93 n/a 2+0 Injector problems?

[datsik707]

Car has been running perfectly. All of a sudden last night, I started her up and it sounded horrible, like a subaru with the wub wub wub wubwub, maybe missing? So when i get down the road and decide to just head home, boom, everythings fine. After letting it sit for 3 or so hours and start it again, same problem, then 5-10 minutes later, everythings fine. Today I went to start it and it ran perfectly. Drove for about 20 minutes, parked for about an hour. Then the problem came back and stayed. I ran it quite low on gas to put in new gas with fuel system cleaner. No results in the 5 mile drive home. I daily drive it so I don't see how it could be bad gas. Strangely, I'm not really feeling a loss of power, also, when i put it in neutral and give it a little rev, it sounds smooth as butter. Thoughts please? I'm pretty confused.

[ThisIsSparTTa]

What tests have you done? Pulled ECU codes? Power balance? Ohmed injectors? Listened for injectors clicking? If you have a 93, you likely have early style injectors, unless you've upgraded or replaced them, which means they are probably dead, but you can travel that road once you've done more troubleshooting.

[Ace2cool]

When this initially happened to me, it was a broken connector on one of my coil packs slightly backed off. Pushed it on, all good again.

If you do the power balance test while it's missing and nothing changes, you've isolated the cylinder and figured out it's the injector. If, when you plug it back in
the idle changes back to normal, it's a loose coil pack connector.

[datsik707]

@Sparta: No codes, no clicking. Injectors as far as i know are factory.
@Ace: Will check tomorrow!
Keep throwing ideas out there guys! Will keep posted. Any useful threads you can link to checking items would be helpful too. I'm still learning.

[datsik707]

Hearing more like it might be the injectors because of it failing then working again, then ultimetly failing. So along with any other helpfull ideas, please throw any knowledge you can about the change, what i should get, and if i should replace anything else while I'm in there.

[Ziggy1621]

Also, is your PTU old or new style? Where is it located? It could be getting too hot?

[ThisIsSparTTa]

Your injectors should be clicking. You should also just go ahead and ohm them. A power balance test is really easy to pinpoint the problematic cylinder. Just pop off the coil pack connector on each cylinder. If the engine doesn't seem to change the way its running, that's probably the cylinder with the problem. If it struggles when you pull it, then that cylinder is most likely working properly. Another quick and dirty way to tell which side may have the problem is to stick your hand behind the exhaust, it should be a pretty constant flow, if one side isn't constant, the problem is likely on that side. The idea about the PTU is a good idea too. The subharness is known to corrode and cause problems. I cut my subharness and directly soldered the wires together.

[datsik707]

I will check the cylinder/coil pack idea.
@ziggy: No idea, it's a 93, so whatever came from the factory with that year.

[Ziggy1621]

I will check the cylinder/coil pack idea.
@ziggy: No idea, it's a 93, so whatever came from the factory with that year.

New style started in 94. So yours probably looks like the silver one n the left in this thread in-the-middle-of-a-tt-swap-t542867.html

[datsik707]

Ah alright. So am i just looking for corroded harness with the ptu or..?

[Ace2cool]

No, if your PTU is silver, it's the outdated one, and should be replaced. Nissan will replace it for free. If it's black, it's the new style and is good.

[datsik707]

Ptu is black, So it's not the outdated model.
Going to mess with the connectors now. Any threaded how-to's or pics would be lovely. Will update as I learn more

[datsik707]

http://imageshack.us/photo/my-images/248/badcar2.jpg/
http://imageshack.us/photo/my-images/221/badcar1.jpg/

So I took this one out while car was warmed up. Nothing changed in the cars idle. I think it's this one. The backside of it is falling off. Thoughts? The other ones are much much harder to get to. But as the engine did not change as this one was plugged in and out while running, I'm assuming it's this. The one by the oil cap, not sure what # it is.

[t.mcginley.jr]

If the connectors are the problems, get these:

http://www.z1motorsports.com/product_in ... ts_id=5001

The connectors are easy to de-pin, all you need is something pointy like a little pick and you can get the wires out of the old connector and into the new ones.

If the connectors really aren't the problem and pulling the connector did nothing to change the idle, the injector is dead.

[datsik707]

Pulling the connector did nothing to change the idle. There's no chance it's just a plug or coilpack?

[ThisIsSparTTa]

http://imageshack.us/photo/my-images/248/badcar2.jpg/
http://imageshack.us/photo/my-images/221/badcar1.jpg/

So I took this one out while car was warmed up. Nothing changed in the cars idle. I think it's this one. The backside of it is falling off. Thoughts? The other ones are much much harder to get to. But as the engine did not change as this one was plugged in and out while running, I'm assuming it's this. The one by the oil cap, not sure what # it is.

That is cylinder number 1. The other coil packs should not be hard to get to, or else you're doing something wrong. Check them as well. Also, I've read its fairly rare for a CP to go bad. Number 6 is a bit tricky, but can get pulled with a little finagling. Btw, standing at the front of the car looking towards the rear, on the left side, front to rear, the cylinders are 1,3,5 and right side front to rear is 2, 4, 6.

If you do determine its specific to cylinder 1: Take a voltmeter reading across the coil pack terminals. I forget which way it goes, but between one of the outers and the middle, you should be reading ~12V. If you're not getting a voltage reading, check your wiring. Next swap coil pack with coil pack rom another known working cylinder. If problem follows coil pack, then you have a coil pack issue. If problem doesn't move, swap the spark plug with a working cylinder, and follow the same thing. If problem always stays on cylinder 1, and your CP is measuring at 12V, then its time to pull your injector connector off and ohm test the injector. It should be 12-14ohms for stock.

[datsik707]

@Sparta: Very helpful, but will i need to pull the intake manifold to swap coilpacks? Like i said, new and learning. Any how-to threads are greatly appriciated!

[ThisIsSparTTa]

No way! There's just 2 screws that secure them to the plenum. With a little pulling they come right out. The spark plug is right under there and accessible with an extension and (I think) 16mm deep socket.

[datsik707]

That's what I like to hear good sir. +5 E-cookies for you.
last question i believe then will update sunday/monday when i actually am off work.
1. If I'm switching out coilpacks and plugs if that doesn't work, wouldn't at a few points in time only be running on 4 cylinders? Would i still be able to hear the difference if it is indeed one of those problems and #1 starts working again and I'm back up to 5?

[datsik707]

I lied.
2. Would a 1993 n/a 2+0 have old or new style injectors?

[ThisIsSparTTa]

90-93 have old style, 94-96 have new style. You should not be swapping coil packs and plugs with the engine running. If you're asking what happens if you drop to 4 or less cylinders, its not the end of the world, its going to sound like s***. Obviously don't drive it like that, or run it for long. It should return to normal once you've gotten everything back into place. Even if you balanced out to running 2 on each side, its still going to sound off, vibrate, etc.

[datsik707]

I only ask because of
http://z32.wikispaces.com/Fuel+Injector#Phases 1 and 2
Classifies 90-92 old 93-96 new.

And obviously not with the engine running, but say with my luck it's the injector and the packs. Just making sure haha.

[ThisIsSparTTa]

Wasn't aware NAs were different. Even so, they are 20 years old. Anyways, run the tests and see what comes up

[t.mcginley.jr]

Actually I think it was like a mid-1992 change, so the 1990-92.5 (not sure the month) had old style square injectors and the 1992.5+ ones had the newer oval style injectors.

[datsik707]

Haha well you can see why I was a little confused. But yes, I plan on doing things Sunday/Monday on my days off work. But now it's calling for snow. FML. Will keep posted on anything I figure out!

[pcproa]

On my last car Z with pintle injectors about 6 years ago it did exactly the same thing.
I changed one injector that worked intermittently. Then after a week of driving another one did the exact same thing.

Sometimes it would run fine on startup for 20 minutes then just start missing. Sometimes it would work again after a cooldown. Sometimes it would miss right from startup. Sometimes it would stop missing when I tapped on the problem one with a screwdriver.

[datsik707]

Did you ever find a permanent solution? haha

[ThisIsSparTTa]

On my last car Z with pintle injectors about 6 years ago it did exactly the same thing.
I changed one injector that worked intermittently. Then after a week of driving another one did the exact same thing.

Sometimes it would run fine on startup for 20 minutes then just start missing. Sometimes it would work again after a cooldown. Sometimes it would miss right from startup. Sometimes it would stop missing when I tapped on the problem one with a screwdriver.

I'll second that behavior. I bought the car with 1 bad injector, had it replaced at Z-shop via Dremel method. Then a couple months later 2 or 3 went down in short order. At first they were intermittent, I even got it to work for about 3-4 days straight with no problems, then right back. IMO, if you do figure out that you have the old pintle style and you have 1 bad, I'd just do them all. I wasted a lot of money and car down time having the shop do just the 1.

[pcproa]

Did you ever find a permanent solution? haha

The second time I replaced a single injector, it ran fine for a few months but I pulled the engine out for a bigger build which had newer style injectors, so I don't know how much longer it would've held.
I sold all those pintle injectors shortly after.