ROUGH/LOW IDLE WHEN COLD (95 SE VIN K)
#1
ROUGH/LOW IDLE WHEN COLD (95 SE VIN K)
I NEED SOME HELP FINDING A PROBLEM. WHEN COLD, IT WILL NOT IDLE FAST ENOUGH TO KEEP RUNNING. ENGINE HAS HAD A LOT OF RECENT UPDATES. PLUGS, WIRES, COILS, INJECTORS, IAC & TPS. ONCE THE CAR WARMS UP IT RUNS JUST FINE. I DON'T HAVE AN ENGINE CODE THAT IDENTIFIES A PROBLEM. COULD THERE BE A AIR OR COOLANT TEMP SENSOR THAT IS NOT TELLING THE COMPUTER TO UP THE IDLE SPEED UNTIL THE ENGINE WARMS UP? IS IT A VACUUM LEAK THAT SEALS UP WHEN THE ENGINE WARMS UP?
#2
Senior Member
True Car Nut
All caps is equivalent to yelling. Please don't do that.
Yes, it is possible that either the intake air sensor or the coolant temperature sensor is faulty. You may also want to check fuel pressure. A vacuum leak will usually cause the car to idle more quickly, not more slowly. The IAC would be also suspect if you had not just changed it. You cleaned the passages in the throttle body, right?
Also, check the pcv valve to make sure it is not stuck or frozen and that the pcv o-rings are in place.
If you have access to a scan tool, you can compare the "temperature" output of the Intake Air Temperature sensor with the Coolant Temperature Sensor when the car is cold directly. Otherwise, use an ohm meter and measure the resistance of each when the car is cold. According to the Chilton'* manual, they should be nearly the same.
Here is the chart for both the coolant temperature and intake air sensor from Chilton 28200:
Degrees F.......Ohms
212...................177
194...................241
176...................332
158...................467
140...................667
122...................973
113.................1188
104.................1459
95...................1802
86...................2238
77...................2796
68...................3520
59...................4450
50...................5670
41...................7280
32...................9420
23.................12300
14.................16180
5...................21450
-4..................28680
-22................52700
-40...............100700
Yes, it is possible that either the intake air sensor or the coolant temperature sensor is faulty. You may also want to check fuel pressure. A vacuum leak will usually cause the car to idle more quickly, not more slowly. The IAC would be also suspect if you had not just changed it. You cleaned the passages in the throttle body, right?
Also, check the pcv valve to make sure it is not stuck or frozen and that the pcv o-rings are in place.
If you have access to a scan tool, you can compare the "temperature" output of the Intake Air Temperature sensor with the Coolant Temperature Sensor when the car is cold directly. Otherwise, use an ohm meter and measure the resistance of each when the car is cold. According to the Chilton'* manual, they should be nearly the same.
Here is the chart for both the coolant temperature and intake air sensor from Chilton 28200:
Degrees F.......Ohms
212...................177
194...................241
176...................332
158...................467
140...................667
122...................973
113.................1188
104.................1459
95...................1802
86...................2238
77...................2796
68...................3520
59...................4450
50...................5670
41...................7280
32...................9420
23.................12300
14.................16180
5...................21450
-4..................28680
-22................52700
-40...............100700
#3
Sorry about the caps. I have to use caps for all my data entry at work and just hadn't changed it.
I do have a scan tool, so I will check the temp comparison of the sensors. I just installed a new thermostat and I have noticed the temp guage fluctuates between 195 and 220. Thought I had air in the system, but no air comes out of the bleeder and the coolant level is full. I will post results tomorrow. Thanks.
I do have a scan tool, so I will check the temp comparison of the sensors. I just installed a new thermostat and I have noticed the temp guage fluctuates between 195 and 220. Thought I had air in the system, but no air comes out of the bleeder and the coolant level is full. I will post results tomorrow. Thanks.
#4
Senior Member
True Car Nut
Originally Posted by PANAMA63
Sorry about the caps. I have to use caps for all my data entry at work and just hadn't changed it.
I do have a scan tool, so I will check the temp comparison of the sensors. I just installed a new thermostat and I have noticed the temp guage fluctuates between 195 and 220. Thought I had air in the system, but no air comes out of the bleeder and the coolant level is full. I will post results tomorrow. Thanks.
I do have a scan tool, so I will check the temp comparison of the sensors. I just installed a new thermostat and I have noticed the temp guage fluctuates between 195 and 220. Thought I had air in the system, but no air comes out of the bleeder and the coolant level is full. I will post results tomorrow. Thanks.
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