300zx Update (More MAF Issues) 300zx Z31 

i may be late to the party but i had this problem about 8 years ago which was a result of water leaking through windscreen into ecu destroying the fuel pump circuit, the fuel pump cuts off about 10 seconds after starting the car unless you put your foot on the gas raising the revs, i have a second ecu that works but it operates on a different o2 sensor so i just added a fuel pump relay that turns on when the ignition is on, car no longer cuts out. if it was an air flow sensor issue it wont happen with sensor unplugged but you also wont be able to go over 3thou revs with no air flow sensor

If you’re going into a STEM field, consider taking a large I/O a/d count microcontroller and wire it into all the sensors (to log all the data). I did this during my EE undergrad while diagnosing my z31 88 Turbo. I had a closed loop issue which ended up being an O2 sensor issue (the O2 sensor behaved perfectly under test, but under WOT it would misbehave - logging all the data made it stand out as the culprit). Maybe try running a temporary harness back to the ECU to rule out the MAF wiring?

I've had a very similar issue before on the 85 I used to have. In my case I think the issue was a combination of a bad MAF and a bad ground to the crank positioning sensor. So what I would try, if the connector you ordered doesn't fix the issue, is to replace the MAF wiring harness since it seems your issue is in the MAF circuit. The wiring in these cars really seems to be their Achilles heel. Good luck and thanks for the videos!

You can send it to rockauto and they will rebuild it.. I had the same issue... after rebuilding the MAF same issues.. it turned out both grounds from the MAF connector need to be grounded to the body. I spliced wired leading from c & d and grounded them to the body - runs fine now. I literally tested all leads to ECU..

I don't mean to be a pain in your ass I just wanted to let you know I really respect your videos I've had these cars for 20 years I know I told you that a million times I've got a picture of me in front of my first one in July of 99 it was my slick top 84 Datsun LOL but I just wanted to tell you that I put your videos playing back-to-back and listen just to learn anything I don't already know and get ideas and advice I listen to you even when I can't watch your videos I just listen through my Bluetooth while I'm walking around at work I've recently started a little RU-vid video and I'm going to start making them better but mine's just more less to show off my car and I really don't work like you do on video but I do show off a lot of things and show my new parts but you've motivated me to do the RU-vid channel you know I'm not trying to compete against you or anything like that but I just love seeing videos of the Seas when I come across them I had to add mine to it too anyways save as many of them cars as you can busy car anyway I want the z32 I have a 74 240Z it's going to be a strictly v8 car though I wish I still had my 87 but it got stolen when I was in a wheelchair but anyways I'll still have my 86 that I've tried to get you to look at there's multiple videos on my RU-vid of it I'm done about everything I want to do to mine other than paid it turbo it and coilover and I'll be finished pretty much

Compare what values you get at the MAF and at the ECU plug to rule out the wiring.

Do these cars have IAC valve? If you have to feather the accelerator air may not be bypassing the butterfly valve… could try cleaning

I'm having the same exact issue with my Z, I went ahead and changed out injectors, FPR, spark plugs and wires and will still have to feather it to hold the idle

I love your channel, can you help me with a question I just purchased a 1984 300ZX turbo. And I noticed they have the same cold air intake filter like you do. But he left the old equipment in the trunk. Why is everyone removing the old filter and putting in this cone looking one like you have?

Nissan Service Manual 300ZX PDF Format, for free.

Where can you locate the check engine light connecter on the ZX?

First

Where could I find a replacement MAF for my Z31? Could I use a Z32 MAF?. My z31 only starts/runs under 2000rpm with the MAF unplugged, won’t run at all with it installed. Any advice would help thanks !

I am curious to know what the fox to this problem was. Im having the exact same issue. I sometimes start the car and runs fine, after few mins it stalls, sometimes it will run very rough since starting it. i hit the gas and it revs up for a second and comes right down amd stalls or almost stalls. Please help!!

Hello again guy, was just watching your MAF videos again thinking maybe that has something to do with my current issue in my 85. I have tried all the forums with absolutely no luck so the hunt to find a solution for my mid range power loss continues and it's driving me mad. It's a long story but have you ever had a power loss around 2500 rpm that drops back to 1500 rpm and pulsates back to 2500? I looked through your videos and didn't see anything similar so I thought I would ask you directly. Thanks for your time. LB

Mine wont even start without maf

Did you find what the MAF issue was? Also I have an 86NA which actually runs ok - feels like a bit of stumbling sometimes on idle. I unplugged the MAF and it was definitely worse, wouldn't run at all, just start and die.

My 85 NA starts but only idles and with and gas pedal it dies immediately. Been trying to figure it out. Would you look to the MAF

Have you fixed it yet? I’m having the same problem when I unplug the maf it runs only to about 2000 rpm

That looks exactly like my slicktop

My z has the same issue.. I’m trying to figure it out.. the idle smooths out when I disconnect the vacuum on the fuel regulator but has new regulator and new pump.. 🤔

How do I tell what maf I need

So my 85 Z31 is having a similar issue but i checked the maf and it looked fine. What my car does is it runs and cranks up just fine but when it gets to a certain RPM it bogs down and doesn't wanna go any higher in rpms. Any idea of what it could be?

Did you ever fix this bro? I have a similar issue with a rough idle.

I’ve unplugged my MAF and my car still won’t start

I am having this exact issue on my Z31. Watching this video definitely helps with troubleshooting and diagnostics. Just super close to being able to drive my car again. Once i get the MAF figure out, I'll be able to take it back out on the road. Other than that, what was the ultimate fix you had to do to get your car running again?

curious about your air filter, what size cone is that?