1995 BMW 325 Warm Start Problems

Tiny
JIMBOZ67
  • MEMBER
  • 1995 BMW 325
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 200,000 MILES
Car sat idle for about 10 months (started fine and ran great at that time) Now, the car starts easily when the car is cold. Once the car runs for a while, it will crank and crank only starting occasionally. We have replaced the ECM, Fuel Pump, Fuel Filter and Fuel Pressure Regulator and continue to have problems. Once it starts, it runs great. Need to figure out the warm starting issue.
Monday, July 20th, 2009 AT 11:37 PM

3 Replies

Tiny
DR LOOT
  • MECHANIC
  • 2,311 POSTS
Ok, without more information, I can only narrow my guess down to a few possibilities.

First guess: coolant temperature sender. When the coolant temperature circuit opens, the DME thinks the car is experiencing -40 degree weather, so it floods the car with fuel to try to get it to start. When the car is cold, the car will start, but after it is warm, the heat of the engine will vaporize the fuel and make the mixture too rich to fire (flooding).

Second guess: crank sensor. I've seen crank sensors with intermittent connection. Temperature and vibration play a role in whether or not the crank signal gets through. Without a crank signal, there is no fuel pump activation or spark.

Third guess: injectors stuck open. When they are stuck open, they put in too much gas which leads to flooding when the engine is warm just like a bad coolant temperature sensor.

Good Luck
Dr. Loot's Assistant
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Wednesday, August 12th, 2009 AT 12:59 AM
Tiny
JIMBOZ67
  • MEMBER
  • 2 POSTS
Starting to think I am crazy. I have changed the Coolant Temperature Sensor, Cam Position Sensor, Crank Position Sensor and I also check the injectors as you suggested, still no luck. Something is causing it to flood itself at startup. When we can get it to start, it runs great; full power and smooth idle. When it doesnt start, it just fills the area with gas fumes. Any additions thoughts or ideas?
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Thursday, August 20th, 2009 AT 10:54 PM
Tiny
DOCHAGERTY
  • MECHANIC
  • 9,603 POSTS
Inspect the injectors for leakage when warm, if there are leaky injectors they can cause this hot soak/no start issue. If you need more assistance let me know.
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Friday, August 21st, 2009 AT 12:30 AM

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