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htandmces86
Dodge Dakota
JOIN HERE
8/19/2010
16:53:17
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 Subject: setting injector syn on a 97
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Message:
looking to gain knowledge on how to do this i have a 97 3.9l just rebuilt the motor and now hoving some issues with idle searching while in park and neutral then dies as soon as i put it in drive
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jandjauto
GenII
8/19/2010
23:38:00
| RE: setting injector syn on a 97
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Message:
Do a serch its the same on all the dak 3.9's
+3 is where they run the best
Larry
J&J Auto
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Jonas
Dodge Dakota
JOIN HERE
8/20/2010
17:23:49
|  RE: setting injector syn on a 97
IP: Logged
Message:
Message:
I will explain how to do it
Always turn the crank clockwise never go bacwards
if you pass up the mark you will just have to
keep going in the same direction
1 1/4 or 32mm socket
Put vibration damper on 0 TDC the rotor will be
aiming towards the pass side of truck right near
the #1 plug wire
On the G2 trucks like ours it eaiser to see than
the G3 were the engine is moved back and under
they are a pain and you need to use a mirrior
So 0 TDC
from the front of the truck looking back
look straight down over the rotor with a good
light.
always just push the rotor with light finger
pressurer counter clockwise this will take out
any little play in the cam gear just a light
push don't try to force it, you will see on any
vehicle that you can slightly turn the rotor
back and forth this slop needs to be out to get
it set more acurate
There is a line marked cyl on the pickup in the
dist this tells the injectors when to fire
With the rotor button centered over this line
that is 0
They come from the factory anywhere from -3 to 0
the techs are told not to set past 0 but they run
best with the stock cam at +3
With your cam I would go +5 +6 just like I did
OK
looking from front if you turn the dist counter
clockwise this advances the sync clockwise
retards the sync
from front the back edge of rotor button with
cyl line this is +3 the back edge of rotor button
the side closesest to you of button
move this back edge aprox 1/8 past line this will
be +6
the hole button will be behind the cyl line
looking from the front
Setting them this way you will be within +- 1
The instructions that most use is to put it on
TDC than rotate the dist back and forth until you
see a 5 volt jump than tighten
This is crap and you can be off +- 5 doing it
this way
I ran mine at +3 with the stock cam the intake
opened 8 degreed befor TDC and the injector was
fireing at 6 degrees
My new cam opens 12 degrees before TDC and I have
the sync at +5 which will fire the injectors at
10 before TDC
Helps everything having this right throttle
response power and gas mileage
As soon as that valve cracks open there is a
scavaging effect going on and the exhaust flow
is actualy helping pull in some of the fuel
once the valve is open farther and the exhaust is
now closed your just relying on the piston
down travel to draw in fuel
catching this scavaging effect will more
effeciently fill the cyl's getting a bigger
charge in there besides creating more power
also will help the cyl temps stay down
When they are set at 0 or on the - side
fireing the injector late you miss the spray
when the scavaging is going on power and
response will suffer
It can make a big diff especialy with a hotter
cam opening soone and more overlap where both
valves are open at the same time
I am running a 30 degree overlap on this cam
almost same as stock but the duration is 6 degrees
more intake side and 8 on the exhaust side
The stock cam also has a 114 center on intake
side this cam 112 so right there your opening the
intake sooner and you must compensate for
that by changing the injector sync if you have a
hotter cam and set the sync stock the motor will
be very flat in performance
KRC Performance is recomending anywhere from
+6 to +10 for the hotter cams yours should work
well at +6
Larry
J&J Auto
Message:
There is a line scribed on the lip of the distributor housing that you'll see when you take the cap off. With cyl #1 at TDC, the rotor tip should be exactly centered on it (factory spec, but often they are slightly misadjusted). For slightly better performance and gas mileage, rotate the distributor body (loosen the hold-down bolt) and rotate VERY slightly, until when you are facing the vehicle from the front, the trailing side of the rotor (instead of the center of the tip) lines up with the mark on the dist housing. This should be about 3 degrees of rotation. If you go too far, the truck backfires and runs badly. Also, there might be some slop in the timing chain that will affect the accuracy, so adjust it in tiny increments.
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htandmces86
Dodge Dakota
JOIN HERE
9/01/2010
10:19:26
| RE: setting injector syn on a 97
IP: Logged
Message:
so I'm not sure if i went too far or not enough, but the truck seems to idle search while in park and neutral, while in reverse or drive if i don't keep my foot on the throttle it wants to die out, and while driving it backfires from time to time, any thoughts?
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daddio
Dodge Dakota
JOIN HERE
9/01/2010
13:26:27
| RE: setting injector syn on a 97
IP: Logged
Message:
The surging idel could be from the IAC on the back of the throttle boy or the TPS. Check for codes. And since it's backfiring, you could have gone a little too far with the sync.
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