In the case of a leaky fuel injector dumping more fuel into the cylinder than it can burn, would that end up causing loss of power, rough idle, etc?

I'll have to get out and give it more of a smell, maybe it's coming from the exhaust. Anyway, if it's a leaking Cold Start Valve, would it tend to only smell when it's cold? Or would that not matter?

 

Si Senor... I mean Yes Sir (Sorry, I live in SoCal... ). It can cause all of those symptoms. If it's a small leak though, you may not notice it as much. Pull the spark plugs and see if any of them are wet or smell like fuel. If one or more do, then you either have a fouled plug, a bad plug wire or a leaky injector.

Rod.

 

Ooops, I forgot, Since yours seems to smell of gas under the hood, you probably have one that's leaking up top... or the Cold start valve... in that case, look around all the injectors and the CSV while someone is cranking on it or while it's running (especially on a cold start) and you should see at least a damp spot. Usually when the CSV leaks it will shoot up and hit you in the eyeball (been there, done that) but it may just spray a little.

Rod.

 

With a leaky injector/CSV, is there a chance of that causing a fire like the Z31's had? Or is it set up better on the S130?

 

It's more than just a chance, it's an inevitability!!! It's not a matter of if it will cause a fire, it's a matter of when it will cause a fire.

Rod.

 

fuel + heat... hum!!!

 

Had the leaky CSV deal. Smelled gas. I popped the hood to see what it was. Couldn't find any signs of leakage near the injectors. Had my girl start the car to see if that would help me find the problem. Took a shot right in the chest from the CSV as I was leaning over the engine to watch the injectors. As far as leaky injectors go, when I bought the car I had to replace the injector hoses cause they were cracked and leaking. After about two years the hose clamps managed to loosen themselves and caused the injector hoses to leak (that or someone got underthere and loosened almost all the clamps )

And if you want to talk fire hazard: try driving around without securing the battery down and the positive terminal exposed. A friend of mine had his car catch on fire from that and I've got a hole burned through the frame of my hood right above that post. I've got it held down with a bungee cord now and a cover on the battery.

 

Alright today has been kind of cold and I had to run up to the bank. So I gave the 280ZX a quick ride up there, on startup and a bit while pulling out of the driveway you seemed to smell gas, but it seemed to go away after a few moments. I'm thinking the leaking cold start valve is probably the culprit. On the way down the street I floored the pedal for a moment, my brother said he saw a white puff of smoke come out of the exhaust. He's not sure if it was alot, but he said it was really only for a moment(this isn't I hope anything bad is it?) Could it be just built up condensation in the tailpipe from not being run in a few days? The car doesn't overheat or anything or even seem to get hot(as in really over normal operating temperature). So I think it's probably ok. So I'm guessing the fuel thing is just the Cold Start Valve, oh and one other thing. I don't know if my oil pressure gauge is functioning correctly. When I start the car up, the Oil gauge goes about midway between half and 90, maybe a little less than that. While I was at the ATM I noticed that the oil gauge was now lower, below the halfway mark. As I was driving the needle seemed to move with my acceleration. If I accelerated the needle went up, if I wasn't it seemed like the pressure would slowly go down. Maybe a bad Oil Sending Unit? Anyway, I look forward to hearing what you guys have to say.

 

Sounds like your oil pressure guage is working just fine. If the pressure didn't change with rpm's... you would have big problems.

Rod.

 

Alright, as for the smoke? Would that be smoking to worry about or not neccesarily? I know I wasn't watching the rear view mirror at the time, but later I kept looking and I couldn't notice any other smoke. My brother said he was sure it was only a little, and it didn't start until about halfway down the street when I floored it.

 

It's really hard to say... White smoke is usually bad, could have been blue smoke from raw fuel burning... A little smoke after a cold start I wouldn't worry too much about.

Rod.

 

And the fuel could be from a leaky injector/csv, right?

 

have u pulled your spark plugs to see what the tips look like???

 

An over rich mixture can cause the smoke that Rod mentioned. This smoke can be mistaken for white as at times it almost appears that way. When you floored the car probably just dumped a lot of fuel and it wasn't able to burn it all. Plus if the car hadn't completely warmed up first then it was running rich by default anyways so flooring it just added more fuel. It's no big deal if that's the case. If it were a coolant leak than more than likely it wouldn't be a momentary problem.

 

I'm assuming it was white. My little brother who is 8 said he saw it as I got down the street. He said it appeared about halfway down the street when I floored it. Anyway I'd think you'd be seeing smoke all the way down the street, had it been more of a real problem.

 

Ok so today's been warmer, and I started up the Z. Well I just had it in the garage(with the garage door open obviously) and started it up. Seemed like no problem I didn't really smell gas this time. A little bit of a scent from the tailpipe, but not like yesterday. I had my mother stand behind the car while I had it in neutral. I revved it up, no smoke came out, so that's good. She couldn't really smell gas either. I'm assuming that it's related to the CSV. I want to get the spark plugs out, but I can't find the damn socket to take them out. My dad has nothing organized in the garage.

 

MY problem was fixed today with a new, warranteed set of spark plugs. No more loss of power at 4k RPM either. WOOHOO!! Back to running like a raped ape!!

 

Carl, you said you changed your Spark Plugs and you no longer smell gas? Cus when I've been looking. I've been looking around the injectors, even feeling around them, couldn't see or feel any leaks. Where is the cold start valve exactly?

 

Well, my smell was coming from the exhaust, and not from the engine. I believe, though, that the red circled area in the pic is the cold start valve...

 

yes it is the cold start valve

 

Alright, I've been playing around with it, I guess the fuel smell is just coming from the exhaust, it just seems to emanate around the car since it's in the garage. Anyway, it seems to only have the fuel smell just for a bit until it gets going. On startup I got a bit of black smoke. It was only for a few seconds and it was very little. I'm guessing it was just some buildup that sat there for not being run for about a week. I took it for a nice long drive last night. Everything went real smooth. Got home and pulled it in the garage. I didn't smell any fuel or anything. Apparently I'm just running a bit rich at startup?

 

On a cold start, it's supposed to run rich. So far what you describe sounds fairly normal. I wouldn't worry too much unless you find out that theres is a fuel smell under the hood or if it doesn't go away after warm up.

Rod.

 

Last night though it was cold, and at my work I parked. The car sat there for about 7 hours. I started it up, and got a bunch of smoke, just condensation I guess. That's what my friend said, it did go away and didn't come back. Ever since the 300ZX, I've just been paranoid about any kind of smoke that comes out of the tailpipe.

 

Don't think I've seen a Z31 in over a decade that didn't smoke under acceleration...
Or have a cracked/broken manifold.
or a leaking rack and pinion unit
or a bad oil leak
or an ugly exterior (ok, that was a cheap shot I know)

Rod.

 

Well mine had an ungly interior, cracked/broken manifold, and smoked all over. Didn't have an oil leak or leaking rack and pinion