Crazzy idle. And sputter. Miss fire idk pissin me off.

[POSz32]

Hey there new to forum. Got a problem an figured yall could help. I have a 1990 300zx n/a bought the car a few weeks back. Had an issues when the car got hott. It would sputter/ miss like hell during mid throttle but if i floor it it would be fine. Changed fuel pump. New plugs fuel filter. O2 sensors. Now the car has gotten worse it does it right on start up has a fluctuating idle wants to die at idle still sputters at mid throttle. Kinda sound like a 2 step launch control. Its pissing me off just dumping money into it and i need some help i have a video but i dont know how to upload it. Any help would be greatly appreciated.

[POSz32]

The exaust smells like s*** also

[nissanfreak12]

Hey there new to forum. Got a problem an figured yall could help. I have a 1990 300zx n/a bought the car a few weeks back. Had an issues when the car got hott. It would sputter/ miss like hell during mid throttle but if i floor it it would be fine. Changed fuel pump. New plugs fuel filter. O2 sensors. Now the car has gotten worse it does it right on start up has a fluctuating idle wants to die at idle still sputters at mid throttle. Kinda sound like a 2 step launch control. Its pissing me off just dumping money into it and i need some help i have a video but i dont know how to upload it. Any help would be greatly appreciated.

Do a leak down test or compression test. If its getting or got hot and running like crap, might me the head gasket.

Vac leak?
Fuel pressure? Have you tested it?
What type of O2 sensors did you get? If you had to splice the wires together, make sure its done to the correct wire.
How are the injectors? Have you ohm tested them?
When was the last time the timing belt was changed?
Have you checked the ECU for codes?

[POSz32]

No ecu codes. O2 sensors were plug and play. I haven't checked the fuel pressure. Or compression. No vac leaks. And it don't look like timing bet was ever done this car wasn't well taken care of at all. Could it be the mass air flow? I unplugged it and it started to idle fine. But doesn't rev of course.

[POSz32]

The exhaust smokes black when messed up like un burnt fuel.

[POSz32]

Have no idea how to do a ohm test but i do have a multi meter.

[KiDoZ]

Look for my one post about cylinder 1 misfire. . The guys in there help me with my issue with pictures and answers. Mine was doing same thing. It's idles so perfect now. I can barely tell the car is on.

[POSz32]

All injector read about 12 to 13 ohms exept one is at 16.3 or something.

[nissanfreak12]

All injector read about 12 to 13 ohms exept one is at 16.3 or something.

Your 16.3 one is out of spec, that will cause the sputter/popping. If you have the old style, they all will fail soon. Personally, just plan to go to the new style. Money well spent if you plan on keeping the car.

[POSz32]

I cleaned the contacts its running fine for now. But have a feeling when it heats up its gonna do the same. If its the one that reads high do you think that that injector is my problem forsure?

[POSz32]

Yup just started messing up again.

[POSz32]

Cant be the injector. Just unplugged while running made car idle worse

[POSz32]

Did the same with all coils unplugged also

[KiDoZ]

As someone who just saw one injector go out. Minutes later another. Within a few hrs had several go out. Be ready. I just did my injectors. It's a task if you don't know what you are doing. But it's well worth it. These folks on here know there stuff. My car runs fantastic. Knock on wood. They are gonna go out. Best be ready to order new ones. Plenum pull on the way for you good luck with it.
Your car will survive.

[POSz32]

Lol it looks like a b**** to do but if it has to be done it has to be done.

[KiDoZ]

Check to make sure they installed correct spark plugs and not 2 dollar plugs. These cars are picky.
Ohm all injectors
Check for green corrosion on all contacts and clean off.
If 1 fires and 2 doesnt. Swap out coils. And see if problem follows it.
Check spark plug for spark and make sure they are tight.

If stuck ask the pros. Not me. I don't know diddly. Only what I was told worked for me.
Lol.

[POSz32]

Just found a decent fuel leak after passenger side fpr.

[nissanfreak12]

Just found a decent fuel leak after passenger side fpr.

If you have an injector at 16 ohms, it is bad, plain and simple. It may still be working, but its not working correctly, and your car will run like crap until it is replaced. Not cleaned or rebuilt, replaced. Our injectors are picky, especially the older style(square top) due to the ethanol blends in the gas. The higher the number gets, the more fuel it will dump in the engine, till one day it will either stop open or shut.

Replace all six, otherwise you will be doing the replacement a lot more than once. Its not hard if you have done the main deletes, but if you haven't, it kinda sucks. Let us know if you need any help with it.

[Ace2cool]

Also, if it's an issue of being hot, then you COULD check your PTU. Is it new black style or old silver style?

[POSz32]

Compressions all around at 120psi

[t.mcginley.jr]

Compressions all around at 120psi

Are you sure you did the compression test right (engine warm, full battery, etc.)? 120 psi is very low for a vg30de engine.

Anyway, wacky idle and sputtering can be a number of things, but it's probably your injectors. The one that ohm'd out high is definitely busted and the others might be messed up too even if they ohm within spec (which is 10-14 btw) because they are old-style injectors (prone to failure). It might also help if you cleaned the MAF with MAF/electrical contact cleaner and the IACV with throttle body cleaner.

You should just pull your plenum off, change out the injectors and all the fuel lines while your in there.

[POSz32]

I just bought the tester at harbor freight. Its probably broken. Imma take it back tomorrow. I have a feeling its the mass air flow i cleaned it about 2 hrs ago runs better messed up for like 20secons on test drive than stopped.

[t.mcginley.jr]

Have you checked for error codes yet? Usually a bad MAF will come up with a code 12. When mine threw a code 12 while driving it was ridiculous, it completely stalled at one point and even when it didn't the rpms would go up and down constantly while hitting the gas or even idling

http://www.nicoclub.com/archives/nissan ... ostic.html

[POSz32]

No code what so ever. I have that front panel off that covers the air box and mass air flow and its running pretty good right now. I can unplug the o2 sensors and mass airflow. And no codes show up at all

[POSz32]

Does anyone live near reading pa an want to fix my PoS ? Lol

[POSz32]

Does the mass airflow get hot during use ? Maybe cause i have that panel off its getting cool air on the mass and making it run fine ?

[t.mcginley.jr]

The MAF gets uses a hot wire to measure to air as it goes by, so it doesn't matter if its hot or cold air. It could be that its just dirty, have you change your air filters?

I live in NJ so I'm kinda far from Reading lol if it was Philly it would be more possible

[KiDoZ]

Damm. I was in reading today. Just saw this. I know a guy in ephreta who might be willing yo look at it. Try to stay calm though. This will piss you off but in the end YOU will fix your car and be proud of it.
I'd say. Replace injectors of one is bad. The others are two. I had 3 ohm out good but were bad. Yes 3. Order them from whoever these guys recommend and install them. By 2 ft of gas hoses and replace with new ones. Get new plugs if those are old. If the are hard to remove then they are old most likely.
Try to take it in steps ok.

[POSz32]

Well idk its going to my buddy's shop tomorrow morning im just gonna let him find the issue if he cant pin point it than i will change the injectors ill let yall know why he says tomorrow. How long did it take you to do your injectors? And how much did everything cost you?

[POSz32]

They are like 160$ a piece at autozone its ridiculous