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Econoline with cummins. Everything new & by the book, compressor cuts out on low pressure.


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rebar
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Jul 19, 2015, 10:04 AM

Post #1 of 22 (1977 views)
Econoline with cummins. Everything new & by the book, compressor cuts out on low pressure. Sign In

1995
Ford
Econoline E350 van
5.9 cummins 5 speed
280000 miles

I'm starting a new thread after doing exactly what I was told to do on my last topic.

I replaced the compressor, condenser, accumulator and O-tube and drained all oil after removing the evap, as well as all O rings treated with nylog. Started with the factory 5 oz of oil in the compressor after spinning it by hand 15 times, and 2 oz in the accumulator inlet. Pulled vacuum, triple evac, to 250 microns. Added the factory 2.75 lbs/44 oz of 134a as a liquid before even starting the engine.

I started the engine in the driveway and turned ac to Max, and saw 33 low and 185 high, 52 degree vent air at 80 degree ambient at 900 rpm idle. Those pressures seemed a little low, but I was scolded for adding more than the factory 44 oz last go around with original compressor before the clutch smoked.

So I took the van for a drive down the interstate since my condenser isn't in a shroud connected to the radiator. The condenser does have foam strips sealing the outside edges to the radiator, but has a 3/4" gap on the top and bottom where air could leak past.
At 65 mph I turned the AC to max and was disappointed with the 60 degree air coming from the vents. I have more air flow now that I replaced the blower motor, so it was slowly cooling the interior to a tolerable temperature after 5 minutes. But I hoped for cooler vent temperatures after spending all this money and time.

Today I put a huge fan in front of the van, and set my idle to 1700 rpm to recheck pressures. I had 25 low and 175 high at 80 degree ambient with 52 degree vent air and dropping. Slowly, the low side kept going lower, and I saw 23 psi right before the compressor was turned off by the low pressure switch, I assume.

So what's my issue now?
Doesn't the compressor only get cut off by the low pressure switch if the system is low on refrigerant?? My only explanation is my hoses might be longer since the van has been re-powered, but I really have no idea, and am tempted to add refrigerant to at least keep the low side pressure above 25 and the compressor running.

Thanks!




Hammer Time
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Jul 19, 2015, 10:33 AM

Post #2 of 22 (1971 views)
Re: Econoline with cummins. Everything new & by the book, compressor cuts out on low pressure. Sign In

Your pressures and refrigerant system sound fine. Have you tried pinching off one of the heater hoses to make sure you don' thave heat bleeding in.



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rebar
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Jul 19, 2015, 10:39 AM

Post #3 of 22 (1969 views)
Re: Econoline with cummins. Everything new & by the book, compressor cuts out on low pressure. Sign In


In Reply To
Your pressures and refrigerant system sound fine. Have you tried pinching off one of the heater hoses to make sure you don' thave heat bleeding in.


Thanks.. I didn't think running below 22 psi with the compressor cutting in and out was normal operation.

The heater core hoses have been completely disconnected.

If there was a good way to remove refrigerant by weight, I would be adding.


(This post was edited by rebar on Jul 19, 2015, 10:42 AM)


Hammer Time
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Jul 19, 2015, 10:42 AM

Post #4 of 22 (1966 views)
Re: Econoline with cummins. Everything new & by the book, compressor cuts out on low pressure. Sign In

Oh yes, that would be normal. That's why it is called a "cycling system". It prevents evaporator freeze up.



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Tom Greenleaf
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Jul 19, 2015, 11:13 AM

Post #5 of 22 (1960 views)
Re: Econoline with cummins. Everything new & by the book, compressor cuts out on low pressure. Sign In

Just how did you get entire charge into this without running the engine? You can but do you have that type equipment? So where did it go?
Need to fix those leaks around condenser - way too much air to bypass it IMO.


Pressures OK for now but are never an entire story. At raised idle H. should be about 2.2 to 2.5 X temp going right into grille not the day's temp.


Vent temp was disappointing on highway to me. Use center vent, recirc. Van body especially make sure the air dam isn't missing or air doesn't flow well thru grille the faster you go.


Wet it down and watch pressure - water beats air every time.


Did you say it waits till 23 PSI to cycle off? That's a tad low or should be able to ice evap around there. Does condensate quit dripping? Proof of that then when cuts off pours out water.


In short and again, how did whole charge go into a vacuum without compressor engaged?
Fix leaks around condenser.


After that make sure your measurements are correct and wonder if how much is in it is a total unknown right now?


T



Hammer Time
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Jul 19, 2015, 11:50 AM

Post #6 of 22 (1955 views)
Re: Econoline with cummins. Everything new & by the book, compressor cuts out on low pressure. Sign In

22 to 24PSI is completely normal for low pressure cycle off. Most GMs and Ford use approx 22off and 48on which gives them an average of 30-36. Some Chryslers pull all the way down to 18. A lot depends on the placement of the switch too.



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Tom Greenleaf
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Jul 19, 2015, 12:00 PM

Post #7 of 22 (1951 views)
Re: Econoline with cummins. Everything new & by the book, compressor cuts out on low pressure. Sign In

Ya - not the problem at all if there really is one? It cycles and would melt instantly unless there for quite a while. I'm not thrilled with the performance but not so sure temp observations are correct yet.


IMO and experience is the higher capacity CCOT systems like this are NOT as fussy about a couple ounces off on exact charge.


Lots to cool with this vehicle. If hot in sun while working takes some time to really work well but the highway run to me suggests too much air isn't getting thru condenser but around it?


T



Hammer Time
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Jul 19, 2015, 12:03 PM

Post #8 of 22 (1948 views)
Re: Econoline with cummins. Everything new & by the book, compressor cuts out on low pressure. Sign In

[quote\I started the engine in the driveway and turned ac to Max, and saw 33 low and 185 high, 52 degree vent air at 80 degree ambient at 900 rpm idle


There's nothing wrong with that condenser. I'd like to see what te pressures do going down the highway but it sounds like heat is getting mixed in.



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rebar
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Jul 19, 2015, 12:27 PM

Post #9 of 22 (1946 views)
Re: Econoline with cummins. Everything new & by the book, compressor cuts out on low pressure. Sign In


In Reply To
Just how did you get entire charge into this without running the engine? You can but do you have that type equipment? So where did it go?
Need to fix those leaks around condenser - way too much air to bypass it IMO.

T


I don't know. I used a accurate scale and 30 lb 134a tank upside down until I saw 2.75 lbs missing. I was relieved, because the weight can change when you flip the tank right side up for gas. In fact, after I flipped it over without adding more, the scale said I had only added 2.55 lbs but I figured it was the way the gauge lines were laying.


In Reply To
Pressures OK for now but are never an entire story. At raised idle H. should be about 2.2 to 2.5 X temp going right into grille not the day's temp.

T


So 80 X 2.5 = 200 so Im a bit lower.


In Reply To
Vent temp was disappointing on highway to me. Use center vent, recirc. Van body especially make sure the air dam isn't missing or air doesn't flow well thru grille the faster you go.

T


Air dam? Not sure what that is, but all the parts on the front end are on, condensor mounted via factory mounts.. I replaced the grill with a aftermarket grill which has more free area.


In Reply To
Wet it down and watch pressure - water beats air every time.
T


OK, will try that. But I don't understand what that would tell me.


In Reply To
Did you say it waits till 23 PSI to cycle off? That's a tad low or should be able to ice evap around there. Does condensate quit dripping? Proof of that then when cuts off pours out water.

T


Yes, Around 23 psi is where compressor cut out. I didn't watch the condensate, but will next time I test.


In Reply To
Fix leaks around condenser.

After that make sure your measurements are correct and wonder if how much is in it is a total unknown right now?
T


I'm not seeing how I can fix those leaks as there is nowhere to attach a shroud easily as the top and bottom edges of the radiator and condenser don't match. The condenser is about 4" shorter, but centered.

No, not unknown.. I'm sure the Inficon Way-TEK digital refrigerant scale I used said 2.75 lbs before I shut it off and flipped up right side up. But then it did say 2.55 lbs because of the gauge line positions I think..


In Reply To
IMO and experience is the higher capacity CCOT systems like this are NOT as fussy about a couple ounces off on exact charge.

If hot in sun while working takes some time to really work well but the highway run to me suggests too much air isn't getting thru condenser but around it?
T


I figured 65 mph was enough air flow even without a fan..


In Reply To
There's nothing wrong with that condenser. I'd like to see what te pressures do going down the highway but it sounds like heat is getting mixed in.


New condenser..

I was tempted to take the dog house off and run the gauge lines so I can read them while driving. That would be hot and loud, but I will do it if you think I should..

Ill take your word on the compressor cycling.. But it just sounds like unneeded wear and tear on the clutch. And inconsistent performance..


I appreciate all the advice here.
Thanks


(This post was edited by rebar on Jul 19, 2015, 12:33 PM)


Tom Greenleaf
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Jul 19, 2015, 1:42 PM

Post #10 of 22 (1936 views)
Re: Econoline with cummins. Everything new & by the book, compressor cuts out on low pressure. Sign In

Do you have another thermometer just to see?


* Not ready to complain about pressures as there are things still at large, it's cooling at all and pressure is being made - so that's all good.


* Whole charge into vac thing? Yes it's possible to get real dang close if cans are hot or heated. Quite simple, higher pressure goes to the lower - that's no magic. Just a bit unusual to me at least.


* Air Dam: That's usually a plastic under bumper spoiler thing that usually breaks off. Air at speed creates a vacuum on the under side of engine such that air thru grille will have a place to go. If more pressure of air speed is jamming under bumper you end up with a stall of air flow or less even with fans. You are totally correct the a big square grille at speed usually even 35MPH or so is enough air so you don't need fans at all. Those issues are rarish and you might put gauges on and in sight on high side tied wipers or something with a complaint like that -- OR like I said hose down condenser with a reasonable mist of water of course only while still then and that's the most heat transfer you'll get out of a condenser. Low would drop off as well and compressor cycle on a real hot day doing that.
Other considerations are this is a HD thing. Probably has trans cooler, maybe engine oil, PS fluid and maybe more up front of all this ahead of condenser but if condenser isn't cooling pressure of it being hot should be higher then?
The other rare (but listed as something) is radiant heat backward from a hot radiator - then again pressures would be higher on high side.


Just sitting there you should be able to feel inlet and outlet to evaporator and should be about the same temp. Accumulator should be cool to cold and or even sweating unless wildly dry dew points/humidity.


Didn't you say you had evaporator out too? If so is it really snug in place and no air getting around it? That would throw it off too.


Just some things to check out before what I call "tweaking" a system. Have to know all things are working properly and thermo everywhere to pick the right charge if it isn't known exactly and plenty of those come my way - altered or retrofits from R-12 can be a pest to get spot on.


Too much isn't good and to be avoided and or if air got in somehow all bets change for performance.


To a vacuum I add thru high side with vac gauge on low side all in vacuum till low is just slight positive pressure then continue with low only, liquid, engine off till equalized with source pressure. I'm near certain I have as close to zero air mixed in which is always going to confuse pressures and performance.


Making quite a book out of this. You've done a lot to get this right and maybe just take a break and check it again later making sure caps don't leak as well and think Ford only uses a large Schrader valve at the ports. Ball valves stink and can leak if just touched!


Give it a rest for now and check again later. Now that it has a charge also look for leaks not seen in holding a vacuum - it's possible and better to know now while this is so close to finished up,


T



Hammer Time
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Jul 19, 2015, 2:11 PM

Post #11 of 22 (1931 views)
Re: Econoline with cummins. Everything new & by the book, compressor cuts out on low pressure. Sign In

Like I said 4 posts ago, pinch off a heater hose and try it again. This has all the symptoms of a blend door problem.



Quote
Ill take your word on the compressor cycling.. But it just sounds like unneeded wear and tear on the clutch. And inconsistent performance..


This is exactly how the system is designed to work. That's why it is called a CCOT system (Cycling Clutch Orifice Tube}

http://www.freeasestudyguides.com/ac-cycling-clutch-orifice-tube.html




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rebar
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Jul 19, 2015, 4:51 PM

Post #12 of 22 (1922 views)
Re: Econoline with cummins. Everything new & by the book, compressor cuts out on low pressure. Sign In

Yes I'm giving it a rest for a while.

My thermometers are accurate.


I believe the 30 lb tank I used helped get the entire charge in with its uninterrupted liquid supply . I put the entire charge in the lowside.


From the look of some E350 pictures, I am missing the air damn.. Thanks for pointing that out. The later years had bumper vents as well, which might help.
I'm not that concerned since my condenser pressures seem ok. But more air flow is always welcome so I will check if I can find a used one monday.

I'm still trying to come up with a way to shroud the condenser to the radiator.

Rusty Radiator on top. Condenser right below. And if you look close, the intercooler..


The evap was loose and I used some armaflex foam tape to seal it. But I'm sure it leaks around it a little.

Hammer.. No need to pinch off the heater hose. Those hoses were the first thing I disconnected. The heater core is capped off and hoses coupled together.

And thanks for the link to how a CCOT system works. But it does say.. "This is why this system keeps cycling the compressor when the system is low "

I just cant wrap my head around a design that cycles the compressor in normal conditions. Sure, when its cool out. But during summer heat, it should run flat out IMO, just like my home a/c I sized and installed. I rarely rely on the t-stat to cycle it to get as much humidity out of the home, and the fact cycling drives me nuts. It drops the temp 1 degree per hour most days with humidity around 40%.

It must just be me, and the idea that if the van system ran with a lowside pressure a little above the cut out pressure. It would remove more btu's, without the short interruptions, and have less wear and tear on the clutch. Unless of course , the high side was so high, the compressor was stressed out pumping it. And nowhere for excess refrigerant to reside with no receiver.






Hammer Time
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Jul 19, 2015, 4:58 PM

Post #13 of 22 (1920 views)
Re: Econoline with cummins. Everything new & by the book, compressor cuts out on low pressure. Sign In

It has to operate that way or the evaporator will freeze up. The low side pressure pretty much correlates to the core evaporator temp so it cannot continue at 20 PSI or it will freeze up. Systems that use an expansion valve have a thermostat probe in the evaporator to prevent freezing. This system is designed to turn on and off to control evap temps. I would guess that you have the blower turned down when it is doing this. If the blower is on high, it lighely won't do much cycling. Lowering the blower speed lowers the pressure.



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rebar
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Jul 19, 2015, 5:17 PM

Post #14 of 22 (1914 views)
Re: Econoline with cummins. Everything new & by the book, compressor cuts out on low pressure. Sign In


In Reply To
It has to operate that way or the evaporator will freeze up. The low side pressure pretty much correlates to the core evaporator temp so it cannot continue at 20 PSI or it will freeze up. Systems that use an expansion valve have a thermostat probe in the evaporator to prevent freezing. This system is designed to turn on and off to control evap temps. I would guess that you have the blower turned down when it is doing this. If the blower is on high, it lighely won't do much cycling. Lowering the blower speed lowers the pressure.


OK understood.
But if you added a few oz's and raised the pressure in the lowside a little to 29 psi @ 34 degree's at 2000 rpm, there's no worry of freeze up.

Most things I read on the net says a cycling compressor means low charge or a clogged orifice tube. And I know its not the o tube.
But you guys are the experts and I enjoy learning.


(This post was edited by rebar on Jul 19, 2015, 5:18 PM)


Hammer Time
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Jul 19, 2015, 5:22 PM

Post #15 of 22 (1911 views)
Re: Econoline with cummins. Everything new & by the book, compressor cuts out on low pressure. Sign In

OK, I can only explain this so many times. The pressure is going to change with temperature so on real hot day on high fan the pressure will be much higher and you won't have cold air so you can't pump it up with refrigerant. You will just lose cooling capacity. The system is designed to cycle under certain conditions, period, assuming you have the correct charge to start with.



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Discretesignals
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Jul 19, 2015, 6:09 PM

Post #16 of 22 (1908 views)
Re: Econoline with cummins. Everything new & by the book, compressor cuts out on low pressure. Sign In

Looking at some of the refrigerant hoses. Where the hoses altered? Possibly the different hoses than what was originally stock has changed the system capacity? If you have the blower running high and vent temps 50-60, it shouldn't be cycling.





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.

(This post was edited by Discretesignals on Jul 19, 2015, 6:14 PM)


rebar
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Jul 19, 2015, 7:13 PM

Post #17 of 22 (1902 views)
Re: Econoline with cummins. Everything new & by the book, compressor cuts out on low pressure. Sign In


In Reply To
Looking at some of the refrigerant hoses. Where the hoses altered? Possibly the different hoses than what was originally stock has changed the system capacity? If you have the blower running high and vent temps 50-60, it shouldn't be cycling.


I don't believe so.

It was 52 vent in the driveway because it was 33 psi and not cycling. As soon as I drove, or increased rpm the pressure dropped and cycled the compressor giving me the 60 degree vent air.


Tom Greenleaf
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Jul 19, 2015, 11:49 PM

Post #18 of 22 (1892 views)
Re: Econoline with cummins. Everything new & by the book, compressor cuts out on low pressure. Sign In

Late and just catching up some with this - sorry.


Some good info and thoughts for you. Chart: If you know temps you know pressure and vs versa - exactly!


Get rid of those thermometers! They are messing you up. Get infrared touchless instant ones. Key fob size from $10-$25, pistol type with laser in front of me was just $25! Most tons more this one new to me but accurate. Just now - in my kitchen, computer screen is 86F, ceiling is 77.5F. Ice in freezer is -12.5F - EXACTLY! No games, no mistakes instant results. Use the glass ones with lube for you know whereMad
OK on total fill with 30lb tank. If that was full and warm it would be close into a vacuum.


Have to have good info or you are spinning your wheels. Evap leaks a little mean VOLUMES! That alone is probably most of the whole issue! It can't leak at all and you've ruled out heater core influence but not necessarily ambient air getting around a blend door.


Routing of hoses at question by DS. Valid still. See exactly where they pass by what and check temp along them. OE, '78 Vette put return hose so close to an exhaust manifold (factory) couldn't make the sucker blow below 55F and wasn't even hot out that day. No room for moving it - original design was flawed as were cooling systems on most of them. All that for that was fine and not the intention of the car. Not the case but you are trying to cool a huge area to cool with similar designs as that. It all matters.
Until you test with water on condenser, fix leaks around condenser and evap plus know temps in one second observations are invalid IMO.


You couldn't tweak this system without better info from your equipment.


Air dam continued: Fix that! This van style is blasting air I thru grille and pushing heat forward. Feel it! It has so little room to escape it too is engine area heat invading past evaporator not just ambient air.


You sound very interested in this game if you will and it is but reality. It's a total study of properties of what in what conditions at the moment not even an hour later it's all new again.
I dare say no shop is going to spend the day screwing with this for you for love nor money to gain few degrees output temps but you can if you wish.


May want to start charge over from a vacuum again - give the refrigerant away and use known pure again. If you toss one little mess like air contamination into this nothing is going to behave even wrong consistently and cause total hair loss! It's getting late or is it early?


Takes time, tools and lots of know how and you know the areas now of concern.


Sorry - lots to read here. You showed rust underside. That's nothing IMO unless there's unseen debris somehow piling up blocking air flow............


Tom

(This post was edited by Tom Greenleaf on Jul 19, 2015, 11:56 PM)


rebar
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Jul 22, 2015, 5:46 AM

Post #19 of 22 (1849 views)
Re: Econoline with cummins. Everything new & by the book, compressor cuts out on low pressure. Sign In


In Reply To
Get rid of those thermometers! They are messing you up. Get infrared touchless instant ones. Key fob size from $10-$25, pistol type with laser in front of me was just $25! Most tons more this one new to me but accurate. Just now - in my kitchen, computer screen is 86F, ceiling is 77.5F. Ice in freezer is -12.5F - EXACTLY! No games, no mistakes instant results. Use the glass ones with lube for you know whereMad
OK on total fill with 30lb tank. If that was full and warm it would be close into a vacuum.


Have to have good info or you are spinning your wheels. Evap leaks a little mean VOLUMES! That alone is probably most of the whole issue! It can't leak at all and you've ruled out heater core influence but not necessarily ambient air getting around a blend door.


Routing of hoses at question by DS. Valid still. See exactly where they pass by what and check temp along them. OE, '78 Vette put return hose so close to an exhaust manifold (factory) couldn't make the sucker blow below 55F and wasn't even hot out that day. No room for moving it - original design was flawed as were cooling systems on most of them. All that for that was fine and not the intention of the car. Not the case but you are trying to cool a huge area to cool with similar designs as that. It all matters.
Until you test with water on condenser, fix leaks around condenser and evap plus know temps in one second observations are invalid IMO.


You couldn't tweak this system without better info from your equipment.


Air dam continued: Fix that! This van style is blasting air I thru grille and pushing heat forward. Feel it! It has so little room to escape it too is engine area heat invading past evaporator not just ambient air.


You sound very interested in this game if you will and it is but reality. It's a total study of properties of what in what conditions at the moment not even an hour later it's all new again.
I dare say no shop is going to spend the day screwing with this for you for love nor money to gain few degrees output temps but you can if you wish.


May want to start charge over from a vacuum again - give the refrigerant away and use known pure again. If you toss one little mess like air contamination into this nothing is going to behave even wrong consistently and cause total hair loss! It's getting late or is it early?


Takes time, tools and lots of know how and you know the areas now of concern.


Sorry - lots to read here. You showed rust underside. That's nothing IMO unless there's unseen debris somehow piling up blocking air flow............


Tom


Thanks Tom, I really appreciate the input and no need to apologize. Because this project has become one of the most rewarding for me as of last night.

Oh and hey, woe woe woe. Get off my old school glass thermometers. I trust them.

As far as my evap leaking by. Evap was really loose before I foam taped it. But I'm talking about the bottom which has no foam so it can drip off and drain well. Its got to leak past. Nothings perfect.

Ambient air getting around a blend door.. How do I test that?

Hose routing is another good question. I know the discharge hose came in contact with the turbo compressor discharge pipe, so I zip tied protection over it but wasn't concerned since it was highside. Its not exhaust. But I imagine its pretty toasty in the general turbo area. Last pull up monarch pass some insulation fell and I had a fire right there. More like smoldering thank god.

The water might not happen. But I did turn the big fan off for a minute and watched condenser pressure rise 10 psi to 190 at 1900 rpm.

Air contamination isn't even in question for me. And if you had watched me pull vacuum you'd agree.

So back to last night..

I added 2 oz and that made a big difference. I'm more satisfied now.

78 ambient. My pressures remained at 28/160 at 750 rpm with no cycling.

At 1900 rpm ,65 mph, the compressor started cycling again. But this time the cycling slowed, and the lowside pressure stayed lower (high of 42) during the off cycles. On cycles were longer. Vent air dropped to 48 ! From 60. Evap wasnt flooded.

So adding two oz's dropped vent air 12 degrees.

With a highside that never went over 180, I think there might still be room for lower vent temps and less cycling.

Id like it to run 2000 rpm at 29 and hold, no cycling, like it does now at 750. But also considering leaving it alone with 48 degree vent air.

I downloaded the video of how the system cycles at higher rpm after adding the 2 oz. First at idle 28/160 without cycling, and then cycling at cruising rpms. 26/175

Should I leave well enough alone? Or is there a chance I can get lower than 48 vent? Did I mention I hate cycling?
Whats worse? Engaging the clutch constantly, or running a little higher head pressure? The accumulator will catch any liquid if it actually makes it there.


http://vid640.photobucket.com/...5A9B_zpsmx40zuza.mp4


(This post was edited by rebar on Jul 22, 2015, 5:49 AM)


Tom Greenleaf
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Jul 22, 2015, 6:15 AM

Post #20 of 22 (1844 views)
Re: Econoline with cummins. Everything new & by the book, compressor cuts out on low pressure. Sign In

Get a dang real thermometer! Glass is still fine but too slow and can't target objects with instant results. Now you said high side does get near something hot. Just great. So it has liquid under pressure in that line ready to go thru "O" tube to expand and might part expand right there from heat and not all the time. Right thermo would see that.


Adding more refrigerant just covered that up so at all. NO - DON'T FORCE IT TO COMPRESS MORE. IF YOU DO GET AN OVERLOAD OF LIQUID REFRIGERANT RETURNED TO COMPRESSOR IT WOULD LOCK UP AS YOU CAN'T COMPRESS A LIQUID. That's why they cycle in part.


Hey and BTW - you are doing real well at paying attention as I see it. Many/all of us have been frustrated with some contraption at some point and trying (speak for myself) to alert you to area that get you in trouble. Most folks who come here we strongly suggest they don't touch A/C stuff for their own good!


So adding 2 oz made a huge difference. It could either stay that way if happy or see if liquid line is evaporating early because of heat and now can't because of change of charge? You decide. If mine I'd want to know. Not certain but seem you've "tweaked" it for the conditions it's exposed to now off any known charts. That's fine when things stay constant.


Sorry for lengthy posts both habit but don't want to miss something important.


So far I trust your efforts, understanding way above the average hit n run A/C crap we hear about. Keep up careful work or changes.


None of this is for everyone. Most would be so frustrated so fast or blow the system up with poor ideas of why something isn't perfect instantly would have totally failed long ago.


Give you credit for your staying power for this!


Tom


rebar
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Jul 22, 2015, 7:44 AM

Post #21 of 22 (1839 views)
Re: Econoline with cummins. Everything new & by the book, compressor cuts out on low pressure. Sign In

Thanks again. OK, I wont add anymore.

The a/c compressor discharge line touching the post turbo intake pipe (the pipe connecting the turbo to the intercooler) doesn't get hot at idle or at little boost. Maybe 100 degrees. Its when I'm driving, towing, it will get hotter. But the pipe is connected with radiator hose so it must stay under 200. I would need to have a probe on the pipe to know how hot it gets when hammering down. I should probably completely insulate my exhaust manifold, turbo, and downpipe.

Whats the best material or stand off to place between the a/c discharge line and pre intercooler pipe?


(This post was edited by rebar on Jul 22, 2015, 7:48 AM)


Tom Greenleaf
Ultimate Carjunky / Moderator
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Jul 22, 2015, 8:14 AM

Post #22 of 22 (1832 views)
Re: Econoline with cummins. Everything new & by the book, compressor cuts out on low pressure. Sign In

? Up to 200F or area isn't the concern to me. Exhaust temps spike up to glowing hot which is about 650F or so? Not totally sure as I still refuse to ride under a hood with a thermo while a vehicle is under wild load at high RPM to checkCool


General under the hood temps are all up there while running and within norms expected for A/C. You probably don't have to do anything. If you found this performing erratically and that was in question I think I'd check out HVAC products for non automotive use for a selection. IDK - see folks insulate wood stoves from walls and stuff that must be fireproof and not make a melted mess either.


There are some problems with insulating things too like accumulators and return lines that come with foam insulation. They stay wet, sometimes with salt too from the roads in Winter that you can't see and they rust out those parts. Suggestion when noticed is remove it on some put there by factory! That would only be if it was a problem and found rusted out parts when system quit all at once and that was it.


Perhaps for now best to leave well enough alone and drive the thing. Monitor output temps under what conditions will normally impair cooling, stop and go traffic over hot pavement on hot day, heavy loads in tow and so on don't expect it to be identical each day but rather "credible." Nice if you can catch a problem real early before it can cause some failure that makes you do this all over again.


I'm sure it's hard to hear while driving but notice any unusual noises also.


You just might be done but no harm in double checks before forgetting this for hopefully a good long time,


T







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