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Need some Guru advise-Low Idle/AC issue kinda....2004 Astro

3K views 27 replies 10 participants last post by  WimpTech 
#1 ·
Thanks for any help in advance.
I didn't know where to post this since I feel it's a multi problem issue, so I will start from a few weeks ago....
It was rainy here on Long Island for a few weeks,and the Astro was hesitating to start. Last time I had this problem, I changed the cap and rotor, and she started right up with no hesitation. The same thing started happening, so I changed the cap and rotor again(about a year old) and she started right up..... So first off, what would cause the cap and rotor to go bad after just about a year?????
It started getting hot here in NY, so I turned on my AC last week, and no air from the vents....No problem, I knew where to look, and found a vacuum hose off the 3 way thingy...LOL with a big fan made hole in it. Changed the hose, and air blowing like mad... Needless to say, the entire AC system was completely removed and replaced with OEM system, clutch, condenser, all plumbing etc...less than a year ago. But the AC was blowing warm. Last year when it was first done by the shop, it was like a freezer.... I brought it to the shop that replaced the system, and they wanted me to make an appointment, and leave it...No can do, since it's my work van, and I need it ...
Since fixing the vac hose, the Idle dropped, and she wants to stall. Running very low rpm, and always feels like it wants to stall at lights etc.
I disconnected the battery to reset the ECM thinking, maybe the computer was compensating for the Vac leak.
Still running rough, low idle, and no cold air...... :crying:
Can anyone be of any help trying to diagnose and fix these issues.
The poor old girl has 210K, and I am about 1 step away from selling her. But she has always been good to me.
Any help would be greatly appreciated.
Thanks
Steve
 
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#2 ·
water control valve. If it is stuck open then it is still getting hot water to the heater core. Turn it on vent but move the selector to cold side. If it is hot then the water valve is stuck.

Idle could be anything. Check spark, fuel pressure. Get a scanner and see what it is doing. If you have a EGR it could be stuck open a little blocked with carbon. Does the idle kick up when you turn the A/C on if not look at the IAC.
 
#3 ·
chevymaher said:
water control valve. If it is stuck open then it is still getting hot water to the heater core. Turn it on vent but move the selector to cold side. If it is hot then the water valve is stuck.

Idle could be anything. Check spark, fuel pressure. Get a scanner and see what it is doing. If you have a EGR it could be stuck open a little blocked with carbon. Does the idle kick up when you turn the A/C on if not look at the IAC.
The air is not hot, but it's not cold...LOL No clue where the water control valve is located on a 2004.
I hate having to take off the doghouse, but I will if I have to...LOL
Also, can't seem to find the IAC, which is possibly the issue.
Would a vacuum problem effect this.???
It was running perfectly fine until I fixed the vacuum leak. Maybe that 3 way valve went bad from dirt????
I only have access to a regular ODB, so the only code pulling up(yes, the SES light came on since the Vac line was fixed) is bad catalytic converter....But, it's less than a year old also...So I assume it's loading up due to the current issue.
Thanks
 
#5 ·
Water control valve is mounted to the passenger side front wheel well in the engine compartment, near the vacuum pot and looks kinda like a heart valve, 2 heater hoses going to it... no dog house removal required.

Try pull off what ever you put on the vacuum system and see if it runs right again; if so, then you've isolated the issue. There is a check valve in that vacuum line, might wanna check its working properly and facing the correct direction. Vacuum issues can cause it to run like crap and fire off a secondary o2 sensor fault, which could look like bad cat... exactly which code did it throw?

Yep, pretty sure it has an EGR, I don't trust the LAPS thing further than I can throw em.
I can't vouch for this video, but I'm pretty sure it applies to your van...


Good luck.
 
#9 ·
Depending on what you have to diagnose the A/C with, first things first....does the compressor clutch kick in and turn the compressor? IF yes, does it cycle on and off to the point of a few revolutions and then back off, then back on in a couple of seconds...that's a low coolant indicator. If it turns on and keeps running for an extended period of time, then feel the hoses. One will be really hot, so don't just grab onto them....the big silver canister should be cold, the fitting next to the radiator cap should be hot.

The heater valve is located directly below the silver canister. You should have a couple of heater hoses going to it as well as a vacuum line. It should be open by default. When A/C is commanded, the valve gets vacuum sent to it to close the valve. You should be able to watch the arm of the valve actuate as it is switched to A/C. ( If it's just you, switch to A/C, and while the engine is running, disconnect the bottom vacuum line coming out of the firewall..the valve should rotate back to the heat setting ( be default, no vacuum means you will have heat and defrost settings ). If all of that checks out, then you want to check the blend door operation. That is the door that is electronically actuated by a small electric encoder motor mounted under the dash ( it's triangular shaped ). This determines how much heat or cold is sent through the vents. You may have to take the doghouse off to see it move, but you can see the silver circle that protrudes from it with a slot cut in it up under the dash on the passenger side next to the doghouse with a flashlight. That one is easy to diagnose. With the car running, just command different levels of heat and you will see the slotted circle turn as it opens and closes the blend door. IF it doesn't move when you change the heat setting, then you need to address that first.
 
#10 ·
The clutch is not engaging. No change when the ac is turned on. The temperature definitely goes from hot to cold with the knob.
I am definitely low on coolant, so I'm going to fill it up now. The ac doesn't seem to turn on at all. Condenser does not get cold, and the clutch is not engaging. Since I am dead low on coolant, would that prevent the ac from turning on?
I sprayed carb cleaner on all the vac lines that I can see, with no change.
I am far from a mechanic, but I really want to try to find the cause. I am going to fill the coolant, and see.
Since the ac was done less than a Year ago, I have to assume it's either electrical or vacuum oriented. Is there a fuse or relay involved...? I can't believe that the ac was like an ice box last August, and now dead... LOL
 
#11 ·
Ok, nothing to do with the antifreeze. Only a little low.
Pulled the vac tube I fixed, and simply lost air blowing from the vents.
Pulled the relays and fuses marked "ac" and "hvac" nothing....
I can't access the small vac line going under the condenser without pulling the whole thing apart... LOL sprayed it while running, and no change.
I am determined.... But I am lost...
Could it be a relay?
 
#12 ·
Never assume anything is okay because it was working last year. Check to see if it has refrigerant. That is always the first check to do.

Reminds me of the woman who had a rod knock. I said have you checked the oil level. She said it was full when I bought it 3 years ago.
 
#15 ·
I will try that tomorrow.
My concern with that is that since the whole system is brand new, and was kicking serious butt last summer, why would it be empty???Possible leak? Under-filled after work done??? I have never seen any car loose Freon at such a rapid rate if this is the case.
Just doesn't make sense why it would loose a charge after less than a year...
And why the hell is my van having such a low idle/stalling suddenly? burning up a cap and rotor?
I know my alternator is on it's way out, but that would not have anything to do with what is going on.
I need to figure this out..LOL I will put it in the crusher if I can't
 
#16 ·
You have a leak somewhere... put in a can that has the green dye to find leaks... I have to charge mine every year... 12 oz cans are under $5 at my local Walmart...The caps suck on these... check for excessive play in the distributor gear...I had same rough idle and then no start...

I replaced the complete dizzy with a Skip White and my '03 AWD Astro with over 227,000 miles is running better than ever...
 
#17 ·
How does one check for excessive play in the distributor?
I am going to head to Walmart and get the freon(don't know which one... LOL)
My biggest problem is time to do all this. I need my van for work... The ac stinks, but I can sweat... I am more concerned with the low idle and stalling
 
#18 ·
Walmart sells only 1 kind of Freon, R-134a That is the only refrigerant you as a consumer can legally buy. They sell a few brands depending on store and location, but they generally have some for under $5 a can. Some brands are "Synthetic" What ever the hell that means. It is all synthetic since it is not a naturally occurring gas but is a chemical compound. Some is sold with Red dye or UV dye and some come with oils or sold as an "oil charge" Just buy the cheapest one if you have a set of gauges and a can tool else it will cost between $19-$30 for one large can (19 oz) that comes with a charging hose. Good luck on that. As far as the distributor goes, take off the cap grab the rotor and turn it from left to right. if it seems loose and can move a bit it may be worn. It should not move much.
 
#19 ·
Surfin Safari said:
Walmart sells only 1 kind of Freon, R-134a That is the only refrigerant you as a consumer can legally buy. They sell a few brands depending on store and location, but they generally have some for under $5 a can. Some brands are "Synthetic" What ever the hell that means. It is all synthetic since it is not a naturally occurring gas but is a chemical compound. Some is sold with Red dye or UV dye and some come with oils or sold as an "oil charge" Just buy the cheapest one if you have a set of gauges and a can tool else it will cost between $19-$30 for one large can (19 oz) that comes with a charging hose. Good luck on that. As far as the distributor goes, take off the cap grab the rotor and turn it from left to right. if it seems loose and can move a bit it may be worn. It should not move much.
Thank you.
I will pull the evil doghouse tomorrow...LOL check for play. What would be considered "normal"....L/R 1/4 inch, more? Less?
Sorry for the ignorance, but I never had to check one. I will have to post a video when I do it.
As far as refrigerant, I live on Long Island, I can probably acquire plutonium if required...LOL
Is there a "Best" to use? I will get the cheap wally world stuff to start since I probably have a leak. But if I find the leak, I want to fill it with the good stuff... ;)
 
#23 ·
As far as the low idle is concerned, I'd look at cleaning the MAF as the wires get dirty and cannot properly read the incoming air charge. The two wires should be silver and shiny. If not, hose them down with CRC MAF cleaner, let it dry completely and test it out. The coolant sensor could also be a culprit but you'll need a scanner to read data to see if its messed up.
 
#24 ·
redfury said:
As far as the low idle is concerned, I'd look at cleaning the MAF as the wires get dirty and cannot properly read the incoming air charge. The two wires should be silver and shiny. If not, hose them down with CRC MAF cleaner, let it dry completely and test it out. The coolant sensor could also be a culprit but you'll need a scanner to read data to see if its messed up.
I personally have never had any luck just cleaning the MAF, it has never changed anything in the performance of my van's when I've been having a MAF issue... I've always had to replace it with a new one to see any difference in performance.
 
#25 ·
Me either, but it never hurts to give it a shot. If it's truly dirty, then it should help. Of course, the only way to really determine if the MAF is bad is to use an automotive oscilloscope...though there is a multi meter test as well.

Bad idling due to the input to the computer though is going to be either the signal from the MAF, MAP , coolant sensor or Knock Sensors. Otherwise I'd suspect knife edging of the distributor gear, or possibly a problem with the fuel pressure regulator. If there is a need for extended cranking to start the motor, a failing pressure regulator could be the culprit.
 
#26 ·
You don't put R-12 into a system that takes R-134a.

Ever.

R-414b will work great in both R-12a system and R-134a systems, but that's about it.

Tell your friend to sell those cans - they're worth about $40-$50 per pound...and then buy R-134a without sealant in it. Just straight R-134a.

(my husband is an HVAC-R master)
 
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