Vacuum line disconnected...what is it?
#1
10-21-2010, 03:41 AM
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Vacuum line disconnected...what is it?
My truck runs good cold, but will not accelerate at all when hot. I have replaced most of the sensors, etc. I just found this vacuum line not attached to anything...could this be the problem and what is it for? Can I just plug it? It comes off the bottom of a "T" along the upper firewall on the passenger side.
1999 Dakota 5.2 4x4 automatic
1999 Dakota 5.2 4x4 automatic
#2
10-21-2010, 06:51 PM
Well,,,after looking through my digital manual, I find a diagram that shows the line coming off of that tee going to the SPEED CONTROL SERVO.
Does your truck have cruise control,,,and is it working?
If you don't have cruise control, I would just plug it and see what happens. If nothing else, you will eliminate a vacuum leak.
Does your truck have cruise control,,,and is it working?
If you don't have cruise control, I would just plug it and see what happens. If nothing else, you will eliminate a vacuum leak.
Last edited by pileit1; 10-21-2010 at 06:57 PM.
#3
10-22-2010, 01:38 AM
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#5
10-22-2010, 06:59 PM
I'm 100% sure thats the vacuum line for the Cruise control unit, if you have cruise control and want to use it you will have to replace the brittle vacuum line very cheap, or you can remove the cruise control unit and lines and plug the vacuum line (this is what i did with mine) and everything will be fine.
#6
10-23-2010, 03:57 PM
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#7
10-24-2010, 03:49 AM
Giving up is for women. When your truck warms up it goes from open loop to closed loop, meaning instead of the pcm getting readings from the o2 sensor it is dumping fuel to warm the motor up, when it reaches temp the pcm receives readings to adjust the fuel via the pre cat o2 sensors, if the truck is running like **** when it reaches temp it can be a few things. Your o2 sensor are bad, you have a short, or the map sensor/pcm is bad. I would suggest checking the pcm for saved codes and see if any codes show up if you have a cel if you dont have a cel check it anyways it saves old codes, and sometimes does not toss cel light.
I would start with the cheapest part to replace and work your way up or if you have a friend with the same truck you can swap sensor and check.
If i had to guess i would say depending on how many miles you have on the truck and the last time you changed the o2s, im guessing the o2 sensor, (pre cat) before cat.
I would also check for any other vacuum leaks, if the cruise control unit broke due to be brittle then that probably means that the other vacuum lines are shot to, you can replace the whole vacuum lines in our truck for dirt cheap.
I would start with the cheapest part to replace and work your way up or if you have a friend with the same truck you can swap sensor and check.
If i had to guess i would say depending on how many miles you have on the truck and the last time you changed the o2s, im guessing the o2 sensor, (pre cat) before cat.
I would also check for any other vacuum leaks, if the cruise control unit broke due to be brittle then that probably means that the other vacuum lines are shot to, you can replace the whole vacuum lines in our truck for dirt cheap.
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#8
10-24-2010, 05:06 PM
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Giving up is for women. When your truck warms up it goes from open loop to closed loop, meaning instead of the pcm getting readings from the o2 sensor it is dumping fuel to warm the motor up, when it reaches temp the pcm receives readings to adjust the fuel via the pre cat o2 sensors, if the truck is running like **** when it reaches temp it can be a few things. Your o2 sensor are bad, you have a short, or the map sensor/pcm is bad. I would suggest checking the pcm for saved codes and see if any codes show up if you have a cel if you dont have a cel check it anyways it saves old codes, and sometimes does not toss cel light.
I would start with the cheapest part to replace and work your way up or if you have a friend with the same truck you can swap sensor and check.
If i had to guess i would say depending on how many miles you have on the truck and the last time you changed the o2s, im guessing the o2 sensor, (pre cat) before cat.
I would also check for any other vacuum leaks, if the cruise control unit broke due to be brittle then that probably means that the other vacuum lines are shot to, you can replace the whole vacuum lines in our truck for dirt cheap.
I would start with the cheapest part to replace and work your way up or if you have a friend with the same truck you can swap sensor and check.
If i had to guess i would say depending on how many miles you have on the truck and the last time you changed the o2s, im guessing the o2 sensor, (pre cat) before cat.
I would also check for any other vacuum leaks, if the cruise control unit broke due to be brittle then that probably means that the other vacuum lines are shot to, you can replace the whole vacuum lines in our truck for dirt cheap.
There are no codes. I changed the upstream O2 sensor already, tps, coolant temp sensor, air charge temp sensor, coil, took the catalytic converter off, swapped out the map and iac sensor with a friends, checked the plugs/wire/rotor/cap....that is all I can think of right now.