Nissan Forum banner

1 - 20 of 20 Posts

·
P.O.S. Truckdriver
Joined
·
2,070 Posts
Discussion Starter #1
i ran at the strip tonight and my friend said while i was making my pass i had black smoke coming out of my tailpipe when i would shift. he's pretty knowledgable about cars and said it was probably carbon buildup. is this the reason or could there be other alternatives? he also told me to put some 110 octane race fuel in and it would burn off the deposits. any help is appreciated.
 

·
Registered
Joined
·
638 Posts
Get a bottle of STP complete fuel system cleaner, it will clean up any carbon build up in your fuel system. I use a bottle once a year works great. It doesn't contain any alcohol so it won't corrode or hurt your fuel injectors like some of the other cleaners out there. BTW 110 octane racing fuel is expensive and can damage your converter...
 

·
P.O.S. Truckdriver
Joined
·
2,070 Posts
Discussion Starter #3
so it probably wouldn't be carbon buildup on my pistons? i dont see how that could happen though, since ive always used 93 octane. the 110 octrane gas is $3 a gallon or 3.99 a gallon..it really wouldnt matter if it did anything to my converter though...since we don't have emissions tests in SC. i will give the fuel system cleaner a shot first before i spend an ungodly amount on gas.
 

·
Tuner/Mechanic
Joined
·
266 Posts
you should check sentra.net for combustion chamber cleaning. this is VERY effective. i did it on my b13 about 2 months ago, totally different motor. anyway, if you do put 110 octane in your car, don't put more than 1/3 a tank, or else it might detonate, or could really damage your motor!
 

·
DNE's VZR Conversion
Joined
·
6,079 Posts
another alternative is that you can go pay like 40 bux and get Z MAX kit. You can get it at any kragen. pepboy and autzone stores. I had a buddy use that on his 96 Galant and his engine inside is like brand new lookin.
 

·
Former SuperMod
Joined
·
745 Posts
FWIK, the discussion about fuel injector cleaner (if this relates to your problem...) and Nissans is that they don't go together. Nissan fuel injectors are very sensitive, and running fuel injector cleaner *could* damage them. Food for thought.

Also, does that Z-MAX stuff actually work? Heard it was a rip off. I'm not about to start dumping fluids into my system to see if they work...
 

·
DNE's VZR Conversion
Joined
·
6,079 Posts
the Z-MAX stuff does work. I saw the inside of my friends car and it was freakin clean ! and his car has like 96000 miles on it.
 

·
Driver
Joined
·
736 Posts
I don't know about Zmax fuel additive, but the oil additive was checked out by a local news channel and was found out to be nothing but mineral oil. Make of it what you will.
 

·
Former SuperMod
Joined
·
745 Posts
I'm with you barnoun, yet again. I'm not against anyone using ZMAX or any products similar to that. As I stated I have been informed in the past by very knowledgable sources that fuel injector/system cleaners *can be* harmful to our motors, as well as the SR20DE. As for the oil additive, I question how well it works when I can find it at the mall in the "As Seen On TV" store.

Liuspeed... I am happy your friend's motor is running and looking much better.
 

·
DNE's VZR Conversion
Joined
·
6,079 Posts
As for the oil additive, I question how well it works when I can find it at the mall in the "As Seen On TV" store.
the Z-max thing i found it at the local pep boys , kragen and autozone.
 

·
P.O.S. Truckdriver
Joined
·
2,070 Posts
Discussion Starter #12
alright guys..i'm going to use the combustion chamber cleaner tomorrow since it's my day off. i posted the same question on the sentra performance mailing list and someone said the black smoke could be caused by my car running very rich. what is everyone's opinions on this? just trying to get as many possibilities for the problem as i can. thanks.
 

·
Registered
Joined
·
87 Posts
when i wash my car there is a little bit of black soot on the tailpipe. i think i may be running rich. fuel economy doesn't seem that great. what can i do to fix it. sensors, maybe?
 
Z

·
Guest
Joined
·
0 Posts
Katana200sx, you saying that black smoke was coming out WHEN YOU SHIFTED gears.This condition occures when you snap throttle closed after it has been at WOT(e.g. change gears).The reason is that when car runs flat-out, it consumes heaps of fuel and air (as mesured by airflow meter),to maintain correct air/fuel ratio.When you snap throttle shut,air is still travelling in your intake system at high speed (because it has inertia) ,past airflow meter(which still registers it) and stacks onto closed butterfly in the throttle body.In other words,the moment you lift off the gas and throttle shuts there is only a fraction of air available to the engine compared to the amount of air at WOT.But since airflow meter still thinks that you are going flat-out (because air still rushes past airflow meter for a few tenths of a second even after throttle is shut) it tells the ECU to dump full load worth of fuel wich results in momentary super-rich A/F ratio.
This is NORMAL.Nothing to worry about.
Hope you can make sence of this post since its a bit technical and a bit long.
Cheers
 

·
Driver
Joined
·
736 Posts
zhecka

That's a good idea, and I can relate because I've noticed black soot on my exhaust since I started autocrossing(lots of WOT). I was starting to get concerned with all this running rich commentary, but I'm relieved now:D
 

·
P.O.S. Truckdriver
Joined
·
2,070 Posts
Discussion Starter #17
zhecka,

thanks, yes it makes perfect sense to me. especially since no one has ever told me about the black smoke until that night when i tried seeing what my time was by shifting off of the rev limiter.
 
Z

·
Guest
Joined
·
0 Posts
O2 Sensor

I am sure this has already came up but O2 sensor's role in life is to help with fuel econome under CRUISE condition.The moment the car is at WOT,ECU switches onto PRESET values programmed into it.O2 sensors in good/bad/missing altogether condition do not affect your performance at WOT one bit.
 

·
Sentra Flogger
Joined
·
108 Posts
zmax

more food for thought, these excerpts from the federal trade commission web site. read it and weep, boys and girls:

"The Federal Trade Commission has filed suit in U. S. District Court seeking to halt false and misleading advertising for zMax auto additives and has asked the court to order refunds to consumers who bought the products. The agency alleges that enhanced performance claims for the product are unsubstantiated, that tests cited to support performance claims actually demonstrated that motor oil treated with zMax produced more than twice as much bearing corrosion than motor oil alone, and that the three different products - an engine additive, a fuel line additive and a transmission additive - were all actually tinted mineral oil..."

"... According to the FTC complaint, since at least May 1999, zMax ran infomercials touting its "Power System," a $39 package of three additives to be used in the engine, fuel line and transmission of automobiles. The infomercials feature testimonials from consumers and race car drivers making claims such as, "I was averaging about 22 miles to the gallon on the highway. I installed the zMax and so I jumped right up to about 28 miles per gallon;" and "zMax guarantees a minimum of 10 percent gas mileage increase." Other marketing and promotional pieces claim, "zMax with LinKite has the scientific, CRC L38 proof it takes your car to the MAX!" and "Why zMAX Works - Cuts carbon build-up on valve stems 66%; Lowers wear on valve stems 66%; Lowers wear on piston skirts 60%; Reduces blow-by leakage 17.7%; Increases combustion efficiency 9.25%; Lowers fuel consumption 8.5% - Results of an independent CRC L38 test."

"According to the FTC, the CRC L38 test is a standard auto industry tool to measure the bearing corrosion protection properties of motor oils. In February/March 1997, an independent laboratory performed two CRC L38 tests of zMax for Speedway and Oil Chem. In those tests, motor oil treated with zMax produced more than twice as much bearing corrosion as motor oil alone. The complaint also states that the defendants fabricated one "report" from the two test reports, eliminating the bearing corrosion results and all other negative test results, and then used that report and the "official laboratory results" - similarly edited to remove detrimental data results - as sales tools in the infomercial and on the zMax Web site..."

"... This case is the latest in a series of FTC law-enforcement initiatives targeting unsubstantiated claims made by auto additive manufacturers. The FTC previously halted allegedly deceptive advertising by the marketers of Dura Lube, Motor Up, Prolong, Valvoline, Slick 50, and STP, other major brands of engine treatment products..."
 
1 - 20 of 20 Posts
Top