1992 z32 non-turbo 300zx leaking injector

[vvaffle]

I searched a bit for this but can't seem to find what I'm looking for. A friend of mine has a 91 N/A 300zx and one of his cylinders doesn't work. It's the middle cylinder on the right if you were looking from inside the car if that makes any difference.

I swapped the spark plug with a working cylinder and the problem didn't move. The spark plug from the non working cylinder was quite covered by fuel. I assumed this was an injector issue but is there also a chance that the spark plug is not getting a spark? If it is an injector issue, would it be a bad injector or leaking o-rings?

Also, how complicated is it to get to the injectors if they are the problem? I have replaced injectors in my 240 but they are much easier to reach. hopefully someone can help me out.

[180fan]

shouldn't be too bad getting to the injectors. Might want to have a check over on the ignitor if the plug isn't firing. Then to see if it's the injector that's acting up on you, pull the plug on it, it should close up at that point and if the plug is still wet, you've got a leaky injector.

[vvaffle]

a few questions: -the ignitor is the part where all the spark plug wires come from right?-how would I check if its getting a spark from there?-if I find that it's a leaky injector, do I have to remove the top part of the intake manifold to get to them?

thanks for the answers so far.

[180fan]

So here's some related stuff for your current issues. I've nailed both the coil pack test and the ignitor test from the service manual. All you need now is a multimeter.

Test that stuff out before having to cough up/going through hell for an injector that you may not need to pull.

[vvaffle]

thanks. I'll try this in a few days so hopefully it's something easy to fix. I hope you don't mind me asking, but do you have the whole manual in digital form or know any place that I can get one?

[180fan]

not sure where you can get the entire fsm. I do have it all scanned in from it's different sections for different years of the z32. Not exactly sure where I could host the file without getting kicked in the groin with bandwidth issues.

[vvaffle]

this might be the most delayed reply ever but iv been really busy since the winter and didn't get much of a chance to work on it plus the problem is sporadic so sometimes it works fine.

I tested the all of the ignitors and they all reading 1 Ohm, including that one for the sometimes non-working cylinder.

Recently, including today, all the cylinders seem to be working because there is no constant vibration at lower RPMs and pulling the ignitor cable on each of the cylinder does make the engine stumble. However, it does occasionally smell like fuel.

I pulled 3 of the spark plugs including the one for the cylinder that didn't work and they all seem pretty much the same. They don't look good, but I don't see any differences. I took pictures but I am having trouble uploading them to the gallery. (anyone know why? they seem to upload fine but don't show up.)

Another thing I noticed, while the engine is running there is a hissing noise behind the right bank of cylinder if you are looking at it from the front of the car. When you turn the car off there is a very loud hissing noise. I am not sure if this is related or not but I recorded it, here is the mp3 file.

http://home.comcast.net/~vvaffle/300zx_hiss.mp3

Also, I have no idea where that second part is from the image you scanned.

Any ideas?

[vvaffle]

bump. help please. at least with that hissing sound.

[elwesso]

I want to rule out the possibility of it being fuel related.

Run the car and pinch the fuel line, and then turn it off. After a minute or so, pinch it again and see if it feels softer...

More accurately you could hook up a gauge and see if its losing pressure.

Ive seen nissan injectors leak from the lower O rings causing them to run stupid rich.

[vvaffle]

I tried the pinching thing, didn't feel any different with the car on or 1 minute after it was turned off.

The hissing sound I recorded sounds like a vacuum leak but I'm not sure.

[vvaffle]

any new ideas? we ran chevron fuel injector cleaner through the car and it still lacks power still.