1991 Chevrolet Lumina rough idle, dies.

Tiny
MIKE LUCKEY
  • MEMBER
  • 1991 CHEVROLET LUMINA
  • 3.1L
  • V6
  • FWD
  • AUTOMATIC
  • 152,000 MILES
While driving, the car started running rough and died. Limped it home (only a few blocks running badly). Next day, installed new fuel filter and car ran fine. Drove it around for about 30 minutes, then parked it for about an hour, it wouldn't start. It finally starts then but runs rough and dies. Fuel Pressure is within acceptable limits, and the OBD1 system is throwing no codes. It did however die at stoplights occasionally about a week ago. Also used ether to check for vacuum leaks, and couldn't locate any. Any help would be appreciated, thank you, Mike.
Monday, January 20th, 2014 AT 2:31 PM

6 Replies

Tiny
JDL
  • MECHANIC
  • 16,098 POSTS
What is the fuel pressure spec, just curious? Did you check to see if correct fuel pressure held with key off? If pressure drops like a rock, you have a leak. If idle issues, check anything that has to do with idle system, check the iac and passages.

Check the 02 sensor signal, see if it is running rich or lean. If your running rich, check the coolant temp sensor.
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Monday, January 20th, 2014 AT 3:28 PM
Tiny
JDL
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  • 16,098 POSTS
Just to add, how long since a tune-up?
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Monday, January 20th, 2014 AT 3:31 PM
Tiny
MIKE LUCKEY
  • MEMBER
  • 38 POSTS
Pressure spec 40-47 lbs. Mine41, I did not check to see if the pressure dropped, but I will. It had a new iac @ 129000 and full tune-up @121000. It has 152000 now. Also, wouldn't an 02 sensor throw a code? Thanks much for your help! Mike.
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Monday, January 20th, 2014 AT 5:19 PM
Tiny
JDL
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May not always set a code? My main concern was if your running rich or lean? Anymore 02 sensors are part of a tune-up.
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Tuesday, January 21st, 2014 AT 7:00 AM
Tiny
MIKE LUCKEY
  • MEMBER
  • 38 POSTS
Fuel pressure spec is 41-47 lbs. After a number of tests, it is around 40-41, but I had one test at 38. Also, while running, the pressure is 35 ish. If the car dies, which it does, it goes back to 40, and then after a few minutes bleeds down a bit but very slowly.
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Wednesday, March 12th, 2014 AT 8:59 PM
Tiny
JDL
  • MECHANIC
  • 16,098 POSTS
Your fuel pressure sounds ok. Check for egr and or vacuum leak. Without something to hang our hat on, it's just hunt and peck, for me.
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Thursday, March 13th, 2014 AT 12:15 PM

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