A/C overcharged? high engine load, increased running temps, stalled...thx for input - Page 7 - PeachParts Mercedes-Benz Forum

sshanky · #91 06-23-2011, 09:47 PM

I'll read the sticky lol. I don't know if I can satisfy the fan requirement...I wonder if I can find something. How about a big square house fan or a shopvac set to leaf blower mode? I don't know how to get the ac on high but the blower on low. I have the pushbutton controls (old ones) so I do have auto-hi and auto-lo modes. I imagine auto-lo would do the trick. I've straightened some of the fins but I will check them all. The cowling is all in place.

leathermang · #92 06-23-2011, 10:03 PM

Max cool, blower low.
Do not trust auto-lo.
Since you are having problems.... you might need to borrow a good fan...
the air over the condensor is the bottleneck of all AC systems.....
If that is not sufficient it can screw up your diagnosing...
In fact i believe that is one of the situations where when using the sight glass to fill the refrigerant it can cause a false ' add ' signal... causing all sorts of other problems..

How about the fins INSIDE the evaporator being cleaned before you start any of this other stuff ?

This would be about the minimum...
http://www.northerntool.com/shop/tools/product_200007224_200007224

sshanky · #93 06-23-2011, 10:05 PM

ok, time to search for a fan. Meanwhile, if i put it on auto-hi, the fan will be on hi. if i put it on auto-lo, the fan will be lo. which one should i use? either way the compressor stays on.

engatwork · #94 06-23-2011, 10:05 PM

Quote:

Finally, they told me they increased the idle.

I'd find another mechanic. I hope they did not screw around with your injection pump. Sounds like they are trying to make it work in 110+ dF heat using r134 in a system designed for r12. I hate to say it but the system is probably doing about as good as it will do with r134.

leathermang · #95 06-23-2011, 10:10 PM

LOL, I assumed he has accepted that HE needs to do what is done to get it done correctly...

leathermang · #96 06-23-2011, 10:13 PM

I only have books and smarts enough to deal with the type one AC in MB... you will need to figure out how to get max cold and LOW blower combination... the air needs to be going across the evap fins slow to gauge the temperature it is reaching... and the unit as a whole needs to be working full to take in and spread around the refrigerant to give accurate readings and reactions..

sshanky · #97 06-23-2011, 10:16 PM

Well, it was actually quite cold, other than the stalling problem...now I wonder if it's as cold. I don't think so.

How did he adjust the idle? I would like to know if he played with the IP. I actually did play with it once myself. I adjusted the rack damper bolt with good success a few months ago to eliminate most of the engine shaking at idle and low rpms. But I never played with idle.

sshanky · #98 06-23-2011, 10:17 PM

Leathermang, I think that in this old system, auto-lo does the trick. the compressor stays on, and the fan just gets lower. the air usually gets colder when i do that.

leathermang · #99 06-23-2011, 10:20 PM

Quote:

Originally Posted by sshanky

Leathermang, I think that in this old system, auto-lo does the trick. the compressor stays on, and the fan just gets lower. the air usually gets colder when i do that.

Ok.. just make sure the windows are open... so it is working all the time you are messing with it...I was worried about the ' auto' being able to sense something and decide it was ok to cycle or something...
But you can check it since you WILL have a pencil thermometer.. right ?

sshanky · #**100** 06-23-2011, 10:28 PM

Yes, it will not cycle, and I will go get a proper pencil thermometer and not use my coffee thermometer

leathermang · #**101** 06-23-2011, 10:38 PM

Did you see the Northern Tools sample of the type of fan ?

1980sd · #**102** 06-24-2011, 12:58 AM

Auto Lo with the wheel at 65 will do it. This is a 116 with ACC?

sshanky · #**103** 06-24-2011, 01:14 AM

I have not seen that type of fan. Yes, it is a 116.120 (300SD) with ACC (servo type).

1980sd · #**104** 06-24-2011, 01:18 AM

That's right. Did you ever get your vacuum/servo issues worked out? I mad a lot of progress with mine and my compressor ***** the bed

sshanky · #**105** 06-24-2011, 12:20 PM

I did get the servo working pretty well using parts from another couple. of them. Not sure if it is perfectly calibrated, though. My most pressing but not so severe vacuum issue at this time is that when I shut off key the engine doesn't shut down immediately...it takes about 2 seconds to slowly shake to a stop -- IF the climate control is set to OFF. Otherwise, it shuts right down. I've adopted the habit of just pressing lo or hi before shutting off the key and everything seems to work fine. I would like to find out where the leak is, but I can't figure it out. I've tried blocking lines, changing the pushbuttons, and more...but no luck. If anyone needs advice on how to fix a servo, let me know...I got pretty good at it.