280z dies randomly while driving..

[cclxxxz]

can a going bad MAF cause this problem? 

[cclxxxz]

On 2/23/2019 at 5:11 PM, Zed Head said:

Begin here -

 

downloaded and reading it..

[cclxxxz]

On 2/23/2019 at 5:11 PM, Zed Head said:

Begin here -

 

downloaded and reading it..

[cclxxxz]

 

Good morning!

So yesterday.. I replaced the water temp sensor.. cleaned the bullet connectors.. i also test for continuity on all of the pins in the ecu.. i am not quite convince with my test ill probably redo it and document it and take a video. 

so when testing for continuity any type of reading means its good correct? 

i am getting some reading on the following..

TVS (full throttle) 

AFM

ATS

WTS

Air Regulator

Thermotime Switch

Ground Circuits all good..

 

except for TVS at Idle switch .. am i suppose to get a continuity when in this position?

i also tested..

Revolution trigger signal

Power line circuit

Cylinder #1-6

and all 12v+

 

I did a fuel pressure test.. with a brand new fuel pump and fuel filter.. i also dropped the tank and inspected if i have any rust above and the tank looks good just dusty.. i can hear the pump working and making a sound.. the ground and positive wires are in good conditionat the pump.. (although i want to track the wiring along inside of the car to check its not grounding out) 

 

when i performed the fuel pressure test.. i followed the step by step of the FSM by releasing pressure first by jumping the CSV.. then disconnecting the starter and ignition coil..

i uploaded to video here.. 

it looks like its reading 38psi.. and when i connected everything and with the car idling .. its at 32psi..

car idling..

 

and today 2/25.. on my way to work.. just about 10mins of driving .. the car died while in 5th gear in the FWY.. pulled over and kept on trying to start the car.. eventually the car started and drove fine got to the gym.. and on my way to work from gym.. about 5mins of driving the car died again.. after trying to start the car a couple of time.. started fine again and i got to work..

 

during lunch break i checked my spark plugs.. 

 

Edited February 25, 2019 by cclxxxz

[cclxxxz]

I tested my Air Flow Meter today..cleaned it , inspexted the flap and also my friends to compare.. same result on both AFM his also has No Resistance when testing 6 & 27.

 

So i am getting the right resistance for the following terminals except for #6 & #27 which is the Air Temp Sensor..

 

Terminal 8 & 6 , Results - 199.8

Terminal 9 & 8 , Results - 114.2

Terminal 6 & 27 , Results - No Resistance

 

 

 

 

[240260280]

Immediately Check for Spark:

The next time your car dies and you pull over, immediately pull HV wire from centre of the distributor and place it back next to one of the driver side nuts at the top of the strut. Have it ~ 1mm from a nut.

Crank the car and see if you see a spark jump from the wire to the nut.

Practice at home a few times checking for spark.  You may need to take some tape to hold the wire in a convenient spot.

[cclxxxz]

33 minutes ago, 240260280 said:

Immediately Check for Spark:

The next time your car dies and you pull over, immediately pull HV wire from centre of the distributor and place it back next to one of the driver side nuts at the top of the strut. Have it ~ 1mm from a nut.

Crank the car and see if you see a spark jump from the wire to the nut.

Practice at home a few times checking for spark.  You may need to take some tape to hold the wire in a convenient spot.

will do thanks!

[cclxxxz]

 

a quick update from last night..

 

AFM tested and great numbers except im not getting any resistance from my air temp sensor.. 

 

am i missing something to this step? i tested my friends also and no reading.. made sure i cleaned the contacts and i even opened my AFM and tested from the inside..

 

i also tested the water temp sensor in car while it was cold (didnt get a chance to check when it was hot) insulation was good and the reading i was getting was about 1.1 ohms .. 

 

i also checked my EGR Valve and i thought it was fair clean and somewhat new the valve isnt stuck .. 

 

i also found a small crack in the BOOT between the AFM and TB. I just wrapped it with electrical tape as much as I can for now until i can get a new one..

 

i have noticed a couple things before calling it a night.. when i wiggle the bullet connectors (i cleaned them all but after cleaning and filing its a little loose specifically the water temp sensor wires.) the cars idle would change sometimes it sounds like its idling better sometimes its idling rough.. so i just taped the connectors in placed .. to keep them tight and pushed agaisnt each other..

 

i also noticed that the two prong water temp and thermotime swich connectors are both after market and it was soldered after the bullte connectors nearby the thermostat housing..

after securing the bullet connectors, i tried slightly wiggling the whole harness trying to fogure out if its the connectors by the sensor and the idle also changes.. 

ill try and see if i can replaced those two prong connectors .. 

 

new water temp sensor installed btw..

[Dave WM]

there are two issues going on here poor idle etc... prob a rich/lean fuel condition. Continue to search out the sensor that is the problem and resolve it. could also be a EGR allowing exhaust gas in at idle. second issue is the intermittent die, this is going to be harder to find, as mentioned isolate to fuel or spark. I mentioned in your video leaving a visual spark test tool installed for now so you can quickly check next time it dies. You will need to have someone help you by cranking while you get out and look for the flash in the test tool, or just bring a spare plug along and be ready to use it. Practice using it so you know exactly what it should look like when the car is working. loss of fuel could be and I do mean COULD be an ignition switch issue. Check it before just replacing and if you do replace check the new one before installing.

for me the problem was difficult starting, not cutting out while driving, but it would not be impossible for a defect in the continuity of the "run" circuit I suppose. Seems like if that were the case you notice issue with other electrical so this is a long shot. DONT just replace unless something test bad, that's just throwing away money.

 

Edited February 26, 2019 by Dave WM

[Captain Obvious]

9 hours ago, cclxxxz said:

I tested my Air Flow Meter today..cleaned it , inspexted the flap and also my friends to compare.. same result on both AFM his also has No Resistance when testing 6 & 27.

You have your Ohmmeter on the 200 Ohms range. That means the meter "pegs out" at 200 Ohms and any resistance reading higher than that reads as "1    ." There is probably nothing wrong with the air temp sensors you are looking at. You probably just have your meter on the wrong scale to get the proper reading.

At room temperature, the air temp sensor should have a resistance of about 2200 Ohms. So if you try to read that on the 200 Ohm scale, it won't read. And even the next scale up (the 2K scale) is too low as well (since the resistance is greater than 2K Ohms). At room temperature, you'll probably need to go all the way up to the 20K Ohm scale to get a reading off the ATS.

The resistance drops as the temperature increases, but the colder it is, the higher the resistance. Check it on a higher range on your meter and see what you get.

Edited February 26, 2019 by Captain Obvious

[cclxxxz]

17 minutes ago, Captain Obvious said:

You have your Ohmmeter on the 200 Ohms range. That means the meter "pegs out" at 200 Ohms and any resistance reading higher than that reads as "1    ." There is probably nothing wrong with the air temp sensors you are looking at. You probably just have your meter on the wrong scale to get the proper reading.

At room temperature, the air temp sensor should have a resistance of about 2200 Ohms. So if you try to read that on the 200 Ohm scale, it won't read. And even the next scale up (the 2K scale) is too low as well (since the resistance is greater than 2K Ohms). At room temperature, you'll probably need to go all the way up to the 20K Ohm scale to get a reading off the ATS.

The resistance drops as the temperature increases, but the colder it is, the higher the resistance. Check it on a higher range on your meter and see what you get.

Cap!

will retest and this is my fault .. thank you for catching this .. i knew documenting it would help me pin point the issue..

 

is the reading on TVS at “idle switch check” also pass 200+? ohms? I am not getting any reading on terminal #2 and #18 on the throttle valve switch..

 

will try to play around with it today thank you again!

[cclxxxz]

39 minutes ago, Dave WM said:

there are two issues going on here poor idle etc... prob a rich/lean fuel condition. Continue to search out the sensor that is the problem and resolve it. could also be a EGR allowing exhaust gas in at idle. second issue is the intermittent die, this is going to be harder to find, as mentioned isolate to fuel or spark. I mentioned in your video leaving a visual spark test tool installed for now so you can quickly check next time it dies. You will need to have someone help you by cranking while you get out and look for the flash in the test tool, or just bring a spare plug along and be ready to use it. Practice using it so you know exactly what it should look like when the car is working. loss of fuel could be and I do mean COULD be an ignition switch issue. Check it before just replacing and if you do replace check the new one before installing.

for me the problem was difficult starting, not cutting out while driving, but it would not be impossible for a defect in the continuity of the "run" circuit I suppose. Seems like if that were the case you notice issue with other electrical so this is a long shot. DONT just replace unless something test bad, that's just throwing away money.

 

Dave,

thanks! i will check the switch today and give an update later.. ive been told so many times to test and not just replace and i guess out of frustration i just replaced things.. as of yesterday i started testing things so it will be my new standard of trouble shooting moving forward.. 

 

issue #1 - im guessing it could be in this order.. water temp sensor (including the bullet connectors and the two prong connectors) , air temp sensor and tvs..

 

issue #2 - i checked the egr valve last night and the valve isnt stuck and its not clogged. i didnt check the pipe underneath though.. the vacuum hose on top is good and connected..

 

when the car died on me this morning i pulled the ignition coil wire and it tickled me stupid mistake but panic mode i guess.. lesson learned.. but i guess i have spark while the car is in “struggling mode”..

 

i disconnected the water temp sensor and the idle improved.. i did this so i can get to safety..

 

will trouble shoot more and any tips , advice .. much appreciated! 

 

btw i dont know if its good to mention but this issue never happens to me during mid day or at night..  it doesnt get too cold here in the morning .. lowest probably 40 degrees.. normally around 50 degrees outside..

 

heres a video of the car stalling while driving this morning.. 2/26... at 6AM.. 

 

Edited February 26, 2019 by cclxxxz