Mechanics

SERVICE ENGINE SOON LIGHT - STALLS & SPUTTE

1990 Buick Lesabre

My wife's 1990 Buick LaSabre with 148,000 miles on it is being quite evil right now. : Evil:

Don't know if this has anything to do with its issues, but when she let the car get down to 1/4 tank of gas, it'd start sputtering, she'd fill it up, and things was fine again. Last Friday this happened, only things weren't fine anymore. The Service Engine Soon light came on and off, and on and off, and so-forth. As the car is driven more, it will sputter and stall more. (Also, she thought she smelt fuel once and awhile during the past month, but nothing leaked on the ground. Also, the vent switch started working and not working. With warmer air coming out sometimes. And it'd work again if car wash shut off and turned back on).

Two readings at two different auto parts stores gave a reading of 34 - mask air flow sensor. I installed a new one, unhooked the battery for awhile for computer to reset, hooked it back up, turned on car and. Yep. Light was back on and it was still running rough. (I took the part back and put old one back on).

I did a tune-up, new oxygen sensor, idle air control valve, the harmonic balance sensor, additive in gas. The LeSabre is not only evil, I could swear it's laughing at me in the driveway. : Twisted:

So, any ideas on what else to check?

Thanks in advance for all input

John
Avatar
John_and_Annie
July 10, 2006.




After 4-days of trying to fix this beast, I finally got it working. Knock on wood. And hope it stays that way. I'm responding to my on question, so if others run into a similar problem, perhaps it'll help them. Here's everything I did to the car.

Changed spark plugs and plug wires.
Changed oxygen sensor
Changed harmonic balancer sensor
Changed air filter
Changed air filter housing the air temperature sensor
Changed the engine coolant temperature sensor
Changed the mass air flow sensor
Used injector cleaner
Change PCV valve
Changed idle air control valve
Cleaned EGR and lubed it
Changed EGR gasket

Most parts were new, but I bought a used mass air flow sensor. It cost about $400 to do all this and a lot of frustration in ruling things out. But the " service engine soon" light is not on and the car is not sputtering or stalling out. Lord willing, it'll stay that way for some time to come.

Have a great day!
8)

John

Tiny
John_and_Annie
Jul 12, 2006.
Any idea what fixed it?

Was it the egr valve, did you do that last?

Tiny
Xowey
Jul 13, 2006.
The Mass Air Flow Sensor stopped the " service engine" light from coming on, as well as stopped the car from stalling when test driving it.

However, there still was a periodical shake to the car when test driving it. After cleaning and lubing the EGR, as well as replacing the EGR gasket, on the next test drive the car stopped shaking. The EGR desperately needed cleaned.

It's been 3-days and the car's been driven quite a bit. So far, all is well (again, knock on wood). : D

Likely the MAFS and EGR were the 2-major problems. However, the car was overdue for a tune-up, oxygen sensor, and an air filter. It seems to have more " get up and go" to it now.

In the earlier stages of working on the car, I discovered the PCV valve was cracked, so obviously that needed replaced.

I don't know how much difference the harmonic balancer sensor, idle air control valve, gas and injector cleaner made.

Hope this helps some!

8)

Tiny
John_and_Annie
Jul 14, 2006.
[/b]Almost forgot. Yes, changing the mass air flow sensor was next to the last thing I tried doing to fix the car. The last thing I did to the car was clean and lube the EGR and replace the EGR gasket. I did all the other stuff before doing these last 2-things.

Have a good day!

John

Tiny
John_and_Annie
Jul 14, 2006.
Looks like you fixed it and did some preventative maintenance too. Great job! : )
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Tiny
Xowey
Jul 14, 2006.

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