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Discussion Starter #1
Ok guys,
I am going to tell you everything I have done in hopes you can help me with my problem. I am getting ready to go back to the mechanic for the 4th time for the same problem if I cant figure this out. I filled my tank this morning and got 18MPG on the last tank. I went to work and back today and am almost at 3/4 tank and have only been 19 Miles.

I decided to look at some things when I got home today and pulled my O2 sensor out. It is about 3 months old and was BLACK. It looked terrible. I had a spare so I put it in and reset the ECU with the screw. I figured maybe it was black because I had two different injector flushes done in the past 2 months. I took the car for a spin and it felt a little better.

I brought the car home and let it idle for a while. The idle still sounds a little funny and I have a slight misfire. What I found interesting is the car did not have a strong gas smell coming from the exhaust like it always does. I tested the MAF and played with a few hoses. After doing this, I went back and smelled the exhaust again....Pure gasoline.

I tested the MAF volt. Yesterday it was .017 so I regrounded it. Now it is .002.
TPS- .46 closed and 4.01 open
Plugs, Cap, Rotor, Wires, Fuel Pump all new.
No CEL

The car has had 2 injector flushes and the infiniti dealership put it on the computer and tested the injectors. One was clogged, but was free after the cleaning.

What the hell should I do? Why does a car run rich?
 

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P10 FTMFW!!!
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Throw some seafoam through it...then take out your IAC valve and your EGR and clean it all out. helped me get like 5 MPG back.
 

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Discussion Starter #4
P10det....I am about ready to take you up on that offer.

The EGR and IACV and been taken apart twice and cleaned. I am out of ideas.
 

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P10 FTMFW!!!
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Do you drive city or highway mostly? How do you throttle it? Tire pressure? Cleaned teh throttle body? Lots of extra weight in the trunk?
 

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Discussion Starter #6
I put mostly city miles on the car. There is nothing in the trunk and I just took a look at the throttle body...its spotless. I have cleaned that 2X in the past few months.

The gas fumes coming out of the tailpipe are enough to knock you out. Something is throwing off the fuel mixture without tripping a CEL. According to the infiniti dealership, the injectors are fine. The fuel pump seems ok....No vacuum leaks confirmed twice by the consult.

The car is just dumping fuel.


EDIT: A few months ago I was getting 24-25 city miles and 30 highway...I am way off that now.
 

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Discussion Starter #8
No, its not the sending unit. I am actually using this gas. The gas needle is not the problem. Thanks for your suggestion tho. I am going to suck in some seafoam and see what happens. I will put my old sensor back on and some old plugs in the engine.
 

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CH0DEmobile
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This is just a guess/suggestion, but maybe your fuel pressure regulator went bad? I'm not entirely sure if this would cause it to run rich, but it's worth checking.
 

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bhowle said:
This is just a guess/suggestion, but maybe your fuel pressure regulator went bad? I'm not entirely sure if this would cause it to run rich, but it's worth checking.
I would agree with this. Think this out. The only way for the gas to get into the engine is through the injectors so it has to be:

Leaking fuel injectors
Bad fuel pressure regulator
Bad MAF sensor
Bad O2 sensor

Since your car is really dumping fuel I would almost rule out the last two items and look at the first two.
Maybe p10det can give some suggestions.
 

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Discussion Starter #11
Your right. It HAS to be one of those things.

Now, with the service I had at the infiniti dealership a few weeks ago (cleaning the injectors) and the load test they did before and after on them, I assume they are working fine.

Last night I decided to get a bottle of Seafoam and I ran it thru the PVC hose. My god, what a mess of white smoke. It really cleaned a bunch of shit out. I did it again this morning with the same result (ton of white smoke). I took the car out for a drive and it is night and day. The car is MUCH better. I filled the tank again and am going to watch the gas mileage. Maybe some of this carbon was blocking something. Now, I need to wonder....how did it all get there in the first place.

I did test my MAF 2 nights ago and the volt was high (.017). I re-grounded it and now it is back to (.006) or so. So I am guessing, my MAF was telling the computer to dump fuel because it was so "hot" and this extra fuel caused the carbon buildup. Now that I have the MAF right, a different 02 sensor, and a chunk of the carbon out....maybe I will be ok. I could still have a regulator issue, so I need to see how this tank of gas goes. I will tell you this...That seafoam kicks ass. I had fun driving my car for the first time in months. The power is back and the idle was much better.

The one thing that still has me baffled is my timing. It is said that putting the distributor in the middle of the bracket is roughly 15* timing. Well, mine is "advanced" a bit which normally looks like 18-19* but I am reading 16*. My idle screw is just about all the way in...just a small amout off all the way. My car has not always been like that. Could it have anything to do with the upgraded timing chain tensioner that was put on 6 months ago? My chain is INSANE tight when I had the valve cover off last. Sorry this is so long. Thanks for all the ideas guys. It is very appreciated.
 

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P10 FTMFW!!!
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Glad to hear the seafoam helped...i used a 1/3 of the bottle the first time i did it and it helped a good amount. I'm gonna use it again soon once i have some time. But yeah that white smoke is normal...its just all the burnt off crap from the system.
 

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I thought the white smoke was the Seafoam being burned? I did it to my Subaru's IAC once, and I thought it was just because I was pouring combustible stuff through an air passageway...
 

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pauley01 said:
Now, I need to wonder....how did it all get there in the first place.
You may have treated the symptom but not the disease. The carbon may return. If your gas mileage sucks again and you smell gas you know you need to do something else.

pauley01 said:
The one thing that still has me baffled is my timing. It is said that putting the distributor in the middle of the bracket is roughly 15* timing. Well, mine is "advanced" a bit which normally looks like 18-19* but I am reading 16*. My idle screw is just about all the way in...just a small amout off all the way. My car has not always been like that. Could it have anything to do with the upgraded timing chain tensioner that was put on 6 months ago? My chain is INSANE tight when I had the valve cover off last. Sorry this is so long. Thanks for all the ideas guys. It is very appreciated.
Distributor (ignition) and valve timing are two completely different things. So your timing tensioner has nothing to do with your distributor timing. Can't tell from your post if you are using a timing light and the Nissan factory procedure to set your ignition timing. If not, you need to do this properly right away.
Timing chain should be tight.
 

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So pull the plenum, and turn the key on. DON'T start the car. See if the injectors are leaking. 3 of mine were. Got new o-rings, reseated carefully with marine grease and no more leak!

That's if you suspect an injector leak.

Or get a Fuel pressure gauge. You can buy one and make it fit your car for $15.
 

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I don't know, but if this IACV dont fix my car along with all new gaskets, you will be getting my car even if I have to drive to DE.
 
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