# I smell unburnt gas



## Biscuit (Mar 5, 2005)

I tripped across a good deal on craigslist about a month ago...87 HB with 59k miles for only $650. I have been driving it around and notice that when I am at a stop light I smell that richness in the exhaust. I am getting around 20ish mpg now but I am trying to figure out whats wrong with it. I dont have a check engine light on....which I dont think this truck has one anyways. I noticed that some of the vacuum hoses are SHOT and I also noticed that it wont idle high when cold like normal cars do. I am going to buy the vacuum hose today and get a manual. Hopefully I can get the vacuum hoses replaced and maybe fix this problem. Im sure that everything on this truck is original.


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## TXhwyXE (Dec 20, 2006)

Rubber and plastic parts wear with age whether they are used or not. You might check all fuel line hoses for aging like cracks,also check hose clamps for tightness. This goes for the big hose that goes from gas tank up to where you the filler opening is in the body. 

At some points this truck must have been sitting up for long periods of time. Possibly gas getting old and partially gumming up inside the injectors. Could aged spark plug wiring also be a problem? These problems may just be causing an inefficient burn, raw gas to get through thus poor milage.


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## zanegrey (Dec 5, 2005)

read the codes

and get under there and look..


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## Biscuit (Mar 5, 2005)

I will read the codes if any tomorrow in the day light. I didnt get around to changing vacuum hoses. It runs sooo good and quite and hopefully its just gummed up injectors. I sea foamed the tb and no changes to the unburnt gas smell. Ill run a can through the tank and see if that helps. Im sure that the plugs and wires havent been changed in a while......


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## zanegrey (Dec 5, 2005)

stop doing things that are not related to uburned gas...

just check the fuel line from beginning to end ..

chances are you have a leak in it some where..

usually close to the tank..


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## Biscuit (Mar 5, 2005)

Ok I might have confused yall a little bit. I dont smell the actual gas. Its coming from the tail pipe like its running a little rich. Which is unburnt gas to me. Its not a rotten egg smell....its that smell you get when the car ahead of you just punched it. All the fuel lines are good and nothing is leaking. I am about to go outside and check to see if any codes are available.


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## Biscuit (Mar 5, 2005)

Ok I got a code 12 I think. Then I got a bunch of fast flashing lights. I got 3 fast blinks then 4 fast blinks, then 5 fast blinks and it went back to code 12. I will check them to make sure thats what I saw.


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## zanegrey (Dec 5, 2005)

you turn the key to run position (but not start)
flip the ecm switch on ..as soon as it blinks three times turn the switch off and then rercord the code..


the 1 and 2 and 3 up to 5 blinks are the modes..

you want to be in mode three...

the 12 could make since ..the maf does control the fuel to air mixture..

remove it and see if the wires are broken..

i have mafs for sale...


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## Biscuit (Mar 5, 2005)

Ok here is the description of how I got the codes. 1 slow blink, 2 fast blinks then 3, 4, and 5 really fast blinks. I dont know where the MAF is.


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## zanegrey (Dec 5, 2005)

do you even bother reading what i wrote??


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## Biscuit (Mar 5, 2005)

Excuse the fuck outta me but I cant help I have never pulled codes on a fucking nissan before. I was just trying to make sure I done that shit right.


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## zanegrey (Dec 5, 2005)

persona non gratta...


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