Help!!! 92 300zx n/a smoke and fuel out of exhaust.

[Cerealkiiller]

Hey guys, new here and new to these cars in general. I have done my research and searched the forum and google and I'm still stumped. Here is the story.
I got the car 2 months ago with injector #3 not working. The car ran pretty good minus the miss and didn't smoke at all. I acquired a used fuel injector last week to install in the car. I replaced the injector orings with brand new ones from Nissan and installed the injector using the Dremel method, so I never pulled the plenum or anything. The only thing I touched was #3 injector, nothing else.
Now the replacement injector doesn't seem to be working either, but that's not my main concern. The car starts and runs like before but now it smokes terrible and also has raw fuel coming out of the passenger pipe. The smoke is mostly concentrated out the passenger exhaust, but there is some that comes out of the driver exhaust. I assume because of the h pipe underneath. Also this car is completely factory stock with 68k original miles. Somebody help me out if possible. Thanks. I can upload videos of it running too if that helps. It's not burning oil or coolant either.

[Cerealkiiller]

http://youtu.be/k4feVuH0ZN0

http://youtu.be/q7LKXSA-tcw

http://youtu.be/DmVMQM5Atic

[Cerealkiiller]

Nobody? Would really like to get her back on the road ASAP. Any help is appreciated.

[twinturbozxtacy]

smoke looks white to me from the vids and in the later ones it doesnt smoke until you gas it. could be coolant... fuel smoke is black coolant is white. pull the plug and take a pic. check your coolant levels.

[Cerealkiiller]

It's not coolant. The wreaks of unburnt fuel when running. It's def fuel. You can see the fuel drip out of the exhaust pipe on the passenger side. I literally did nothing but pull the old injector and replace it with a different one. No other change, then it started smoking. If I first start it and let it run it won't smoke heavy, just very light once the exhaust gets hot. Then obviously when I give it some accelerator, it smokes and blows everything out of the pipes. The coolant level is topped off where it should and has been. The oil level is as well. I haven't lost any coolant or oil and no contamination in either as well. It's fuel, plus the fact that I only swapped out an injector makes me even more positive it's just fuel. However I don't know why it's dumping all that raw fuel. I'm afraid to drive it and hurt anything so I haven't driven it to try to clear the exhausts. But it has ran prolly a total of 15 mins or so since it started smoking. Not all at one time though. I dunno. I'm stumped and frustrated with it at this point. I do however appreciate the feedback and help. I'm just hoping someone has had the same issue as mine at one time.

[Phan]

dude, these car are really sensitive. learn from me and never buy used/remanufactured injectors. put out the money and do it right the first time.

start out by replacing the injector with a new one and see what happens then start of from there. http://www.conceptzperformance.com/Cart ... 169.144.92

remember to ohm check the injectors. they should be around 10-14 ohms

I suggest you stop driving the car until you can solve this problem.

[240RB1]

I think you pinched/tore the rubber o rings on the injector and now gas is bypassing the fuel injector and leaking out the back....as for the smoke,maybe the fuel is trying to reignite in the cats and smoke is being let off becaus of it?

Ohm test the injector....like Phan said,it should be between 10-14ohms.i litterally just replaced all 6 in my z lol

[Phan]

I also want to add. NEVER take out the injector while the car is hot. My face was so swollen from fuel shooting up into my face while I try to pry that sucker out. There is a lot of pressure in the fuel system so let it completely cool then proceed. Just for precaution take out the battery too especially on these hot weathers. GOOD LUCK!

[Cerealkiiller]

Thanks for the replies. I first put in the replacement injector reusing the old orings off the injector I took out, started it and it smoked. Somewhere online someone said that you can't reuse the injector orings because they were compression orings. I drove to the Nissan dealer and bought a new upper and lower injector oring, lubricated the orings with a little bit of Vaseline and installed it. Still smoke. I've uninstalled and reinstalled the injector a couple handfuls of times now. I have checked inside the rail where the injector slides in also for anything keeping it from sealing, I've even cleaned it lightly with a q tip. I am currently not driving the car at all, unless it needs moved In the driveway for some reason. I know used wasn't the way to go for the injector, but new wasn't in the budget at the time, and I figured it couldn't miss worse than it did with the old injector. Now I just wish my only problem was the missing and that I don't have to deal with he smoking. I just find it hard to believe that the orings aren't sealing being new and all but I guess it could happen. I thought the injector might be sticking open so I put the old injector back in and it still smokes. On a side note the injector I got came out of a car that was parted out due to a blown head gasket, makes me wonder if the head gasket wasn't blown at all on his and maybe it was this injector...ha.

[Cerealkiiller]

Whenever I go to pull out the injector I also pull the fuel pump relay before hand to let the car die, then crank it a couple times and then release the pressure from the fuel cap. Yes there is a ton of pressure in that rail if you don't release it...lol.

[t.mcginley.jr]

Ok first things first, good call on cranking it with the pump relay pulled. Never work on the fuel system without releasing the pressure

Now, your fuel injectors are going to be crappy either way because they are old style. Pre-1993 injectors are prone to failure because the ethanol in today's gas basically corrodes them from the inside. There is a conversion kit that will run you about $120, but you will have to pull the plenum (or dremel the remaining injectors) and solder in the new style electrical connectors.

As for buying remanufactured injectors, there's nothing wrong with buying new style remans but not old style. I have a new style set on my 90 NA with the adapter kit and I have zero problems.

Yes, its very likely that you pinched an o-ring on the install. I did it twice before they finally seated correctly. The easiest way to tell is with it running, do you smell fuel near the plenum? If so, its leaking. That will for sure make your exhaust smell like gas. The other possibility like I said is just bad injectors.

IMO, you should save up for a few months and get the adapter kit (~$120 from Z1 or whoever), a reman'd set of new style injectors (~140 on ebay from seller tlfperformance), and new fuel rail insulators (~$10 or so). It's really not a huge undertaking, but when you go to install the injectors, use PLENTY of lube. I know you said you used "a little" vaseline, but that's what I did the first time and 2 of the o-rings pinched. You gotta make sure they are lubed up good.

And yes, the injectors should all ohm out between 10-14 ohms. Great indicator of bad injectors if any are outside this range

[Cerealkiiller]

Thanks for the advise man. I may go out here in a bit and pull that injector again, lube it up really good and reinstall it. I do not however smell gas coning from anywhere except the exhaust. Nothing in the wngine bay if i remember correctly. My question is this. If I get it reinstalled and everything is great, how long should I still see smoke, smell fuel? I'm sure there is a ton in the exhaust pipes, but I wonder how long it should take for it all to burn off, especially without driving it. I'm talking just idling in the driveway, maybe stabbing the throttle a couple times. I just don't wanna risk driving it if it isn't right. Plus the plates have been expired and I didn't renew em because of the way she sits currently.

[Cerealkiiller]

Also you think I have to buy new orings yet again or should these ones be ok. The look fine. Then again so did the original ones.

[Cerealkiiller]

I went out and pulled the injector again. Lubed it up really really good and reinstalled it. Made sure it was seated good and put new gas in the car because it ran out. Started it up, still smokes like a b****, and now I'm getting smoke under the hood after its been running for a few minutes. You can still see fuel just spitting out the passenger exhaust pipe. I honestly don't know what to do. I know it's gonna need a new injector, but at this point I don't care about the miss, just wanna get it to quit smoking and spitting fuel. I'm afraid of damaging the engine or hydro locking it. All the sudden I want to just set it on fire...damn.

[Cerealkiiller]

http://youtu.be/cK1MnrwkYXE

[Cerealkiiller]

http://youtu.be/zM-dPQIZUto

[twinturbozxtacy]

unplug that injector and see if it still smokes after a few minutes. if so your new/replaced injector is not the problem. it is possible your old injector wore out that cyl and now its burning oil... power-balance test with both the coils and injectors. let us know.

[Cerealkiiller]

Even if I unplug the injector it still smokes and spits fuel out of the cylinder it seems. I can't see it wearing out that cylinder after only installing replacement injector and starting right up. It literally didn't smoke or do anything funny at all, just misfire, swapped out the injector and instant smoke and fuel out of that sides exhaust. I'm not sure what you mean by power balance test with coils and injectors? Thanks for the reply also. I've already gotten a lot more advise here than other forums. It is much appreciated.

[twinturbozxtacy]

power balance look it up, it help with any car! so basically either that injector is stuck open all the time dumping fuel into the intake constantly or one of your other injectors are bad. since you said its not oil or coolant, that the only other possibility.

and yes a dead cyl/mis fire can kill a cylinder pretty quickly depending on what was bad. if it were a coil and the injector was working the fuel would build up and wash oil from the cyl walls basically killing that cylinder in a few hundred miles or so... a dead injector not so quick but eventually would have the same outcome.

[Cerealkiiller]

Ill look into it right away. Thank you again. Nice to get some help somewhere. Nobody local messes with these cars. I actually haven't seen another one on the road but mine...well when it was on the road anyhow. Lol.

[twinturbozxtacy]

where you located?

[Cerealkiiller]

I'm in Akron, Ohio. I looked up the balance test too. When I got the car I did that by just pulling the injector plugs, but not the coil ones. #3 cylinder made no change. That was my faulty injector and the one I replaced. I also used a screwdriver to listen for them to click, that's still the only one which doesn't have a loud click to it. Ill have to check out the coils tho. My money is still on injector 3 not working, I just don't know why all the sudden after the change she smokes and everything so bad. When I got the car I noticed a slight miss to it. Now I wish I would have just passed on it. I just figured an all original Z with 68k was gonna be worth my time...haha.

[twinturbozxtacy]

let us know, and orig with low miles... probably not as everything dry rots/corrodes or glazes over.

[Cerealkiiller]

Yeah I've always loved the way these cars look. But now I'm regretting picking this one up. Makes me wanna bash in the firewall and put in a sbc and be done. Oh well. Can't always come out on top I guess.

[twinturbozxtacy]

its only worth the work you put into it... unless it a toyota ha ha

[Phan]

dude, look... take things one at a time. frustration won't fix your cars problem.

Just start out by disconnecting your coil pack connector one by one to see which is the dead cylinder. Then after you find out which cylinder is dead do a ohm test to check the resistance. Once you find the culprit its just a matter of installing a new injector in and your problems should be solve.

Here's a good way of installing the injector without worries about pinching.



1/2" Pipe from Home Depot



use the rubber hammer to lightly hammer down the injector and remember to lube it good with a 10w-30 viscosity. (Top and Bottom O-ring and also inside the injector fuel rail.)

[twinturbozxtacy]

i dont use a hammer, i turn back and fourth to wiggle in... hammers are bad news, not all the time but at least from what ive exp with fragile engine parts. but he is right one step at a time! just lube them up real good first thats all, also inside the rail too.

[Phan]

you'd be surprise at how easy it comes in with generous lubrication and light tapping.

[twinturbozxtacy]

lmao ill leave that alone...

[Cerealkiiller]

Hahahaha. Ill try it again tomorrow but kinda seemed like it snapped in place. Didn't seem too difficult. Maybe it's not going in the rail all the way. Ill try It tomorrow. Thanks again.