ok, ive had this problem occur before, and it is driving me insane!!

'92 Buick LeSabre Custom, 6-cyl, 3.8.

car was stalling at random. i could be on/off gas, uphill/downhill, engine warm/cold whatever....totally random stalls.

Then, my exhaust broke right before the cat. converter. The car was LOUD, but my stalling issue went away.

I had it into the shop to repair the exhaust and replace a VSS (Vehicle Speed Sensor).

Car ran great when I got it back. For about 2 days. Then the random stalling came back.

I just dont understand what could be causing this. The shops I've taken it to say they can't do anything unless it happens for them, and the check engine light comes on.

anyone?!?!


(This post was edited by bryan_kilco on Jan 19, 2008, 12:46 PM)

HI

Hey if the check engine light comes on,take it autozone or a chain type parts store,they will scan the data/codes for free.
then post code/codes here..we can try to help that way.

Just give more info as well....like when it stalls out,does it restart right away or does it have to sit for x amount of time?

sometimes it starts right back up, other times it wont start for minutes or even days.

ok
see if you can get the codes read first...lets start there...post back results...

many things can cause a random stalling out concern....
when it doesn't restart,see if you can check to see if it has spark and or fuel..

really don't want to throw ideas out until i know the codes or if it has spark or fuel.

but one common problem for these can be crankshaft position sensors....but why spend money until your sure...
start with a code reading and lets go from there...
one of us should be able to help you ....

JIM

ok, i forgot to mention - a camshaft sensor WAS replaced a few months ago. The car didnt stall for about 2 weeks after, then started acting up again. The local mechanic couldnt figure out the problem, and I was tired of wasting money at his shop (he just wouldnt fix things that i would tell him to fix)....so i took it to a different shop just a few days ago. It ran fine for about 2 days, and now it's stalling again.
Maybe a bad cam sensor was installed?!?! The guy at the shop asked if a cam sensor was previously replaced, and i told him yes.....

HEY

lets get the codes if possible...then go from there..
try to find if there is no spark when it doesn't start..
if not....a good scanner with data stream capabilities will be needed to check for cranking rpm...

if you have a dvom,(digital volt ohm meter) measure resistance at the cam sensor and crank sensor when it stalls out....
was the sensor that was replaced new or used?

Haave you had the crankshaft sensor or ignition module checked? Possibly even the coil assembly could be the problem.




http://www.publicsurplus.com/...owse/cataucs?catid=4 <<< Click on link and see our surplus vehicles for sale.
Being way2old is why I need help from younger minds.

well I think it's going back to the shop tomorrow, hopefully they can figure this out. It's been acting up a lot today.....I can't even drive 5 minutes from my girlfriends house to my house without it stalling. what I dont understand is - why did the problem go away when my exhaust was broken?!?!
someone told me it could be a clogged cat. converter...but I also heard that a clogged converters symptoms are misfiring while going uphills/accellerating.

Plugged converters are a possibility. Usually the power will gradually decrease as it is warming up. The warmer the vehicle, the quicker it stalls. In your earlier post you stated it ran good when the exhaust broke. That is a sure test for plugged converter.




http://www.publicsurplus.com/...owse/cataucs?catid=4 <<< Click on link and see our surplus vehicles for sale.
Being way2old is why I need help from younger minds.

Sorry to jump in here but I’d lay money on the crank sensor or a bad connection at the crank.
Why I’m thinking connection is that the camshaft’s and crankshaft’s wiring harness’s run together in the same loom and are relatively close together; unplug one you’re going to disturb the other.
Plus these older 3.8’s were known for crank sensors; try doing what GM calls “simulate road shock” in other words hit the sensor. I don’t mean beat the crap out of it just some light taps. I usually use a long 3/8-drive ratchet extension; with the extension you can (with the engine running) reach down to the sensor and tap on the side of it. If the engine stalls, hiccups anything replace the sensor.
Also have a look at the terminals inside the wiring harness connector; making sure that none of the terminals have spread apart allowing an intermittent connection.
What I’ve done to check the harness (female) terminals for the proper tension; is to take an old sensor or any other connector apart; one that has the same style of male spade terminal that fits the female harness. Take one of the terminals you’ve just salvaged and slide it into the harness terminal you’re checking. You should feel a slight drag and the test terminal shouldn’t fall out no matter how hard you shake the harness.
As for why the car ran ok with the broken exhaust is likely the under hood temperatures were much lower, due to the lack of backpressure, that the exhaust normally creates.
All of the suggestions given here are worth printing off and taking in to the repair shop you’re going to deal with. Most any good technician would at least read it and it might give them a new way of looking at the problem?

Dan.

Canadian "EH"

In Reply To

I didn't think it was that great of a post that it needed repeating. LOL

Dan

Canadian "EH"

haha sorry I tried to quote you but for some reason the question I asked didnt show up....

where is the sensor/harness located? is it the thing that is plugged into the front of the coil pack/ign. module?

I just found out that I can't get it to the shop until NEXT monday, so im a bit stressed now......I need to be able to get around, as I'm in a band and we have a show coming up this week. Not good.

Quote

No that’s the ignition module; you’ll find the crank sensor and its wiring harness connected to it, below the module at the crankshaft pulley.
But if you’re thinking of replacing the crank sensor, you’ll likely need a puller and a sensor-locating (positioning) tool to do it. The crankshaft pulley needs to be removed before the sensor will come off.
Besides that there are more tests that can be performed before condemning the sensor.
I would wait until you can get the car in for diagnosis. Maybe rent something to drive for your show; there must be someone in your area that has a rent a wreck or ugly duckling used car rental business?

Dan.

Canadian "EH"

yeah, Im just going to wait to get it checked out.
I'm sure I'll find a ride to the show somehow.
I simply cannot afford to rent anything, I have been out of work for about 3 weeks now....not good.

Thanks for all the help, guys! I greatly appreciate it!!

Hey Dan. Always willing to have you jump in. About all I can offer on other than F--- is generic or look at diagrams and hope for a lucky guess. Good to see you are still around.




http://www.publicsurplus.com/...owse/cataucs?catid=4 <<< Click on link and see our surplus vehicles for sale.
Being way2old is why I need help from younger minds.

The new shop here keeps me busy during the day and with me falling asleep right after supper in the evenings is the biggest reason for not seeing as much of me lately. LOL
Today’s kind of a slower day and I’ve had some time to play; the tec’s are wondering why I’m staying in my office, instead of getting involved with the repairs?
I asked/told the youngest guy here; that after twenty five more years then him of pulling wrenches, is why I’m sitting down; what’s his excuse for dragging his A$$?
He didn’t know what to say and went back to work; at times its good to be the boss. LOL

Dan

Canadian "EH"

what do you have for a tranny, is it a 4 speed or a 3. i had a GM with a 3 speed that the lock up switch was f---ing up and made the car stall out. when it was cold / hot some times 1 a day and other time 6, 7, 8, and all types of road condition.

its a 4 speed.
1 2 D OD

well ive been driving it here and there while i wait to get it to the shop.

seems as though once it stalls a few times, it starts running poorly as well....misfiring/sputtering when accelerating.

Yesterday morning I made it to work fine, didnt stall once. Today it stalled within 2 mins of driving. AHHH!!!!

ok, so she's back in the shop and the mechanic called and said the only error code that came up was the Mass Airflow.

He changed it and I am waiting on a ride to go pick it up.

I REALLY freaking hope my problem is solved..... =/

got it back and so far, so good. no stall on the way back home.

hopefully she stays good!

In Reply To

I have come across one mid 90s pontiac where the prob was a transmission sensor we had heck finding it till the sensor actually burt melting some of the harness wires . gave intermittent cutting out etc .

wow, just my luck. problem still remains. =/

its back at the shop. the mechanic took it for a ride with me in it, and it didnt stall for him. ALMOST did....it like stalls, but then kicks in right away and keeps going. I left it at the shop and they are going to continue to drive it around and see if they can figure this hellish nightmare out.
this is totally insane.....Hundreds of $$.....for parts that arent fixing my problem.

I've done tons of online research here, and on the Buick forums.....most similar problems point to crankshaft position sensors....but wouldnt that make the check engine light come on all the time?


(This post was edited by bryan_kilco on Jan 29, 2008, 2:49 PM)

No not necessarily, if the sensor is giving out a signal but an erratic signal, it may set a code.
If the signal just stops as in the sensor or sensor circuit goes open; the computer assumes that the crank has stopped rotating and in turn, shuts down the rest of the system.

Dan.

Canadian "EH"