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Discussion Starter #1
Hi All,


Last week I replaced my fuel injectors. All went well except for a leak on the #3 injector. So parked the car, pulled the fuel pump fuse and tried to start the car in order to relieve the fuel.


That was Monday. I went out tonight to see if more injectors was were leaking. When I started the car it had a real bad ilde....worse than with the old injectors. It also had a strong gasoline smell which came from the exhaust along with white misty smoke. I could see drops of gas on the ground. hmmmm! That did not happen before.


I plan to break it down again to fix the leak....however it looks like I might have a new problem. Injector gone bad or air in the fuel line or something.

I look forward to your experienced input.


old90
 

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Most likely you have a bad injector. The same thing was happeneing to my 89 Max. I replaced the faulty injector and it stopped. Check all of them because more than one could be bad, esp if the gasoline smell is strong.
 

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Discussion Starter #5
old90 said:
Hi All,


Last week I replaced my fuel injectors. All went well except for a leak on the #3 injector. So parked the car, pulled the fuel pump fuse and tried to start the car in order to relieve the fuel.


That was Monday. I went out tonight to see if more injectors was were leaking. When I started the car it had a real bad ilde....worse than with the old injectors. It also had a strong gasoline smell which came from the exhaust along with white misty smoke. I could see drops of gas on the ground. hmmmm! That did not happen before.


I plan to break it down again to fix the leak....however it looks like I might have a new problem. Injector gone bad or air in the fuel line or something.

I look forward to your experienced input.


old90


I found out what the problem was. The #4 injector was stuck open. I was able to squeeze the fuel line and hear gas gooshing from the engine block. When I removed the fuel rail gas was running from the #4 injector. I was able to replace it and try again. Same problem from the 1st post. I'm done with re-manufactured injectors. The next set will be brand new.

old90
 

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Discussion Starter #6
I started trying to fix the problem again. I checked the fuel pressure got this:

48 psi @ idle
55+ psi @ when I pushed the gas peddle or fuel pressure valve vacuum hose is removed.

The chilton book says that it should be 36 psi @ idle and 43 psi with fuel pressure valve vacuum hose removed.

This time when I removed the injectors none them were leaking/dripping gas.

I did change the fuel pressure regulator when I changed the bad #4 injector.

My questions are:

Is it possible that I got the wrong regulator?

What else could a the pressure to go that high?

Do those number from the chilton book jive the numbers in the Nissan factory service manual for a 90 maxima?

Thanks for all of your input,

old90
 

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Those are the correct pressure numbers. I have a gauge in my car and it runs 38psi at idle, and low 40s under throttle.
My nissan manual says 36-39psi at idle and ~40-43 under throttle.


you might try just blowing some air or something through your fuel return line and see how much pressure it builds up. it might be corroded, pinched, clogged, etc somewhere along the line.
also make sure there's no kinks in the return line as well. even if it's a small kink, it can cause a couple psi pressure backup, and then the fuel pressure regulator will add 38psi to it, causing it to be above spec.

good luck
 

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Discussion Starter #8
I just finish putting the old regulator back on. The pressure is at 40 psi and the car runs better. It runs like it did BEFORE I changed the injectors. Oh well...so much for the dealers diagnosis.

I noticed light smoke coming from under the manifold or someplace. I saw more as I increased the rpms....hmmmm.

I think at this point I will take to my shop. They may be quicker finding the problem.
 

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Some of that may just be steam off the coolant or whatever under the manifolds when the engine gets hot..

good luck man.. sorry you're having so many problems with it!
 

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I ran into the same problem.....be sure you lube up the fuel rail with some vasaline or something like that...when you insert the injector in the rail, it is a tight sqeeze on the small O-ring on the injector....I was using motor oil but was not doing the job, so I used alot of vasaline and had no more problems with engine flooding.
40+ lbs is a lot of pressure...if there is a slight tear or deformity of the O-ring, fuel will get by the injector, thus dumping fuel in the cylinder(s).
 

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Discussion Starter #11
I Guys,

I think I got. I removed the injectors and this time I put vaseline on the top and bottom o-ring like you guys suggested. The injectors went the rails smoothly, easier than with motor oil.

When I first installed the injectors, I did not put any oil on the small o-rings. So that was part of problem.

My fuel pressure is still at 40 psi. That might be another problem, even from before I bought the car ( I'm the second owner).

So right now no gas and white smoke coming out of the exhaust. I might have to check the gaskest or something because I see what looks like exhaust smoke coming from the engine area. I might have to let the excess fluid burn off .

Once again thanks for all the input. The vaseline on the o-rings is definitely a pro tech tip.

old90

Next I want to modify the air intake. Any suggestions....? :)
 

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Smoke in the engine bay is normal for a few days, give it some time and watch it. On the intake bit, what i did (i don't feel like dropping 150 for an intake) is cut the plastic past the mass air flow sensor and clamp a cone filter on. It's easy and cheap. I would suggest getting a K&N cone or AEM, make sure it's name brand and reuseable, and later (or now if you feel like it) get piping to go from the throttle body to the mafs and from the mafs to the fender for colder, better air.
 

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Don't waste your time with a CAI. when the car is moving, there's wnough air flowing in the engine bay that it doesn't make a difference. I think there's actually a bit more power on my car after I removed the CAI. I certainly like the sound better.

on the smoke issue, it sounds like you need to just let it burn off a bit first. when you get oil in the exhaust, it can take easily a half hour of driving before it cooks it all off (and hope you don't clog your cat with soot!). once it's clean again, then you should be okay.

these cars are also known for broken exhaust manifold studs, and that could be where your leak is coming from under the hood.. If it ticks horribly when it's cold and goes away after a few minutes of driving, that's the easiest sign.. also if your exhaust is smoking pretty bad (like after you've done work and the intake/exhaust is full of oil), you can watch to see where it's coming from.. stick a small fan in there to blow it away from your face, and you should be able to stick your head around the sides and see where the smoke is coming from.
 

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Discussion Starter #14
Matt93SE said:
Don't waste your time with a CAI. when the car is moving, there's wnough air flowing in the engine bay that it doesn't make a difference. I think there's actually a bit more power on my car after I removed the CAI. I certainly like the sound better.

What's the CAI?
 

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CAI = cold air intake
aftermarket intakes come in a couple types..

WAI (warm air intake), which is usually just a pipe- commonly called a midpipe- and an adaptor for a cone type filter to plug into.
You can see it in this pic:
http://mattblehm.com/pics/car/powdercoating/100_0237.JPG

and CAI (cold air intake). This one has the same parts as above, but also includes a pipe that runs into the fender well or somewhere else outside the engine bay and puts the filter there. that way you're supposedly sucking colder air in and gaining power from the cooler air.
Here's a shot of mine with the battery removed:
http://mattblehm.com/pics/car/drivetrain/CAI/disk2/MVC-003S.JPG
The filter goes in the fender well, just behind the front bumper (note the plastic liner is still removed from the install):
http://mattblehm.com/pics/car/drivetrain/CAI/disk2/MVC-004S.JPG
 

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Discussion Starter #16
Hmmm.....interesting. I will explore that. As far as the smoke, I drove the car around and it burned off excess stuff and settled down real well. I drove the car to work and it is running smooth again.

Once again thanks for all of the advice.

old90
 

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stats?
uhhh.. you don't wanna know. :)

'93 SE.
218,000 miles. original engine. never done more than replace a valve cover gasket and change the oil.
mods? you name it, I got it- or I'm working on it. ;)
http://www.mattblehm.com/pics/car/
you can poke around there, or just poke around my webpage for some of the parts I've made well enough that they're worth selling.
http://www.mattblehm.com
 
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