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Discussion Starter · #1 ·
Screw it, I hate this fuel injection like the plague. ANyone have a nice set of used SU's and assorted nefarious hardware, so I can make a swap?
Or if any of ya'll have ideas (read the earlier posting), I would appreaciate your input!!
 

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Discussion Starter · #2 ·
> Screw it, I hate this fuel injection like
> the plague. ANyone have a nice set of used
> SU's and assorted nefarious hardware, so I
> can make a swap?
> Or if any of ya'll have ideas (read the
> earlier posting), I would appreaciate your
> input!!

I know where you are coming from. I too have a FI z(78). Believe me I have considered swapping to a carburated setup many, many, many times. Be patient though, you have to go through the normal diagnostic procedures. The early fuel injection was way ahead of its time back then (Nissan didn't know what they had).
Do a semi-thorough tune up and go from there. I read above about cleaning the contacts of all wires(more important than you think, and not to time consuming). Also check the fuel pressure regulator.
I have often thought about jacking with the AFM. If you loosen the main coil spring (to bring in more air) does it cause a misreading to the CPU, and therefore automatically adjusts? Anyone....Anyone.... JN
 

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Discussion Starter · #3 ·
I also have the dreaded fuel injection. Josh is right on. Clean
them connectors! A few months back my '76's temp sensor
was so badly corroded, it would barely run amd would die
espically when hot. Problem is, the
old analog computer reads electrical resistance from most
(or all?) of its sensors. Corrosion causes resistance to go
up thus giving the computer a false reading and causing
(in my case) the engine to run extremely rich.

I think the main advantage of loosening the AFM spring
is to reduce hesitation caused by the AFM's flapper. If
I'm not mistaken, the computer will enrich the air fuel mixture
since more air can enter with less restriction.

ross

> I know where you are coming from. I too have
> a FI z(78). Believe me I have considered
> swapping to a carburated setup many, many,
> many times. Be patient though, you have to
> go through the normal diagnostic
> procedures. The early fuel injection was way
> ahead of its time back then (Nissan didn't
> know what they had).
> Do a semi-thorough tune up and go from
> there. I read above about cleaning the
> contacts of all wires(more important than
> you think, and not to time consuming). Also
> check the fuel pressure regulator.
> I have often thought about jacking with the
> AFM. If you loosen the main coil spring (to
> bring in more air) does it cause a
> misreading to the CPU, and therefore
> automatically adjusts? Anyone....Anyone....
> JN
 

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Fuel Injection Tune-up=19.8MPG

Lynn,
Don't give up on the FI. I have a '77 too and have gone through pure H--- for the last 8 months and gotten as low as 15 mpg and even had times where it wouldn't even run. It basically boiled down to three things.
1) The connectors at the engine temperature sensor and themotime switch and at the point 16 up the leads where they connected into the harness were horribly corroded. Fixed that, put in new, non gas fouled plugs, & mileage went to about 17.8. Took the car to a mechanic with an exhaust gas analyzer who set the AFM and throttle switch to the OEM Nissan specifications and gas mileage went to 19.8. That is a combined city/highway reading while commuting to and from work and on an engine with 166,000 miles and significant damage to rings, bearings and camshaft. Like I said, don't give up, do the above and you'll be amazed.
Phantom
 

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Discussion Starter · #5 ·
Re: Fuel Injection Tune-up=19.8MPG

> Lynn,
> Don't give up on the FI. I have a '77 too
> and have gone through pure H--- for the last
> 8 months and gotten as low as 15 mpg and
> even had times where it wouldn't even run.
> It basically boiled down to three things.
> 1) The connectors at the engine temperature
> sensor and themotime switch and at the point
> 16 up the leads where they connected
> into the harness were horribly corroded.
> Fixed that, put in new, non gas fouled
> plugs, & mileage went to about 17.8.
> Took the car to a mechanic with an exhaust
> gas analyzer who set the AFM and throttle
> switch to the OEM Nissan specifications and
> gas mileage went to 19.8. That is a combined
> city/highway reading while commuting to and
> from work and on an engine with 166,000
> miles and significant damage to rings,
> bearings and camshaft. Like I said, don't
> give up, do the above and you'll be amazed.
> Phantom

Made ran rich so after cleaning all contacts and tightened the afm spring 2 nothes which leaned the mixure up some. Made a big power increase. Gas mileage is about 22 mpg mostly city w/261000 miles on motor way wore out cam and 3.9 diff.

Sam 75 280z
 

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Discussion Starter · #6 ·
Re: Fuel Injection Tune-up=19.8MPG

> Made ran rich so after cleaning all contacts
> and tightened the afm spring 2 nothes which
> leaned the mixure up some. Made a big power
> increase. Gas mileage is about 22 mpg mostly
> city w/261000 miles on motor way wore out
> cam and 3.9 diff.

> Sam 75 280z
Thank ya'll so much for your help. Get this-Yanked the coldstart fuel hose off, plugged it on the intake and fuel side, ripped off most of the smog-borg, and disconnected the brake booster ( the diaphram was leaking) it now revs to 7000 cleanly, and gets about 19 city
 
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