Hello everyone, I have searched the forums for a few days before taking the plunge and asking for help.
1992 Non Turbo fresh JDM import. I have finally decided to import my dream car, the 300zx!
She drives off the transporter with a few misfires and perhaps a missing cylinder (not literally thankfully) and i get her parked up on my drive. Do an oil change, OEM filter, OEM fuel filter too, 6 irridium spark plugs "version 7" from z1Motorsports; slap them in. Put 6 litres of V-power to get it to the MOT garage. Next morning she starts on a dime, all 6 cylinders singing and happy no misfires. 60 seconds later the revs start to go up and down without settling, i pull off to the garage, very hesitant, loss of power, the engine wants to stall but the accelerator just barely keeps it going sputtering and stuttering luckily it was just 5min up the road.
During the diagnosis period the spark plugs performed worse and worse eventually it wouldnt start at all leaving a rich deposit on the plug that was also wet with fresh fuel on every cylinder.
We put the original stock quad tip exhaust
New coolant temp sensor, A fresh set of 6 coil packs, tried 3 Different PTU's with clean terminals.
Had an electritian bring his scan tools and everything checks out, no engine codes except for 55( all clear)
O2 sensors are working (disconecting them increased the fuel even more), theres fuel pressure,
Dropped the tank and cleaned it( it wasnt even that dirty), flushed the fuel lines
Cleaned the MAF and terminals, tried starting it without the MAF plugged in, tried cleaning all the connectors.
Tried to clean the TPS sensors, Tried to By-pass the knock sensor, Obviously checked all the Vacuums but yet to do a smoke test.
Im gonig to test the Fuel pressure regulator too because the car ran allot better with an external gass tank and weaker pump, hopefully its the FPR sending too much fuel to every injector.
the only other thing i can think of are the injectors, but what are the chances of all 6 getting stuck-open.
Also as soon as we put new plugs in the car starts like a dream for a while.
I would apreciate any troubleshooting at all, hope there is still some ZX veterans around here. Also im in West London.
Hello everyone, I have searched the forums for a few days before taking the plunge and asking for help.
1992 Non Turbo fresh JDM import. I have finally decided to import my dream car, the 300zx!
She drives off the transporter with a few misfires and perhaps a missing cylinder (not literally thankfully) and i get her parked up on my drive. Do an oil change, OEM filter, OEM fuel filter too, 6 irridium spark plugs "version 7" from z1Motorsports; slap them in. Put 6 litres of V-power to get it to the MOT garage. Next morning she starts on a dime, all 6 cylinders singing and happy no misfires. 60 seconds later the revs start to go up and down without settling, i pull off to the garage, very hesitant, loss of power, the engine wants to stall but the accelerator just barely keeps it going sputtering and stuttering luckily it was just 5min up the road.
During the diagnosis period the spark plugs performed worse and worse eventually it wouldnt start at all leaving a rich deposit on the plug that was also wet with fresh fuel on every cylinder.
We put the original stock quad tip exhaust
New coolant temp sensor, A fresh set of 6 coil packs, tried 3 Different PTU's with clean terminals.
Had an electritian bring his scan tools and everything checks out, no engine codes except for 55( all clear)
O2 sensors are working (disconecting them increased the fuel even more), theres fuel pressure,
Dropped the tank and cleaned it( it wasnt even that dirty), flushed the fuel lines
Cleaned the MAF and terminals, tried starting it without the MAF plugged in, tried cleaning all the connectors.
Tried to clean the TPS sensors, Tried to By-pass the knock sensor, Obviously checked all the Vacuums but yet to do a smoke test.
Im gonig to test the Fuel pressure regulator too because the car ran allot better with an external gass tank and weaker pump, hopefully its the FPR sending too much fuel to every injector.
the only other thing i can think of are the injectors, but what are the chances of all 6 getting stuck-open.
Also as soon as we put new plugs in the car starts like a dream for a while.
I would apreciate any troubleshooting at all, hope there is still some ZX veterans around here. Also im in West London.