the back of the engine but couldn't see where it was coming from. This morning I checked and there was a fair bit of coolant missing from the radiator. I figure it's best to just get everything back there torn out and bypassed to prevent any future problems.
Depends ... Print the below lists out and ask them to confirm which of the jobs and parts listed they will be performing. I wouldn't expect a commercial style workshop would do everything but it is a good guide to see what value for money you are getting. As a general rule, all required NA parts as per my list (and you should replace them all when you have the plenum off) should cost in the region of $300-350'ish depending on source/exchange rate etc and injector servicing from around $150 p/6. the rest is labour. You should also ask for a follow up check on fuel line clamps which always need tightening after a few weeks. Jobs recommended during an NA plenum pull: Plenum 'pull and push' Soldering all ten injector / CTS / AAC / FIDC and Air Regulator wiring plugs Inspect/Replace and refit exhaust and intake valve covers using gasket sealant/gaskets etc Fit new crankcase breather hoses, PCV's and gaskets Under Plenum water hoses bypassed Inspect/Consolidate AIV, PRVR and EGR system piping/solenoids/wiring etc Inspect/Replace all vacuum hoses IACV (idle control unit - AAC & FIDC) unit dismantled and reconditioned Throttle bodies/linkages checked/adjusted R&R Injector rail and injectors including new O'rings Fuel hoses replaced TPS and idle adjusted ECU diagnostic upon start-up Drive test and re-tune as required Follow up inspection to check for fuel/water hose leaks etc Parts recommended to replace: Nissan OEM 300ZX PCV Complete Hose Set Non Turbo - part # NA: NIS300-11810CSET Nissan OEM 300ZX Air Regulator/AAC Valve Hose Kit - part # NA:NIS300-14099NA Nissan OEM 300ZX Plenum Gasket - part # NIS300-14033 Nissan OEM 300ZX Balance Tube O-ring Set - part NIS300-14033-P05/06 Nissan OEM 300ZX AAC(IACV) Gasket - NIS300-23785-40F Nissan OEM 300ZX Injector O-ring Set 90-94TT/90-92NA(93CV) - NIS300-16618-10VKT Nissan OEM 300ZX Heater Core Hoses - NIS300-92400 Nissan OEM 300ZX Intake Valve Cover Gaskets - NIS300-13270 3 Metres of 8mm heater hose (ensure the internal diameter is 8mm - some "5/16" inch labelled hose is actually 7.9mm which is a pig to fit) 1 Metre of 8mm high pressure EFI hose (ensure the internal diameter is 8mm - some "5/16" inch labelled hose is actually 7.9mm which is a pig to fit) 10 Wiring connectors for: * Injectors x 6, * CTS (Coolant Temp Sensor x 1) * AAC (Auxilary air control x 1) * FIDC (Fast Idle Direct Control x 1) * Air Regulator x 1 Note: there are many other jobs that can be performed with plenum off, the above should be considered a ballpark guide.
