| From | Message |
Fed
GenII
 
3/25/2009
18:46:09
|
 Subject: Truck is running poorly
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Message:
Here's how she runs: When cruising at low RPM and you give it
gas (putting the motor under load) she sputters, loses power,
and backfires through the throttle body.
But in the higher RPM she doesn't sputter or pop through the
TB, bust still not all the power is there. Anyway, I've had the
truck at my cousin's shop for over 4 months for him to work on
it for side work and he can't find the problem. He replaced the
cam sensor, crank sensor, head gaskets, and piston rings. I also
had new stainless steel valves put in with new seats. Had them
adjusted and that didn't work. Nothing is wrong with the
computer, I've tried 2 different PCMs. His $10,000 Snap On
scanner can't find anything wrong in the harness or ignition. So
today I paid him for the labor he did and brought the truck
home. Any pointers or ideas of what could be causing this???
1996 Dakota CC 3.9 manual
(9.5:1 CR, cam,1.6 RRs, Tom Fox PCM flash, FMS 24# injectors, K&N FIPK, 50mm ported tb, MSD coil & wires, underdrive pulleys, JBA headers, 4.10 gears w/ limited slip
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?
Dodge Dakota
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3/26/2009
09:17:38
|  RE: Truck is running poorly
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Fuel injector timing = distributor position ?
EGR valve/sensor - I believe 96 still had ?
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no no no
Dodge Dakota
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3/26/2009
20:52:15
| RE: Truck is running poorly
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Message:
bad crank sensor....dealer only...no aftermarket...i had the same problem....bought a autozone crapper....and thats what i got for a cheap price.....
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Da Bumper
Dodge Dakota
JOIN HERE
4/07/2009
14:55:34
| RE: Truck is running poorly
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Message:
Bump
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Fed
GenII
4/07/2009
15:02:16
|  RE: Truck is running poorly
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Message:
thanks mr. bumper but the truck actually began to run A LOT
better. I believe it was the computer learning the new valves,
rings, and newly ported intake manifold. I cut the runners down
to 11" since i'll be turbocharging the motor very soon. Also
removed the divider and opened up the TB bores to 50mm.
The only thing is now it runs lean at part throttle, but at full
throttle all the fuel magically appears. I'm confused about that.
From 1/4 to 3/4 throttle she runs SUPER LEAN from 15.0-17.0:1
Air/Fuel ratio. Any ideas guys?
1996 Dakota CC 3.9 manual
(9.5:1 CR, cam,1.6 RRs, Tom Fox PCM flash, FMS 24# injectors, K&N FIPK, 50mm ported tb, MSD coil & wires, underdrive pulleys, JBA headers, 4.10 gears w/ limited slip
|
well
Dodge Dakota
JOIN HERE
4/07/2009
17:53:24
| RE: Truck is running poorly
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Message:
first thought that came to mind was a slow reacting O2
next thought maybe the tables in the pcm
is it stock, custom flashed or mopar performance?
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Fed
GenII
4/07/2009
23:53:34
| RE: Truck is running poorly
IP: Logged
Message:
pcm is flashed. ran fine before the new valves and pistons and
was on the same flash....
1996 Dakota CC 3.9 manual
(9.5:1 CR, cam,1.6 RRs, Tom Fox PCM flash, FMS 24# injectors, K&N FIPK, 50mm ported tb, MSD coil & wires, underdrive pulleys, JBA headers, 4.10 gears w/ limited slip
|
well
Dodge Dakota
JOIN HERE
4/08/2009
05:10:05
| RE: Truck is running poorly
IP: Logged
Message:
Fed sorry
I just noticed you have the custom flash listed
in your signature
ok moving right along
test the O2
see how it's reacting
possibility it's slow/sluggish
in adjusting the ratio
from there I'd say
Crank, Cam sensor
Fuel inj syn
you also mentioned new pistons
did you raise the compression ratio?
if so how much
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Da Bumper
Dodge Dakota
JOIN HERE
4/08/2009
22:08:33
| RE: Truck is running poorly
IP: Logged
Message:
Bump
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Fed
GenII
4/09/2009
19:25:44
| RE: Truck is running poorly
IP: Logged
Message:
.4:1 I believe. the CR is about 9.5:1
Crank and Cam sensor are new.
O2's are good to go.
1996 Dakota CC 3.9 manual
(9.5:1 CR, cam,1.6 RRs, Tom Fox PCM flash, FMS 24# injectors, K&N FIPK, 50mm ported tb, MSD coil & wires, underdrive pulleys, JBA headers, 4.10 gears w/ limited slip
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Hey fed
Dodge Dakota
JOIN HERE
4/11/2009
20:35:57
| RE: Truck is running poorly
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Message:
did you go colder on the plugs?
ex. rule of thumb
(and you can confirm this with summit or jegs tech)
for each 1.0 you increase compression
you need to go atleast 1 colder with the plugs and in some cases 2 ranges colder
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Fed
GenII
4/12/2009
23:12:19
| RE: Truck is running poorly
IP: Logged
Message:
yes i have 1 heat range cooler on the plugs
1996 Dakota CC 3.9 manual
(9.5:1 CR, cam,1.6 RRs, Tom Fox PCM flash, FMS 24# injectors, K&N FIPK, 50mm ported tb, MSD coil & wires, underdrive pulleys, JBA headers, 4.10 gears w/ limited slip
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J and J Auto
GenII
4/16/2009
01:42:25
| RE: Truck is running poorly
IP: Logged
Message:
heres a thought
If the coil is bad it can crosfire discharging
when its not supose to
timing chain off 1 tooth
You don't have some crap doubble platnum plugs in
there platnum will retain heat and glow
and ignite the fuel during the intake stroke
especialy if its running lean
There is no egr but how about fuel pressure
Larry
J&J Auto
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Fed
GenII
4/16/2009
14:13:25
| RE: Truck is running poorly
IP: Logged
Message:
I will look into that, thanks Larry!
So you can narrow things down more, I tried 2 different coils, no
go :(.
Could a double roller timing chain skip a tooth?! And would the
motor run great at wide open throttle if the timing chain was off
1 tooth? Because she runs great wide open throttle...
Fuel Pressure? I'm beginning to think that's what it is, maybe my
flashed pcm is messing with the part throttle fuel tables. I will
call Tom Fox the guy who flashed my PCM and see if he can
adjust it.
For spark plugs I use NGK FR-5's and Larry I want to get the
BEST plugs possible for N/A and boost...What plug should I get?
1996 Dakota CC 3.9 manual
(9.5:1 CR, cam,1.6 RRs, Tom Fox PCM flash, FMS 24# injectors, K&N FIPK, 50mm ported tb, MSD coil & wires, underdrive pulleys, JBA headers, 4.10 gears w/ limited slip
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J and J Auto
GenII
4/23/2009
05:26:26
| RE: Truck is running poorly
IP: Logged
Message:
the Vpower is what comes with the paxon hemi s/c
kit so I would say you have a good plug
No the chain would not jump but did you recheck
your injector sync
Larry
J&J Auto
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Fed
GenII
4/23/2009
14:48:51
| RE: Truck is running poorly
IP: Logged
Message:
Okay I will have the injector sync checked... I believe you
suggested to have it at +3 or +4 for N/A right? How about when I
run 5psi boost with the turbo? I was told "0" with forced
induction...
1996 Dakota CC 3.9 manual
(9.5:1 CR, cam,1.6 RRs, Tom Fox PCM flash, FMS 24# injectors, K&N FIPK, 50mm ported tb, MSD coil & wires, underdrive pulleys, JBA headers, 4.10 gears w/ limited slip
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Da Bumper
Dodge Dakota
JOIN HERE
4/24/2009
23:12:53
| RE: Truck is running poorly
IP: Logged
Message:
Bump
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Fed
GenII
4/26/2009
22:55:00
| RE: Truck is running poorly
IP: Logged
Message:
Also, it runs more lean and worse when it's cold at start up.
Gradually runs a little better as she warms up.
1996 Dakota CC 3.9 manual
(9.5:1 CR, cam,1.6 RRs, Tom Fox PCM flash, FMS 24# injectors, K&N FIPK, 50mm ported tb, MSD coil & wires, underdrive pulleys, JBA headers, 4.10 gears w/ limited slip
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J and J Auto
GenII
4/30/2009
02:13:29
| RE: Truck is running poorly
IP: Logged
Message:
Its begening to sound like you have a computer
glish
The flash is not right if the o2's are good its
about all that is left
There is something going on there it should
not be running lean
Are you running a fuel managment unit and an
exsilery pump to raise pressure under boost
The injector sync should still be +3 +4 even with
forced induction
Larry
J&J Auto
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Fed
GenII
4/30/2009
08:42:59
| RE: Truck is running poorly
IP: Logged
Message:
Problem solved!!! just yesterday she began to run awesome at part
throttle! the torque is back! Even though part throttle was still a
wee bit lean at 15.0:1, WAY better than 17-18.0:1... It was the
computer learning the newly installed valves, piston rings, and the
ported intake manny would be my guess. I also installed new Comp
Cams stainless steel 1.6 roller rockers, studs, and poly locks (I
doubt that had anything to do with it) But thanks for your time
Larry and everyone else!
1996 Dakota CC 3.9 manual
(9.5:1 CR, cam,1.6 RRs, Tom Fox PCM flash, FMS 24# injectors, K&N FIPK, 50mm ported tb, MSD coil & wires, underdrive pulleys, JBA headers, 4.10 gears w/ limited slip
|
well
Dodge Dakota
JOIN HERE
4/30/2009
11:01:36
| RE: Truck is running poorly
IP: Logged
Message:
Hey right on Fed!
Hope it all works itself out, Thanks for the update too. (I allways look forward to them)
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