Engine misfire

Tiny
CTWEEKLEY
  • MEMBER
  • 1995 BUICK LESABRE
I HAVE A 95 BUICK LESABRE WITH 165,000 MILES ON IT-IT IS JUMPING WHEN I ACCELERATE-IS THIS A SPARK PLUG PROBLEM? OR COULD IT BE SOMETHING ELSE
Monday, July 9th, 2007 AT 9:29 AM

44 Replies

Tiny
BPRICE443
  • MEMBER
  • 66 POSTS
I think your on the right track with spark plugs or wires. It could be a number of different things but it,s probably a spark plug wire arching. I would change all plugs and wires.

Here is a guide that will help you fix the problem

https://www.2carpros.com/articles/engine-misfires-or-runs-rough

Brian
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Wednesday, July 25th, 2007 AT 12:31 AM
Tiny
GAVIN1
  • MEMBER
  • 6 POSTS
  • 1995 BUICK LESABRE
  • 6 CYL
  • FWD
  • AUTOMATIC
  • 15,000 MILES
Engine Mechanical problem
1995 Buick Lesabre 6 cyl Front Wheel Drive Automatic 150, 00 miles

new plugs and wires have replaced coil paks engine still has a minor miss noticeable most often at highway speeds when tranny is in overdrive.
Some times at slow acceleratinn solw traffic 3-5 mph it is almost like a small lurching feeling.
Making me crazy I heed help
proble is now getting worse and occurs at any speed or RPM engine never stalls
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Saturday, September 30th, 2017 AT 4:24 PM (Merged)
Tiny
BUDDYCRAIGG
  • MECHANIC
  • 2,262 POSTS
I would start by doing a load balance test to see if you can narrow it down to one cylinder.

You need a low RPM tach/dwell meter that you can get at most part stores for about 10 bucks.
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Saturday, September 30th, 2017 AT 4:24 PM (Merged)
Tiny
GAVIN1
  • MEMBER
  • 6 POSTS
Buddy thanks for your reply
i have a balkamp dwell tach model 4-4700 left over from the old days of coil and points red and black leads. Dont understand how to hook up to coil packs or what to do to load balance system. Could you clarify?
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Saturday, September 30th, 2017 AT 4:24 PM (Merged)
Tiny
BUDDYCRAIGG
  • MECHANIC
  • 2,262 POSTS
A load balance test is you watch the RPM.

Disconnect the IAC.

Then removed on spark plug wire, make note of any change in RPM, and reconnect the spark plug.
Do this for all of the plugs.

The one that does not make a change, or little change in the RPM is the weak cylinder.
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Saturday, September 30th, 2017 AT 4:24 PM (Merged)
Tiny
BUDDYCRAIGG
  • MECHANIC
  • 2,262 POSTS
And I think you want to tap into the purple/white wire. But do so at your own risk.

You are always taking a chance at blowing out some solid state electrical device.
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Saturday, September 30th, 2017 AT 4:24 PM (Merged)
Tiny
GAVIN1
  • MEMBER
  • 6 POSTS
Isolated it to #4 cylinder bad fuel injector instqlled all new injectors
running great thanks for your help
dave
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Saturday, September 30th, 2017 AT 4:24 PM (Merged)
Tiny
LLOYD LOBERGER
  • MEMBER
  • 5 POSTS
  • 1995 BUICK LESABRE
  • 6 CYL
  • FWD
  • AUTOMATIC
  • 100,000 MILES
Engine Performance problem
1995 Buick Lesabre 6 cyl Front Wheel Drive Automatic 100000 miles

I've had this car to 2 good mechanics. I've had them take it home and drive it themselves.
Intermittent misfire. Sometimes nearly stalls out. Then runs fine for awhile. They replaced oxygen sensor, module, plugs and wires, mass air flow sensor, fuel filter, catalytic coverter, temp sensor, cam sensor, cleaned injectors. "Check engine" light stays on all the time but it did that even when the car was running fine. This happens at highway speeds or any time. Starts good.
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Saturday, September 30th, 2017 AT 4:24 PM (Merged)
Tiny
BUDDYCRAIGG
  • MECHANIC
  • 2,262 POSTS
Finally some good news for a change.
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Saturday, September 30th, 2017 AT 4:24 PM (Merged)
Tiny
LLOYD LOBERGER
  • MEMBER
  • 5 POSTS
I have this car at home now. It starts and idles fine now. Fuel pressure test OK. When I open the throttle it runs good to 700 rpm then begins to lope badly (about once per second). Which is what it does now on the highway. Fuel pressure holds steady at 35 psi. Down from 40 psi at idle. Where should I look next?
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Saturday, September 30th, 2017 AT 4:24 PM (Merged)
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
I've overlooked the CEL -get the computer scanned free at Autozone and get back with any code/s
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Saturday, September 30th, 2017 AT 4:24 PM (Merged)
Tiny
LLOYD LOBERGER
  • MEMBER
  • 5 POSTS
The Autozone guy said the only code recorded shows a misfire problem. Bad spark plug, wire or something like that. Incidentally, the car ran fine on the trip to Autozone, 28 miles roundtrip, both city and highway driving.
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Saturday, September 30th, 2017 AT 4:24 PM (Merged)
Tiny
RASMATAZ
  • MECHANIC
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It'd be nice if they can identify the misfire/s code-its just probably an intermittent-If it just a cylinder misfire check the sparkplug, compression and injector for that cylinder. P0300 Random misfire P0300-could be caused by vacuum leaks and bad fuel-
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Saturday, September 30th, 2017 AT 4:24 PM (Merged)
Tiny
TAMMI WIDENER
  • MEMBER
  • 1 POST
  • 1995 BUICK LESABRE
1995 Buick Lesabre Two Wheel Drive

My 1995 Buick Lesabre has started chugging. It started in town and then when I took it out on the highway it was so bad the car was jerking. I noticed that when I take my foot off the gas it is fine or when I put the gas pedal all the way to the floor it doesn't do it. Help!
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Saturday, September 30th, 2017 AT 4:24 PM (Merged)
Tiny
MERLIN2021
  • MECHANIC
  • 17,250 POSTS
Sounds like a bad Throttle position sensor, or Mass air flow. But when was the last tune up? Air and fuel filters?
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Saturday, September 30th, 2017 AT 4:24 PM (Merged)
Tiny
LLOYD LOBERGER
  • MEMBER
  • 5 POSTS
The Autozone guy said that if the car was built before July 1995, a lot of that stuff wouldn't show up in the trouble codes. I'm starting to think it's something like a loose connection in the control system that closes and opens with vibration or something, etc.
I'm trying a new mechanic who says he's worked on lots of LeSabres for 10 years. He's pretty confident he can diagnose and fix it. I'll let you know.
Just a thought, could the symptoms you describe in your last reply cause the problems I reported on Oct. 5?
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Saturday, September 30th, 2017 AT 4:24 PM (Merged)
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Yes it'll caused a hesitation/bogging
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Saturday, September 30th, 2017 AT 4:24 PM (Merged)
Tiny
LLOYD LOBERGER
  • MEMBER
  • 5 POSTS
It was a faulty computer. Thanks anyway.
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Saturday, September 30th, 2017 AT 4:24 PM (Merged)
Tiny
HAROLD WOLFE
  • MEMBER
  • 2 POSTS
  • 1994 BUICK LESABRE
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 90,000 MILES
Engine Performance problem
1994 Buick Lesabre 6 cyl Two Wheel Drive Automatic 90,000 miles

engine misses when idling, going up a hill or down a hill, I can go between fifty and higher and it will miss, tromp down on excellerator and the missing will stop, could this be a ecu unit.
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Saturday, September 30th, 2017 AT 4:24 PM (Merged)
Tiny
SERVICE WRITER
  • MECHANIC
  • 9,123 POSTS
It's possible, but I would first get a fuel pressure gauge on it and get it up to the windsheild to see it. Drive it and see if the pressure drops when the symptoms occur. I would lean towards a fuel pump unless the test is negative.
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Saturday, September 30th, 2017 AT 4:24 PM (Merged)

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