About time i make a proper post about the whole car now that i have time to seriously start working on it. I have 2 posts about individual issues and kept the info i gave relevant to those, but it seems like they have started to branch off into a general diagnosis and i might as well make a proper thread. I will edit and update this info as i do more diagnostics.
Symptoms:
crank but no start - video:
https://www.youtube.com/watch?v=zytTGZH ... e=youtu.be Previous owner says he took it to a shop and they got it to start using starting fluid
Knock sensor code - diagnosed, bad knock sensor or pigtail to knock sensor, put a resistor in the plug temporarily to continue diagnosing vehicle without worrying about ECU failsafe
nearly no fuel pressure - lent my FP gauge to a friend but i could pinch the line with my fingers while someone else primed the pump and it was spurting and barely putting out anything
temp gauge sits at certain level even when vehicle is off - picture:
https://imgur.com/a/ZhDc5XP not a priority unless it ends up being relevant to the no start
What has been done:
read FSM EF & EC-77 hard to start or impossible to start under normal conditions
checked all the fuses in the car one by one in all 3 fuse/relay locations - all good
replaced dead battery
replaced VERY worn down spark plugs with new NGK's
replaced a vacuum hose or two that were obviously cracked or not holding
removed knock sensor connector and checked for corrosion - no corrosion
put a spare 1M ohm resistor in the knock sensor connector, cleared codes, then cranked, code 55 but no difference to starting - will replace knock sensor once i can diagnose the no start and get it out of driveway, resistor will at least get rid of the failsafe mode so i can diagnose the car
replaced fuel pump with v6 altima pump that has the same flow rate as stock z32 fuel pump, have some fuel pressure but have not tested how much with a gauge yet, waiting for it back
Reconnected a large hose connected to the intake piping before the passenger side throttle body(picture:
https://imgur.com/a/roVsj69) , haven't delved into the vacuum system yet to know where it goes, but an open in the intake piping and a disconnected hose is only going to cause problems
Tried starting with pedal all the way to floor as manual says to do to check air regulator and A.A.C. Valve, no difference even in sound
relevant data:
air filter is some awful aftermarket thing that sits in a horrible place picture:
https://imgur.com/a/X8HqV43 so until i can get the stock airbox or a different adapter onto the front of the maf nothing i can do, but seems clean enough shouldn't cause a no start
Crank angle sensor functions(rpm gauge goes up when cranking)
pulled out CAS and spun it with ign on and all 6 injectors click
here is a video of the ScanTech OBD data while cranking with sound
https://www.youtube.com/watch?v=zytTGZH ... e=youtu.be
seems like both exhaust bank o2 sensors are sitting at 0.32v but they're too cold for that to be taken as valid data
MAF data seems to be jumping for low to 0.5v(possibly due to wind and me taking off the air filter for that video to check for different numbers and it being windy), goes to around 1v when cranking, no idea if this is normal because the manual only lists 0.8-1.5v at idle as a spec.
TPS is at 0.3v when spec says tps should read 0.4-0.5 volts
fuel pump is getting 12v+ and no resistance to ground
no oil dipstick in engine or car, no clue where it went but looking for a parts car to replace it and check oil levels
things i have not done but will do:
have not done compression test yet - lent a compression tester to a friend recently but will be coming back with compression results on all 6 sensors shortly
have not done fuel pressure test yet - FP gauge is lent out to the same friend, but there is at least fuel pressure now, will come back with FP test results
have not checked all the coil packs, put a tester on plug 1 just to make sure ignition system was working at all, and it is sparking
have not diagnosed or tested any part of the EGR system
drain and replace oil
look up good MAF specs and check MAF
look at all vacuum connections and make sure they are solid as well as ensure all intake piping is connected under the front bumper
adjust TPS, currently sits at 0.3v, FSM says 0.4-0.5v is spec for closed throttle