2 Questions for 96' 850R

volvrow · Post by **volvrow** » 05 Dec 2007, 20:59

Hi guys,
Haven't posted in a while put had two questions. I am considering using a fuel system cleaner. I don't think I need anything to "harsh" to clean out the system since it is running fine. The manual says not to put additives in the car and just wondered what everyone else does. Is there any special type or brand that anyone would recommend? I am curious if it should be a special product b/c of the turbo?

Second question deals with cruise control. Since I bought the car the cruise control has never worked and I checked the fuses and they are all fine. On the switch the button moves and everything but nothing happens. What might be the culprit and how could it be fixed? I have heard something about a vacuum line that sometimes needs replaced?

Thanks,
volvrow

pccunni · Post by **pccunni** » 05 Dec 2007, 22:30

I just fixed my 97 850 T5 cruise control and it turned out to be the vacuum line that runs from the vacuum pump ( under the battery) into the car. The leak was right under the air cleaner. I just cut the bad part of the line out and replaced it with a piece of rubber tubing . At the beginning of the the 850 forum there is place where you can download a service manual for a 95 850. In the manual there is a very good writeup on the cruise control which I used to troubleshoot my car. Good Luck

volvrow · Post by **volvrow** » 06 Dec 2007, 08:50

Thanks! I will check that out and see if I can find anything. Anyone have any thoughts on fuel system cleaner?

Post by **MadeInJapan** » 06 Dec 2007, 15:18

I wouldn't put very many products in my gas tank to clean the injectors (I suppose that's what you're trying to do). Use high octane fuel and occasionally put Techron in your tank and you'll be good. You can buy the Techron fuel additive at all auto parts stores. Just follow the directions.

Post by **JRL** » 06 Dec 2007, 16:06

MadeInJapan wrote:I wouldn't put very many products in my gas tank to clean the injectors (I suppose that's what you're trying to do). Use high octane fuel and occasionally put Techron in your tank and you'll be good. You can buy the Techron fuel additive at all auto parts stores. Just follow the directions.

That means one can at your oil change, no more

drew525 · Post by **drew525** » 08 Dec 2007, 09:17

Just a thought...are you setting the cruise control correctly. You need to move the switch to on and then to set the desired speed you need to push and hold the button on the end of the arm. I'm sure you probably know but your post "the switch move to on but then nothing" got me thinking.

volvrow · Post by **volvrow** » 09 Dec 2007, 19:55

Good question,
We have another 850 (base model) and can engage the cruise control with no problem. I haven't had the opportunity to check out the vacuum lines. I was looking at the service manual provided on the site here and found that there is a relay underneath the steering column that controls the cruise control, I was going to check that out but not sure how to tell whether it needs to be replaced or not. Its worth a shot at least.

Thanks,
volvrow

pccunni · Post by **pccunni** » 10 Dec 2007, 13:11

The relay you mentioned is the cruise control unit and it is located under the hood with the fuses. Just remove the cover and you will see the control unit. You might chech to see if the one in your other car has the same part number. If you reach under the battery you will find the vacuum hose that runs into the car. Pull the rubber connector off the pump and work it up over the battery so you can blow into the hose. If everything is good, you will not be able to blow into it. With mine I could hear it leaking.

Post by **MadeInJapan** » 10 Dec 2007, 14:51

On mine it was none of these issues. It wasn't until I took the stalk off of the steering column and found a broken wire in the stalk and re-attached it that my cruise control worked again.

volvrow · Post by **volvrow** » 10 Dec 2007, 22:16

Ok,
Thanks for the suggestions- I hadn't thought of switching out the relays from my other 850. I will not be able to work on the car until next week, but I will update with any questions or hopefully solutions.

Thanks for all of your help,
volvrow