Engine misfire

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

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

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.

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?

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.

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.

isolated it to #4 cylinder bad fuel injector instqlled all new injectors
running great thanks for your help
dave

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.

finally some good news for a change...

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?

I've overlooked the CEL -get the computer scanned free at Autozone and get back with any code/s

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.

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-

1995 Buick Lesabre Two Wheel Drive
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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!!!

Sounds like a bad Throttle position sensor, or Mass air flow. But when was the last tune up? Air and fuel filters?

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?

Yes it'll caused a hesitation/bogging

It was a faulty computer. Thanks anyway.

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.

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.

Transmission problem
1997 Buick Lesabre 6 cyl Front Wheel Drive Automatic

My car kind of putters when i take off from a redlight or a stop sign...if i let up on the brake and press on the gas very slowly it is normal, but when i do it at a normal pace it jerks for a few seconds then it is normal

Dirty fuel injectors (cleaning the injectors often fixes this).
Bad MAP (manifold absolute pressure) sensor
Bad TPS (throttle position) sensor
Bad or dirty MAF (mass airflow) sensor
Low fuel pressure (leaky fuel pressure regulator or weak fuel pump)
Vacuum leaks (intake manifold, vacuum hoses, throttle body, EGR valve)
Bad gasoline (fuel contaminated with water or too much alcohol)

Sometimes, what feels like a hesitation is actually ignition misfire rather than lean misfire. The causes of ignition misfire may include:

Dirty or worn spark plugs
Bad plug wires
Weak ignition coil
Wet plug wires

My buick is 1990. But I also have that problem. It will jerk a little bit then stop. Then jerk up again. I was wondering if you have had any luck on the comment made by: rasmataz.

If so could you please reply?
I have already got new spark plugs oil change and im thinking about getting a new maf box.

My 1993 Buick Lesabre started showing signs of either a blown head gasket or blown intake manifold gasket. One day out of no where there was a hard continuous vibration on the car, there was thick white smoke coming out of the exhaust, oil level on the dipstick was higher than ever, and coolant was practically gone from the radiator. I tore it all up and i did the following things: had the heads resurfaced (which by the way are made of cast iron, and were checked for cracks), changed the head gaskets, torqued the head bolts to specs, changed the intake manifold gasket and exhaust manifold gaskets, cleaned the injectors with WD-40, new oil pressure switch, new coolant temperature sensor. After a full week i finished putting it back together, and it ran perfectly fine for three days. First thing i noticed the fourth day was a faint wisp of smoke coming out of the dipstick. But someone said it might just be humidity left over in the engine. They told me to run it a bit more and then change the oil again. Then yesterday, I took like a 30 mile drive in the morning and came back home with no problems. One hour later i turn it on to go to work and immediately there's this loud clicking sound which i could've sworn was coming from the valve covers, also there was an immediate loss of power. It would speed to like 20 mph and then it just wouldn't speed up anymore. When i got out of work and i was halfway home, the clicking noise was suddenly gone and was replaced by an actual misfire, with noticeable jerks on the engine and the exhaust pipe. I read online that the clicking sound might be caused by loose rocker arm bolts, so just today i took off the valve covers and there was nothing loose. Every single bolt retained the 25 ft lbs of torque i put. Tomorrow im going to do a compression test to draw more conclusions, but in the meantime does anyone have any ideas as to what it could be? Any advice is appreciated.

may be a bad lifter or a bent pushrod possibly. these engines are known for weak timing chain covers and have poor oil circulation.

I also checked the pushrods and none of them were bent. It might be the lifters which by the way are solid not hydraulic.

they shouldn't be solid as buick has non adjustable rockers on that car unless you have changed them over. t could also be a bad cam start engine with valve covers off and see if all valves are going down about the same. if not check for a bad cam.

Ok well the noise is definitely gone but it still continues to misfire. Another thing i forgot to mention is that when i recently changed the oil again (about a week after the head gasket job) it had tiny metal sludge stuck to the drain plug which has a magnetic tip, and i had never found any metal shavings at all when doing an oil change. So if we take this into account, what else could it be?

hard telling it can be anything

I have a 1997 Buick LaSable with a 3800 engine and have 128,000 miles on the car. After I have been driving about 40-45 minutes in the afternoon the engine starts to chug when I accelerate. For some reason this does not happen at night when it is a little cooler. I took it to a dealership. They replaced the plug wires; intake manifold gasket; and cleaned the fuel system. I still have the problem. No trouble lights show up on my dash board. What could be the problem?

Three things to look at, MAP MAF and Fuel pump...

[quote:4f430d94d4="merlin2021"]Three things to look at, MAP MAF and Fuel pump...[/quote:4f430d94d4]

Thank you for your suggestions. I will have this checked out.

John2

[quote:87921b228a="merlin2021"]Three things to look at, MAP MAF and Fuel pump...[/quote:87921b228a]

MAP? MAF? What do those stand for?

Thanks.

Engine Mechanical problem
1998 Buick Lesabre 6 cyl Front Wheel Drive Automatic 86000 miles

Car was missing, plugs are almost brand new. Checked plugs #1 and #4 were alot darker than the others. #1 and #4 were on the same coil, replaced coil and all plug wires. Seemed to correct the problem for a half mile or so, then car started missing again. Does not seem as often or as bad but still is missing.

Hi there,
Thank you for the donation,

Replace the leads, fit a full set, check air filter and fuel filter if not serviced for some time, run a scan and check for any unresolved fault codes,have a fuel injector service done as well, report your findings here for further assistance,

mark (mhpautos)

Heater problem
1998 Buick Lesabre 6 cyl Two Wheel Drive Automatic 180000 miles

i took the resistor out and took it to a parts store they checked it out and said it was ok. could it be the fan switch if so how do i take it out?????????????????.

Exactly how were they able to test this resister?

You can easily test for the signal coming from the fan switch to the resister using a ground sensing test light.

i have a miss fire, i changed the celinoid,wires,spark plugs, and it still ramdomly misfires. what can i do ?

Go to this link: https://www.2carpros.com/articles/engine-misfires-or-runs-rough

Engine Performance problem
1994 Buick Lesabre Two Wheel Drive Automatic 95000 miles

Engine misses some times at all speeds, when going up a hill or on the enterstate and it misses, i can tromp on it and it stops missing, could this be a ECU unit and if it is can i buy one and install it or dose it need some adjustments, will wait for your comments.