| From | Message |
BDE
Dodge Dakota
JOIN HERE
1/22/2004
20:30:36
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 Subject: 99 engine problems
IP: Logged
Message:
Have a 99, 3.9,4x4
The 3.9 isnt the smoothest running engine at the best of time,small surges in RPM are
noted at idle all the time ,but should cause no real performance problem.
My truck would hesitate,ping,backfire and stall.
Only when it was below freezing,and only after it warmmed up.The fault code was
"intermittant cam or crank sensor"
The 3.9 uses both the cam and crank sensors to set fuel injector pulse and timeing.
The engine computer also runs in a open and closed loop,During warm up(open loop) a
limited number of sensors(about 10)are used with a pre set program in the computer.
After warm up(closed loop) the computer takes inputs from more than 12 different sensors.
The system also uses a "data bus" that uses one wire to carry many different signals at
the same time.
Any hicup in a sensor, or the main engine computer ,or the order it gets it information from
the data bus and the system gets confused.It will adjust the wrong thing at the wrong time
thus your engine runs like crap.
Dose anyone know if the PCM should default to the preset(open loop)program and run
correctly if a problem is sensed.Or did the morons that designed this night mare figure
nothing would ever go wronggggggggggggggggggggg??????
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another mark
Dodge Dakota
JOIN HERE
1/22/2004
20:54:55
|  RE: 99 engine problems
IP: Logged
Message:
Hey, since your aren't going to do this deal anymore can you pass along the contact info to someone else to do the next group buy? I can't afford it this time around and there's no way in hell I would pay the actual retail value of one of these things. But for $270 I would.
Thanks
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another mark
Dodge Dakota
JOIN HERE
1/22/2004
20:55:42
| RE: 99 engine problems
IP: Logged
Message:
Sorry, wrong thread.
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J and J Auto
GenII
 
1/23/2004
02:06:08
| RE: 99 engine problems
IP: Logged
Message:
It depends on what sensor or troble code comes up
depending on which one yes it will go into open
loop and run on default tables.
You could have a lazy sensor not bad enough to
trip the mil light (malfuction indicater light)
Check these sensors you can find a thread telling
you how by putting the word "table" in the search
IAT incoming air
Engine temp sensor
TPS throttle position sensor center wire & ground
.35 to .75 volts.
Check your IAC idle air control selonoid clean
with carb cleaner may have carbon build up
check all the connections on the pickup in the
dist and the crank sensor.
You can put the truck in limp mode to run on
default tables have the truck running and unplug
the IAT sensor and it will go into open loop and
run on the default tables and also give you a code
for IAT voltage to low
Larry
J&J Auto
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BDE
Dodge Dakota
JOIN HERE
1/27/2004
21:34:57
| RE: 99 engine problems
IP: Logged
Message:
If you trick it to run in "limp mode" will it damage anything? Is there a time limit ? or is it a get home only thing?
This is exactly the info I wanted
Thanks
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