A Cars forum. AutoBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » AutoBanter forum » Auto newsgroups » Technology
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

Why would AC only work when foot is on gas?



 
 
Thread Tools Display Modes
  #1  
Old August 22nd 06, 07:46 PM posted to rec.autos.tech
David
external usenet poster
 
Posts: 2
Default Why would AC only work when foot is on gas?

Our family has two Isuzu Rodeos, a 1995 and a 1997. The AC on the 1995
works great. the 1997 stinks. On the '97 Rodeo when I'm sitting still,
it gets very hot when the car is idling. My first thought is that the
engine is getting so hot, I need to be moving to have the additional
air cooling. However, I discovered today, the AC work fine when I'm
sitting at a stop light if I just put the vehicle in neutral and give
it gas. Strangely enough though, the 1995 doesn't do that. Sitting
idle in the sun it cools so well that after 5-10 minutes you have turn
down the AC.

Any ideas why the '97 is having this problem? Is it an AC problem, AC
clutch? harmonic balancer, or just a design flaw? Works great on the
freeway, but in city traffic in Dallas I'm quickly getting up to 100+.

many thanks for any suggestions!
David

Ads
  #2  
Old August 22nd 06, 08:00 PM posted to rec.autos.tech
[email protected]
external usenet poster
 
Posts: 5
Default Why would AC only work when foot is on gas?

maybe you have a power problem bring it in to autozone and they can
test for free!
David wrote:
> Our family has two Isuzu Rodeos, a 1995 and a 1997. The AC on the 1995
> works great. the 1997 stinks. On the '97 Rodeo when I'm sitting still,
> it gets very hot when the car is idling. My first thought is that the
> engine is getting so hot, I need to be moving to have the additional
> air cooling. However, I discovered today, the AC work fine when I'm
> sitting at a stop light if I just put the vehicle in neutral and give
> it gas. Strangely enough though, the 1995 doesn't do that. Sitting
> idle in the sun it cools so well that after 5-10 minutes you have turn
> down the AC.
>
> Any ideas why the '97 is having this problem? Is it an AC problem, AC
> clutch? harmonic balancer, or just a design flaw? Works great on the
> freeway, but in city traffic in Dallas I'm quickly getting up to 100+.
>
> many thanks for any suggestions!
> David


  #3  
Old August 22nd 06, 08:47 PM posted to rec.autos.tech
John S.
external usenet poster
 
Posts: 981
Default Why would AC only work when foot is on gas?


David wrote:
> Our family has two Isuzu Rodeos, a 1995 and a 1997. The AC on the 1995
> works great. the 1997 stinks. On the '97 Rodeo when I'm sitting still,
> it gets very hot when the car is idling. My first thought is that the
> engine is getting so hot, I need to be moving to have the additional
> air cooling. However, I discovered today, the AC work fine when I'm
> sitting at a stop light if I just put the vehicle in neutral and give
> it gas.



I want to be sure I understand what is happening here. At an idle is
the compressor turning?

If the compressor is turning at idle it sounds like the AC system needs
a recharge.



> Strangely enough though, the 1995 doesn't do that. Sitting
> idle in the sun it cools so well that after 5-10 minutes you have turn
> down the AC.
>
> Any ideas why the '97 is having this problem? Is it an AC problem, AC
> clutch? harmonic balancer, or just a design flaw? Works great on the
> freeway, but in city traffic in Dallas I'm quickly getting up to 100+.
>
> many thanks for any suggestions!
> David


  #4  
Old August 23rd 06, 02:56 AM posted to rec.autos.tech
Don[_1_]
external usenet poster
 
Posts: 300
Default Why would AC only work when foot is on gas?

On 22 Aug 2006 11:46:29 -0700, "David" >
wrote:

>Our family has two Isuzu Rodeos, a 1995 and a 1997. The AC on the 1995
>works great. the 1997 stinks. On the '97 Rodeo when I'm sitting still,
>it gets very hot when the car is idling. My first thought is that the
>engine is getting so hot, I need to be moving to have the additional
>air cooling. However, I discovered today, the AC work fine when I'm
>sitting at a stop light if I just put the vehicle in neutral and give
>it gas. Strangely enough though, the 1995 doesn't do that. Sitting
>idle in the sun it cools so well that after 5-10 minutes you have turn
>down the AC.
>
>Any ideas why the '97 is having this problem? Is it an AC problem, AC
>clutch? harmonic balancer, or just a design flaw? Works great on the
>freeway, but in city traffic in Dallas I'm quickly getting up to 100+.
>
>many thanks for any suggestions!
>David


A weak compressor will work half-assed at high rpm and cool little or
not at all at low rpm. This can easily be verified with gauges. You
might see 70-80 PSI low side, maybe 130 high side at idle. Should be
more like 30/200 but this is dependent on MANY factors.

Don
www.donsautomotive.com

  #5  
Old August 23rd 06, 02:57 AM posted to rec.autos.tech
Don[_1_]
external usenet poster
 
Posts: 300
Default Why would AC only work when foot is on gas?

On 22 Aug 2006 12:47:35 -0700, "John S." > wrote:

>
>David wrote:
>> Our family has two Isuzu Rodeos, a 1995 and a 1997. The AC on the 1995
>> works great. the 1997 stinks. On the '97 Rodeo when I'm sitting still,
>> it gets very hot when the car is idling. My first thought is that the
>> engine is getting so hot, I need to be moving to have the additional
>> air cooling. However, I discovered today, the AC work fine when I'm
>> sitting at a stop light if I just put the vehicle in neutral and give
>> it gas.

>
>
>I want to be sure I understand what is happening here. At an idle is
>the compressor turning?
>
>If the compressor is turning at idle it sounds like the AC system needs
>a recharge.


If so it would cycle off when reved up.

Don
www.donsautomotive.com
>
>
>
>> Strangely enough though, the 1995 doesn't do that. Sitting
>> idle in the sun it cools so well that after 5-10 minutes you have turn
>> down the AC.
>>
>> Any ideas why the '97 is having this problem? Is it an AC problem, AC
>> clutch? harmonic balancer, or just a design flaw? Works great on the
>> freeway, but in city traffic in Dallas I'm quickly getting up to 100+.
>>
>> many thanks for any suggestions!
>> David


  #6  
Old August 23rd 06, 02:51 PM posted to rec.autos.tech
Steve[_1_]
external usenet poster
 
Posts: 3,043
Default Why would AC only work when foot is on gas?

David wrote:

> Our family has two Isuzu Rodeos, a 1995 and a 1997. The AC on the 1995
> works great. the 1997 stinks. On the '97 Rodeo when I'm sitting still,
> it gets very hot when the car is idling. My first thought is that the
> engine is getting so hot, I need to be moving to have the additional
> air cooling. However, I discovered today, the AC work fine when I'm
> sitting at a stop light if I just put the vehicle in neutral and give
> it gas. Strangely enough though, the 1995 doesn't do that. Sitting
> idle in the sun it cools so well that after 5-10 minutes you have turn
> down the AC.
>
> Any ideas why the '97 is having this problem? Is it an AC problem, AC
> clutch? harmonic balancer, or just a design flaw? Works great on the
> freeway, but in city traffic in Dallas I'm quickly getting up to 100+.
>
> many thanks for any suggestions!
> David
>


Usually poor cooling at idle that is solved by revving up the engine is
either too little air-flow over the condensor due to a weak
engine-driven fan, a compressor that has a dead cylinder or two (usually
due to broken reed valves) and is down on capacity, or low refrigerant
charge.

  #7  
Old August 23rd 06, 08:23 PM posted to rec.autos.tech
David
external usenet poster
 
Posts: 2
Default Why would AC only work when foot is on gas?

Trying to summarize the questions from all:

1. I'm not sure if its not turning at idle. The fan is running, but its
just circulating air, there is no cold air coming in.

2. When I rev the gas, then magically cool air comes in.

So, when I'm at a stop light and want to stay cool I rev the engine,
and everyone wonders why a guy in a 1997 rodeo wants to race them.
(hey, at least

One other note - I just had my AC replaced. The folks have a 1 year
warranty. I've heard really good things about them from other people
that have used them. When I first got my car back it worked great for
about 3 weeks then the AC sort of died, I took it back and they fixed
it, but now I have the no air at idle problem.

  #8  
Old August 23rd 06, 09:31 PM posted to rec.autos.tech
Comboverfish
external usenet poster
 
Posts: 644
Default Why would AC only work when foot is on gas?


David wrote:
> Trying to summarize the questions from all:
>
> 1. I'm not sure if its not turning at idle. The fan is running, but its
> just circulating air, there is no cold air coming in.
>
> 2. When I rev the gas, then magically cool air comes in.
>
> So, when I'm at a stop light and want to stay cool I rev the engine,
> and everyone wonders why a guy in a 1997 rodeo wants to race them.
> (hey, at least
>
> One other note - I just had my AC replaced. The folks have a 1 year
> warranty. I've heard really good things about them from other people
> that have used them. When I first got my car back it worked great for
> about 3 weeks then the AC sort of died, I took it back and they fixed
> it, but now I have the no air at idle problem.



I wish I had specific experience with the 97 Rodeo, but some Imports
use an A/C idle up solenoid that increases airflow through the
throttlebody to slightly raise idle speed. Dashpots on the throttle
have also been employed. Typical Import A/C logic is to disengage the
compressor if engine RPM is below a certain point. If the idle up
system was to fail, your compressor would not engage at standard hot
idle speed. It would kick in as soon as you gave the slightest goose
to the gas pedal.

I have noticed this system disappearing on OBDII vehicles, perhaps
because they employ step adjustable feedback idle controls already.
Perhaps your Rodeo still employs an old style A/C idle up system.

Toyota MDT in MO

  #9  
Old August 23rd 06, 11:03 PM posted to rec.autos.tech
John S.
external usenet poster
 
Posts: 981
Default Why would AC only work when foot is on gas?


David wrote:
> Trying to summarize the questions from all:
>
> 1. I'm not sure if its not turning at idle. The fan is running, but its
> just circulating air, there is no cold air coming in.


With the AC on open the hood and look at the compressor.

>
> 2. When I rev the gas, then magically cool air comes in.


When you rev the engine is there a click and slight lugging of the
engine as the compressor clutch engages?

>
> So, when I'm at a stop light and want to stay cool I rev the engine,
> and everyone wonders why a guy in a 1997 rodeo wants to race them.
> (hey, at least
>
> One other note - I just had my AC replaced. The folks have a 1 year
> warranty. I've heard really good things about them from other people
> that have used them. When I first got my car back it worked great for
> about 3 weeks then the AC sort of died, I took it back and they fixed
> it, but now I have the no air at idle problem.


Take it back explain the problem and get it fixed under warranty.

 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
YJ Breaks down - Bad Triple AAA Experience. Lou Boncek Jeep 9 December 18th 05 11:55 PM
Gauges don't work on voyger Dan and Ginny Dodge 5 December 4th 05 05:05 AM
Opinion on work done-price? GrtArtiste Chrysler 4 May 3rd 05 08:56 PM
Accessories don't work in "On" position Chris Fonville Technology 3 April 6th 05 11:33 PM


All times are GMT +1. The time now is 09:27 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 AutoBanter.
The comments are property of their posters.