1999 Dodge Stratus Dying when reaches operating temp

Tiny
DFCT
  • MEMBER
  • 1999 DODGE STRATUS
  • 4 CYL
  • 2WD
  • AUTOMATIC
  • 70,000 MILES
Hello guys, just replaced my fuel pump but a new problem appeared.

After engine reaches operating temp, it will begin to drop RPM @ idle, stumble and in a few moments will stall (will not start back until cools down).
before reaching op. Temp, it runs perfectly.

When it fails to start, I did a test at ign. Coil and fuel injectors harnesses; they are NOT receiving power (could be not receiving +12v from ASD relay, or not receiving ground from PCM.)

also, fuel pressure seens fine (by pressing schrader valve); but will get a gauge to test it correctly.

Any tips on what's causing this? I thought about the crankshaft pos. Sensor, but would it fail only when hot?

Thanks!

Oh and check engine is not lighting up!

(stratus 1999 2.0 4 cyl / autostick)
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Saturday, April 25th, 2009 AT 11:59 AM

4 Replies

Tiny
CARADIODOC
  • EXPERT
Thank you for providing a lot of good observations. When you tested for voltage from the ASD relay, where you cranking the engine? You should get the 12 volts to the coil(s), injector(s), fuel pump or pump relay, alternator field, and O2 sensor heaters only for two seconds after you turn on the ignition switch, then the relay will turn back off until the engine computer sees engine rotation, (cranking or running). You might be able to hear the two-second burp from the fuel pump, but you won't be able to hear it while cranking.

The camshaft position sensor is a likely suspect, and it's very common for them to become heat-sensitive. It's on the driver's side of the head. When the pulses stop showing up at the engine computer, the computer thinks the engine stopped running, possibly due to a crash, so it turns the ASD relay off so the fuel pump won't pump raw fuel onto the ground if a line ruptured. There's also a crankshaft position sensor on the back of the engine, but they seem to cause less problems.

These sensors will usually cut out suddenly, not gradually like you described. Did you install a new pump or a used one? If a used one, it could have a plugged pickup screen. They will cause your symptom, then when it sits for a while, the collapsed screen will slowly expand and allow fuel to pass for a while. They act up more often when the largest volume of fuel is moved, which is, ... COASTING from highway speeds. (This is not the same as the tiny amount of fuel actually flowing through the injectors).

Caradiodoc
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Tuesday, April 28th, 2009 AT 4:19 AM
Tiny
DFCT
  • MEMBER
Thx for the reply!

Yes, I was cranking when tested for voltage.

I did the "failure to start test" described in the FSM (when the car was not starting), and the test showed a defective crank sensor.

(the test consists in using a test light @ positive from asd relay output and negative from battery, while cranking - if light stays on, sensors ok; if flashes, crank sensor bad; if no light, could be camshaft sensor. - Mine had the light flashing).

So I took the sensor off, it was full of oil (mostly in the connectors). Gave it a good cleaning and installed back; but now the car refuses to start even cold (test indicates the same problem - crank sensor).

What do you think? Really the sensor? But why did it fail when I cleaned? Is there anything special to be done when reinstalling?

Thx!
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Sunday, May 3rd, 2009 AT 12:39 AM
Tiny
CARADIODOC
  • EXPERT
The air gap is critical for proper operation. If installed as far as it will go, it could hit the notched wheel on the crankshaft and be destroyed. If not installed far enough, it won't generate a good signal.

New sensors come with a thick paper spacer installed on the end. You push the sensor in as far as it will go, then tighten the mounting bolt. Done. When you crank the engine, the spacer will just slide off.

See the dealer for a spacer. I always cut them in half and saved part of each one to save customers that expense on future repairs.

Caradiodoc
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Monday, May 4th, 2009 AT 10:56 AM
Tiny
DFCT
  • MEMBER
Caradiodoc, mine didn't had a spacer, and I guess new ones for my model dont have it either (as for the pics I've seen in the web).

But I tried reinstalling it, this time applying more pressure on the bolt; and now the car is running great! Even when hot.

Forgot to mention, but the first time I removed it, the bolt was totally loose. Maybe that was causing the problems.

Im affraid of running too much tho, cps could fail anywhere. I guess I will buy a new one to keep as backup.

Thx a lot for the help!
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Tuesday, May 5th, 2009 AT 1:11 PM

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