97 Intrepid Cold Start Problems Help!!

[A. Souphound]

Originally Posted by budc

Hi Alvin,
I'm having similar problems with my daughters 95 intrepid. Just changed the battery. Pulled one plug and found it fouled with gas.

Could you tell me where the water and air temperature sensors are?

Thanks.

BudC:
The (ECT) Coolant Temp. Sensor on both the 3.3L & 3.5L are near the Thermostat housing. (Where the top radiator hose attaches to the engine). *Should have a tan/black (+) and a black/blue (-) wires attached.

The (ITS) Intake Air Temperature Sensor/s: 3.3L engine: Mounted in the back of the intake manifold near firewall centerline.
3.5 Engine: Mounted in the intake manifold. You will have to remove the plenum. *Should have a black/red (+) and black/blue (-) wires attached.
*Note wire color code given to help identify sensor/s.
**Same offer I made to Mark stands if you want to check the sensor/s voltage/resistance.

Alvin.

[om4eccv]

I'm having the same problem with a 95 Intrpeid.

After sitting for a day or 2, or during cold weather, it would have to turn over for 20-30 seconds. During that time, it would fire once, but not start. Finally it wouldn't start at all and I had it towed to the mechanic.

Since then, I've had the plugs and wires, ignition coil, and O2 Sensor replaced.

It's been narrowed down to something that is causing the fuel injectors to open for 200ms, instead of the 4ms that it should.

The tricky part is, is that it's not repeatable. Sometimes it will fire and start before I can even release the key. I can try it 10, 30, minutes later, and it won't start.

Any idea what could be causing this?

Thanks,

Chris

[mparks48]

Thanks Alvin,
I found the cold sensor next to the thermostat
(I think) and have the same question as Budc.
Where is the air sensor? I have a digital fluke
meter and will check them at your direction.
However, I'm guessing that I'll only get a bad
reading if the weather is cold and the car wont
start.

Bill,
Did you have any luck with your starting problem?

Mark

[A. Souphound]

Originally Posted by mparks48

Thanks Alvin,
I found the cold sensor next to the thermostat
(I think) and have the same question as Budc.
Where is the air sensor? I have a digital fluke
meter and will check them at your direction.
However, I'm guessing that I'll only get a bad
reading if the weather is cold and the car wont
start.

Bill,
Did you have any luck with your starting problem?

Mark

Mark:
See my answer to BudC. I gave the location of the ITS (Air Temp. Sensor) for both 3.3. & 3.5L. No, it doesn't have to be cold to find a bad sensor.
To check the ECT (Engine coolant temperature) Sensor:
a. With the engine completely cold, remove the connector from the sensor. You will see two pins (terminals) inside the sensor. Check the resistance between the two pins with your VOM. If ambient temperature is around 50F the reading should be approx. 16 - 18K ohms.

b. Start the engine and let it warm up until it reaches operating temperature. (170 -200F) Check the resistance again, the resistance should be lower, between 600 - 900 ohms.

c. Stop the engine. Turn the key "ON" and check the VOLTAGE in the sensor connector by placing the voltmeter on the tan/black (+) terminal and the (-) probe on the blue/black wire terminal. It should read approximately 5.0 volts.
Let me know your results.
Alvin

[A. Souphound]

Mark, Bud, Willy, and All:
CHECKING THE INTAKE AIR TEMPERATURE SENSOR:
The procedure is almost the same as the I described for checking the ECT.
a. With the engine completely cold, remove the connector from the sensor. You will see two pins (terminals) inside the sensor. Check the resistance between the two terminals with your VOM. With ambient temperature approx. 50F, resistance should read approx. 8K ohms. *If temperature is lower, resistance will increase and vice versa).
b. Start the engine and let it warm up to operating temperature (170-200F). Check the resistance again it should be lower, approx. 170 - 20 ohms.
c. Stop the engine. Turn the key "ON" (engine not running) and check the VOLTAGE at the harness connector. Voltage should be approx. 5.0 volts. If the sensor resistance results are incorrect, I would replace the sensor.
Alvin

[mparks48]

Alvin,

The cold sensor test good. Took leave this Friday and will check the air temperature sensor then. The problem is getting the car to cool down during the week. By the time it does it's past my bed time.

Thanks,

Mark

[mparks48]

Alvin,
I believe the air temperature sensor is bad. I get 20k ohms resistance cold vice 16-18k and I'm reading 3.1K ohms resistance vice 600 to 900 ohms hot. 5V check OK. Tempertature was right at 50 degrees F.
Got the part on order and plan to change it out tomorrow. After that, guess we got to wait for a real cold day to see if it will start. Of course that cold day can take it's time coming. Will post an update then. Thanks again Mark

[A. Souphound]

Mark,
Just for clarification: The Intake Air Temp 'hot' resistance reading should have been in the approx. range of 170-20 ohms, and you read 3.1K ohms.
Agreed, sensor should be replaced.
You should see better drivability even in the warmer temperature as the PCM will be calling for a leaner mixture (at runniing temp.) with the new Sensor. I will be watching for your up-date. I agree on the nice weather, it can stay like this till April and then warm up, as far as I'm concerned.
Alvin

[mparks48]

Alvin and all,

This morning the temperature droped to 10 F and my 95 3.5L ES Intrepid would not start. Turned over good but no cigar. This afternoon I got it started by holding the gas pedal in slightly and cranking on it for about 15 to 30 seconds (20 F). Drove it around the block and noticed that the check engine light stayed on. A diagnostics check revaled codes 51, 23, and 22. Both the cold and air sensors are indicated as possible problems and I plan to check them again on Thursday. Also, added a can of dry gas to the fuel tank, just in case there is a gas freezing problem. Will try again in the morning to see if she will start.

PS. Check engine light went out and did not come back on durning sometime while I was checking the engine codes.

[A. Souphound]

Originally Posted by mparks48

Alvin and all,

This morning the temperature droped to 10 F and my 95 3.5L ES Intrepid would not start. Turned over good but no cigar. This afternoon I got it started by holding the gas pedal in slightly and cranking on it for about 15 to 30 seconds (20 F). Drove it around the block and noticed that the check engine light stayed on. A diagnostics check revaled codes 51, 23, and 22. Both the cold and air sensors are indicated as possible problems and I plan to check them again on Thursday. Also, added a can of dry gas to the fuel tank, just in case there is a gas freezing problem. Will try again in the morning to see if she will start.

PS. Check engine light went out and did not come back on durning sometime while I was checking the engine codes.

Mark,
Remove the (-) battery cable for a minute or so, to clear the codes.
The symptoms indicate a 'lean' mixture which you over came by holding the gas pedal in slightly increasing the voltage from the TPS (Throttle position sensor located on the throttle body) and in turn called for a richer mixture.
If you would like to check the TPS: It's much the same as the others:
a. Disconnect the TPS electrical connector. VOM/DMM (+) lead to purple/white wire, (-) lead to black/blue, Key 'On' check reference voltage from PCM should be 5V.
b. Reconnect the connector to the TPS. (+) probe to orange/blue terminal, and (-) probe to ground. With the throttle closed voltage should read 0.5 - 1.0V.
c. Slowly open the throttle and watch the voltage increase to a wide open throttle reading of 3.5 -5V. The transition from low to high voltage should be smooth.
Alvin

[mparks48]

Alvin,
The Intrepid started the following morning (Wednesday) with no problem. The temperature was 15 F. Today I cleared the codes and checked
the TPS sensor as you sugested and it checked
good. I also checked the cold sensor. At
20 to 25 degrees F the resistance was 28K
ohms and when warmed up it change to
about 750 ohms. The car started with no
problem. I attributed the high cold resistance
to colder temperature. I noticed looking at a
schematic drawing of the electrical system
that the tps, ox, coolant and air sensors are
routed through relays (1,3,&5). I'm wondering
if one of the realys might be freezing up in extreme
cold weather. The wiring diagram I've got is not
specific as to which sensor goes through which relay. So I have no idea as to which relay might be causing the problem. Does that sound plausible to you or do you think I'm out in left field?

Mark

[A. Souphound]

[quote=mparks48]Alvin,
The Intrepid started the following morning (Wednesday) with no problem. The temperature was 15 F. Today I cleared the codes and checked
the TPS sensor as you sugested and it checked
good. I noticed looking at a
schematic drawing of the electrical system
that the tps, ox, coolant and air sensors are
routed through relays (1,3,&5). I'm wondering
if one of the realys might be freezing up in extreme
cold weather. The wiring diagram I've got is not
specific as to which sensor goes through which relay. So I have no idea as to which relay might be causing the problem. Does that sound plausible to you or do you think I'm out in left field?

Mark,
Glad to hear your car started, and the TPS checked out O.K.
You said "I also checked the cold sensor. At
20 to 25 degrees F the resistance was 28K
ohms and when warmed up it change to
about 750 ohms. The car started with no
problem. I attributed the high cold resistance
to colder temperature."
Your understanding of Temperature versus Resistance in this sensor is right on!
I failed to see the relays you are speaking of, but I'm not blessed with the greatest diagrams either. You said you cleared the codes, have you had any more 'check eng' indications since then, and how is the driveablilty of the car?
Alvin

[mparks48]

Alvin,
THe intrepid started today (Sunday) with no problem (17 degrees F chill factor 10 degrees F). No check engine light or any other indication of problems. I'll have a chance to start it up tomorrow morning at 5AM an it will be even colder then today. Will see what happens. The engine seems to run smother since the air sensor was replaced. I noticed it most when stopped at a light (in drive).

Mark

[95iceintrepid]

I am having it sounds like the exact same problems as Mark!
I have had 2 o2 sensors replaced as well as plugs and plug wires.
I gave the air sensor info to our mechanic as I am sure these were not things that were checked. I hope this is it! Mark- did you car give you trouble going up hills or sitting in drive at intersections?

[95iceintrepid]

Mark-
What all sensors did you replace?