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Discussion Starter · #1 ·
I'm getting intake backfire when I am at an idle and I punch it quickly.
It did it before the tuneup but I just gave it a tune up and the timing is where it should be.
There also seems to be a little hesitation before it revs up.
Any ideas. Joe...
 

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Apparently the mixture you are getting is lean, has sombody messed up with the Air Flow Meter?
Another possibility is a vacuum leak.

CarlosZXT

> I'm getting intake backfire when I am at an
> idle and I punch it quickly.
> It did it before the tuneup but I just gave
> it a tune up and the timing is where it
> should be.
> There also seems to be a little hesitation
> before it revs up.
> Any ideas. Joe...
 

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107,695 Posts
Discussion Starter · #3 ·
> Apparently the mixture you are getting is
> lean, has sombody messed up with the Air
> Flow Meter?
> Another possibility is a vacuum leak.

> CarlosZXT
I had it out once, I can't remember why but i do rember breaking off a little piece of the the edge of the plastic cover and i had to patch it with some sealant.
I guess I should just look for a new one, this is the original one.
I hear the rebuilds don't last?
 

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If you broke a piece of the cover you DONT have to get a new AFM. no way!
what I tried to say is that if someone messed with the tension of the flapper valve then they changed it the wrong way (increased tension instead of reducing it) and that you should adjust it properly

Z-ya

CarlosZXT

> I had it out once, I can't remember why but
> i do rember breaking off a little piece of
> the the edge of the plastic cover and i had
> to patch it with some sealant.
> I guess I should just look for a new one,
> this is the original one.
> I hear the rebuilds don't last?
 

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62 Posts
> If you broke a piece of the cover you DONT
> have to get a new AFM. no way!
> what I tried to say is that if someone
> messed with the tension of the flapper valve
> then they changed it the wrong way
> (increased tension instead of reducing it)
> and that you should adjust it properly

> Z-ya

> CarlosZXT
Hey Joe, I have had the same problem with my 80 280zx, among other problems, but that was one of them, a mechanic that I had taken my car to put in a different computer than the one that was in there, cause I had told him that I didn't think that the present one was the correct control unit, so he threw a different one in real quick, and presto, no more backfire, so it's possible it has something to do with your control unit, and If you do try to fiddle with the AFM, goodluck, I spent much time with mine to no avail, those little boogers are nutz...but, when I was working on mine, my car had mucho other problems at the same time, so, I can't really blame the AFM, good luck, I know what your going through..
 

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Joe,
Pull a couple of your plugs. Are they:

white - lean

tan - OK

black - rich
If they are something other than black then you need to review what you adjusted that could cause the engine to run lean or rich. At least you'll have a general problem area to pursue.
If they are running tan then your mixture is OK and it's another problem.
What is your idle set at? Up it 100-200 RPM and see if that helps. Valves adjusted in the last 15,000 miles?
List goes on. Give these a shot. Good luck.
Phantom
 

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Discussion Starter · #7 ·
> I'm getting intake backfire when I am at an
> idle and I punch it quickly.
> It did it before the tuneup but I just gave
> it a tune up and the timing is where it
> should be.
> There also seems to be a little hesitation
> before it revs up.
> Any ideas. Joe...

Try putting a 300 ohm resistor inline with the engine temperature sensor (not the temp guage sensor) and see it the problem goes away. If it does then you have a bad spot on the AFM variable resistor.. Cheap to try...
 
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