Car stalls when idling when I run the A/C

Tiny
RUDCORRAL
  • MEMBER
  • 2002 NISSAN SENTRA
  • 1.8L
  • 4 CYL
  • 2WD
  • AUTOMATIC
  • 195,000 MILES
When my A/C is running and I'm stopped at a light sometimes my car will stall out it starts right back up. Also sometimes when I am driving when I accelerate it will hesitate like it's not going all the way in gear and will feel like it's going to stall but it does not. But when my A/C is off and I have a full tank of gas it is fine but if it goes below 3/4 of a tank it starts hesitating and stalling again. What could be the problem?
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Friday, July 19th, 2019 AT 7:31 AM

9 Replies

Tiny
JACOBANDNICKOLAS
  • EXPERT
Welcome to 2CarPros.

The first thing I think of when you say it stalls with the AC on is the idle air control valve (IAC). The iac is designed to maintain engine idle speed. There is a idle air volume relearn I want you to try. Normally it is done with a computer, but I was able to find a procedure to do it without. Try this.

________________________________

Without CONSULT-II
1. Turn ignition switch "ON" and wait at least 1 second.
2. Turn ignition switch "OFF" and wait at least 10 seconds.
3. Start engine and warm it up to normal operating temperature.
4. Check that all items listed under the topic "PRE-CONDITIONING", are in good order.
5. Turn ignition switch "OFF" and wait at least 10 seconds.
6. Start the engine and let it idle for at least 30 seconds.

ImageOpen In New TabZoom/Print

7. Disconnect throttle position sensor harness connector (brown), then reconnect it within 5 seconds.
8. Wait 20 seconds.
9. Make sure that idle speed is within specifications. If not, the result will be incomplete. In this case, find the cause of the problem by referring to the NOTE below.

ImageOpen In New TabZoom/Print

10. Rev up the engine two or three times. Make sure that idle speed and ignition timing are within specifications.

NOTE: If idle air volume learning cannot be performed successfully, proceed as follows:

1. Check that throttle valve is fully closed.
2. Check PCV valve operation.
3. Check that downstream of throttle valve is free from air leakage.
4. Adjust closed throttle position switch and reset memory. (Refer to "Basic Inspection".)
5. When the above four items check out OK, engine component parts and their installation condition are questionable. Check and eliminate the cause of the problem.
It is useful to perform "TROUBLE DIAGNOSIS - SPECIFICATION VALUE". See: Computers and Control Systems > Monitors, Trips, Drive Cycles and Readiness Codes > Specification (SP) Value

6. If any of the following conditions occur after the engine has started, eliminate the cause of the problem and perform "Idle air volume learning" all over again:
- Engine stalls.
- Erroneous idle.
- Blown fuses related to the IACV-AAC valve system.

Removal and Installation

IACV-AAC VALVE
Please refer to Engine/Diagrams: See: Engine > Exploded Views > Outer Component Parts

_________________________________

If you need guidance with one of the things listed, let me know.

Take care,
Joe
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Saturday, July 20th, 2019 AT 10:00 PM
Tiny
RUDCORRAL
  • MEMBER
What is the pre condition list is looks like u were sending me links but they didn't come through so I could open them
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Thursday, July 25th, 2019 AT 12:30 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Welcome back:

I am so sorry. I forgot to add the pics. Pic 1 and 2 follow the same order as above. As far as the pre conditioning, here is the list.

PRE-CONDITIONING
Before performing "Idle Air Volume Learning", make sure that all of the following conditions are satisfied. Learning will be cancelled if any of the following conditions are missed for even a moment.
- Battery voltage: More than 12.9 V (At idle)
- Engine coolant temperature: 70 - 95 C (158 - 203 F)
- PNP switch: ON
- Electric load switch: OFF
(Air conditioner, headlamp, rear window defogger)

Let me know if that helps.

Joe
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Thursday, July 25th, 2019 AT 6:04 PM
Tiny
RUDCORRAL
  • MEMBER
What and where is the PNP switch
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Friday, July 26th, 2019 AT 4:27 AM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Welcome back:

See the attached pic.
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Friday, July 26th, 2019 AT 6:20 PM
Tiny
RUDCORRAL
  • MEMBER
Okay, so today my call stalled when I turned into a parking lot. I had to turn it over about 6 times before it started. Now it has the check engine light is on with code p0118.
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Saturday, July 27th, 2019 AT 3:24 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Welcome back:

That code is related to the engine coolant temp sensor (ECT). What makes this interesting is the idea that based on the sensor's signal, the computer determines how rich or lean to make the fuel mixture. It could cause it to stall and not want to start if it is too rich or lean. Now, if you have access to a live data scanner (I assume you have a scanner because you provided the code) I want you to go to live data and check the signal from the ECT. It should indicate the correct engine coolant temperature. If it is way off, replace the sensor.
I attached 2 pictures below. The first shows ECT location in general. The second is more pinpointed.

___________________________

Let me know what you find or if you have questions.

Take care.
Joe
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Saturday, July 27th, 2019 AT 5:55 PM
Tiny
RUDCORRAL
  • MEMBER
It said my coolant temperature is - 40 I know that's not right it is 110 outside.
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Sunday, July 28th, 2019 AT 4:13 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Welcome back:

That's the problem. It's causing the computer to dump fuel to the engine so it can run in that temperature. I have a strong feeling that when the sensor is replaced, the problem will be gone. Lets just hope that the extremely rich fuel mixture didn't damage the catalytic converter.

Let me know if that fixes the issue or if you have other questions.

Take care,
Joe
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Monday, July 29th, 2019 AT 6:37 PM

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