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Discussion Starter #1
Ok, my 77Z 2+2....200k miles, stock. Was running just fine until I was at a 4-way stop just down the street from my house, then something happened but I don't know what. Car won't start unless you hold your foot on the gas, and will die at idle if you take your foot off the gas. Almost acts like it has some bad gas or something, but its missing and black smoke is coming out the back pretty visibly. The oil level is fine, and I checked all connections but can't find anything wrong. I wasn't driving the car hard, I was driving normal...probably didn't go over 4krpm all day long. **** I hope its nothing major....any ideas??

Thanks,
Kevin

77 280Z 2+2
97 Probe GT
02 Altima 3.5 SE
 

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Discussion Starter #3
You think a clogged filter could cause the black smoking? The fuel filter has been on for only 8 months and about 1200 miles.

Kevin

77 280 2+2
97 Probe GT
02 Altima 3.5 SE
 

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No -- just trying to give you an easy check for the poor idle and lack of power. Sounds more like a fuel mix problem with the fuel injectors. It might be electrical in nature. I don't know. But others here can give you better troubleshooting options than I can. Somebody will surely give you some good advice later on this PM.....

Good Luck
 

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Same thing happened to me last year when I went through a carwash that
sprayed under the car and the AFM sensor messed up. Cleaned with q -tip
and electronic cleaner and all was well. Felt like the originalBatmobile and
it would not pass 2.5 at the tach.
 

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dont have time to read other replies so this may be redundant but it could be a needed tune up or a fuel filter..
 

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Discussion Starter #7
As I said before, I don't think a clogged fuel filter would cause the smoking...and the filter is pretty new. Also, the car was running and then all of the sudden this happened, and its only been a couple thousand miles since the last tuneup. I took the valve cover off, but I didn't see anything unusual. I pulled all the plugs and they were all black and carbon fouled, some with a touch of oil on the outside ring....I cleaned them all and replaced them, but no change. The car will idle now on its own for the most part at a low 400-500 rpms while its shaking and missing and puffing black smoke, and giving it the gas will make it rev up, but still misses and puffs even more smoke. Any ideas? I've never had an engine blow up on me before...does sound like my Z is dead???

Kevin

77 280 2+2
97 Probe GT
02 Altima 3.5 SE
 

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Check the fuel pressure. The fuel pressure regulator may have gone bad. When they go bad they up the pressure at idle to about 60psi, thus doubling the fuel going into the motor and giving you fouled plugs. One way you can check is to clamp the fuel supply line between the filter and the rail. If the car starts off rough but then clears up some then adventually dies this is probably your problem. I suggest getting a new one from Nissan, the three aftermarket ones I got all leaked! Also check the AFM, but my money is on the fuel pressure regulator. Good luck,
Jim
 

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If:
1) the car ran perfectly before this happened
2) this never happened before
3) You didn't do ANYTHING to the car prior to this happening
4) The car didn't get washed, or rained on, or go through a huge puddle or get peed on by a huge dog, or in any other way get wet
5) The battery is healthy
6) the car didn't hit another car, get hit by another car, hit a curb or pothole or take any other large shock load

. . . then I would say this is some relatively simple problem, such as a bad electrical connector. When the engine is idling (bad and low, like you say), get under the hood and give every connector a good wiggle. If nothing changes, get under the driver's dash and wiggle the ECU connector. If that doesn't make any diff (if the motor suddenly speeds up when you wiggle something, then that's the prob), check that the TPS hasn't come loose or gotten wet somehow inside. This is a typical symptom of a wet TPS (throttle position switch). Next, check that your alternator is working. Low voltage would also cause this prob. Next, check — no, remove and clean — your battery terminals, reattach. Try it again.
I suggest these things because again and again and again I read about people buying expensive new parts and putting them in, only to find it doesn't solve their problem. (I've been as guilty of this as anyone else.) My experience is that stuff like fuel pressure regulators and fuel pumps and AFMs don't just "go out," they give plenty of notice over time as they slowly go downhill. Since it sounds like this just happened out of the blue, look for the simple, the obvious the the CHEAP. Then work your way up to the complicated and expensive. Don't worry, more than likely, your Z has many more miles in her. Good luck, and let us know what you find!
 

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Discussion Starter #10
Thanks everyone for the advice so far! I talked to a relative of mine thats more knowledgable than I am about cars and he said it sounded like its running extremely rich rather than the motor being shot. The alternator is working fine, and I did what was suggested above with the fuel regulator.....with the engine barely idleing, missing, and puffing smoke, I clamped the fuel line going from the fuel filter to the fuel rail. Nothing happened for about 2 seconds, then the idle became pretty smooth and shot up to nearly 3k rpm before using all the fuel in the rail and shuting off. I also noticed the black smoke was greatly reduced as well....kinda sounds like this is the problem.....what do you think? If so, is there anyway to temporarily repair the regulator..you know like take it off and clean it up or something until I get a new one?

Thanks,
Kevin

77 280Z 2+2
97 Probe GT
02 Altima 3.5 SE
 

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There really is no temp fix for this. You can try the parts store for one, just check to make sure it doesn't leak. Try Courtesy Nissan out of Dallas, you can probably have them ship you the part to your door for the same price as buying one from a local parts shop. Glad you found the problem,
Jim
 

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hello sounds to me that you having to press the gas peddle down and the fouled plugs that your car is flooding out..running very rich....used to have to floor the peddle on a car i once owned to start it because it would flood at first and blew black smoke untill it got warmed up....michele
 

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Do a search ....

on Johnb510 and Aaron911 and go back 6 months. Lots of great posts about troubleshooting FI Zs.

Problem with connection of one of the temp sensors (most likely connector problem) will lead to full-on "choke" cold temp mixture enrichment. Also, I believe there's a cold start enricher valve on the manifold which is suspect upon rich conditions.

Recomend Nissan OEM for fuel filters and parts.

Good luck!
Al
 

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Discussion Starter #14
Update

Ok, I went back out and looked around again just to make sure it really is the fuel regulator. I pulled the cover off the AFM and wait a min...something doesn't look right. I touched it and wham! I just found out what the problem really was...the AFM flap was stuck wide open! Sooooo...now the crappy idle and smoking went away, but the idle is way high...like 1500-2000 rpms warm even when I turn the idle screw down as far as it goes. I don't know if the AFM going to @!#$ or if I have another problem...and ideas???

Kevin

77 280Z 2+2
97 Probe GT
02 Altima 3.5 SE
 

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Re: Update

glad you found the problem. now check for a vacuum leak that you might have created digging around in there to fix your idle problem.
 
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