car dying

Have a '95 Le Sabre with a BIG problem. Please help. Nothing consistent. I could be driving down the hwy. @ 60 mpg or sitting at a stop light, idling, and the car just dies. It did just start right back up, but has consistently gotten worse. Now, sometimes I have to just sit and wait for 30 or 45 minutes before it will start. Then, sometimes, it will just die again or it might keep on running and act as if there is nothing wrong, and I am able to get back home.

Last year we had a new computer, and crank position sensor put in. It seemed to fix whatever problem we had then. But the symptoms are not quite the same this time.

We just changed out the idle speed control motor. Thought that we had it taken care of, but have had the same problems again several times today.

Does it do it when cold or hot or both?

Hi Chris,
I'v'e got the same problem, 96 Lesabre 153k miles, mine started dying for no apparent reason over a year ago. Drives fine then just quits. headlights stay on, guages and idiot lights come on. Some randomness on the idiot lights. Used to be able to shift to neutral and restart on the fly, but now takes longer to restart. Recently (the last two times) after restarting, the car won't idle well. I need to keep the accelerator so the engine turns at about 2500 rpms, then for no apparent reason drops to 2000 rpms, then back up to 2500. This may continue for about 2-3 minutes, when the car gives a little sneeze, and it runs fine, until the next time. Usually happens when the car is warm (20 +miles driving) at lower speeds (40 mph or under) with engine turning between 1800-2000 rpms. No help from the dealer, nothing comes up on the diagnostic history when they plug in to check stuff.

lol

Car dies when it has been running for a while. Sometimes, after only about 10 or 15 minutes. But not when I start it for the 1st time that day. Yesterday, I went to church in the morning...no problems...drove home (only one mile)...no problem. About 10 minutes later, I drove to the store (7 miles)...no problems...was in the store for about an hour...came out and started it...drove about 1 half of a mile...it died on me while sitting at stop light...was unable to restart it...got a pull into a parking lot and sat for 45 minutes....tried to start it several times to no avail...finally, it started and I made it all the way home again. About 2 hours later, I had a meeting, and I made it only 2 tenths of a mile before it died on me. After the 3rd try, it started and I made it the rest of the way to the meeting (1 mile). 2 1/2 hours later, it started with no problems...made it all the way (1 mile) home. Have not tried it yet today.

First, I would make sure there is good fuel pressure. I would carry around a timing light and when it is not starting, put on the timing light and crank it and see if the light is flashing. If it is not, I would suspect the crank sensor, or the ignition control module. If it does flash, suspect the computer. There are a lot of other posts in this forum with that symptom.

Bill, your car sound like it's doing the same thing as ours is. Ours only has 79,000 miles on it though. I think that it must have something to do with a glich in some part that the company hasn't figured out yet and I would not recommend this particular car to anybody else....although, I see them everywhere. ....I don't know....I have already tried changing out the parts that "rustbucket" has suggested...which I appreciate the input...but they haven't fixed the problem. It is still doing the same thing and we have been out the cost of a computer, a crank position sensor, and a speed control motor. Does anyone else have another suggestion?

Bill, your car sound like it's doing the same thing as ours is. Ours only has 79,000 miles on it though. I think that it must have something to do with a glich in some part that the company hasn't figured out yet and I would not recommend this particular car to anybody else....although, I see them everywhere. ....I don't know....I have already tried changing out the parts that "rustbucket" has suggested...which I appreciate the input...but they haven't fixed the problem. It is still doing the same thing and we have been out the cost of a computer, a crank position sensor, and a speed control motor. Does anyone else have another suggestion?

Hi Chris,
The vehicle has failed five times in the past two days. I've got an exorcism scheduled for tomorrow ;) Then a trip to look at either a 2002 GMC truck w/42k or new Honda Element. After reading a bunch of posts on this and other forums, it sounds like a loosing battle with this problem. No one that I've seen said "problem solved" the best was "it went away for a while and now its back". The replacement parts you have described are part of the chase, then its plugs,wires, fuel system replacement, and transmission parts. Jack up the radiator cap and back a new rig underneath it. :) Good Luck.

I'd echo rustbucket comments about checking for spark. Timing lights are by far the easiest way to do it since they clip onto (but don't pierce) a spark plug wire and don't require removing any wires or plugs.

*If* you do not have spark, but the engine is cranking and not starting, there are only a few things that can be the cause, although diagnosing some of them requires a little bit of skill.

(note: these conclusions are from reading the info on my '91; they changed things a little with the '95 but not a lot in this area).

Potential causes of no-start from no-spark with engine always cranking OK and sometimes starting/running fine:
- Bad crankshaft position sensor (or harmonic balancer vanes)
- Bad ignition module
- (unlikely but possible, I would guess) ECM/PCM incorrectly sending "Bypass" control signal to ignition module during cranking (defective ECM/PCM)
- Wiring problem (shorts, breaks, bad grounds, bad connections, etc.)

Don't discount the possibility of a wiring problem. Often that plastic conduit gets brittle and breaks into a million little pieces and exposes the wires to rubbing up against sharp metal surfaces. If you find that this is the case, and replace some of the conduit, make sure you get stuff that is OK at high temperatures - most of the cheap stuff deteriorates rapidly at engine temps.

Also don't discount the possibility of one of your replaced components being defective or going bad early - it happens, and evidently more frequently with non-GM replacement parts. But I'd find a way to actually diagnose the issue instead of replacing stuff all over again.

Are you having other symptoms? (e.g., are there codes stored, is the check engine light on, does the speedometer stop working on and off, engine temp light on, etc.)

I would be suspicious of the fuel injectors. Not able to tell if that is the problem by putting a fuel pressure guage on the rail. I have heard a lot about this particular model. Anybody tried the Throttle Position Sensor? Check for pinched or loose wires under the dash, make sure that the relays are doing what they are supposed to. A quick fix that might work is to disconnect the neg(-) teminal on the battery, and leaving it off for 30 seconds or so, put it back on, and see if it starts up. If that works, and the car actually performs properly for a while, it is a computer problem of some sort. That was the time period that the change to OBD2 was happening, so there consequently may be issues with the computer.

I have the same problem with my 92 LeSabre but now it just won't even start after it stalls. Still can't get answers to it. 3 times 3 different mechanics looked at it, did something or replace something and it would run fine. Then 1 or 2 weeks later it'll die. So it has sat more than anything. Have fuel pressure and good voltage. No spark or power to injectors. So I been told. But it all started out stalling when driving in town or on the highway, and it just got worse from there. and that was alittle over a year ago.

You need to take a look at 2 things here. the starter and the fuel pump. I had the same problem last summer and changed all of the sensors but the car was dying almost at every stop. I had to put the car in neutral and accelerate to keep the engine runing. I changed the fuel pump and the starter since the car is runing fine.

Well, we ended up changing out the crank position sensor again, and we have had no problems since...the other one had a couple of places on it that looked as if it had gotten a bit too much heat, and "bubbled" up somewhat. But other than that, there seemed to be nothing wrong with it. Putting the new one on seems to have fixed the trouble.

Chris,

I'm glad y'all got this one fixed! I am curious where you bought the first crank sensor, as a couple months ago I put a new one on my car and due to it being a Friday (and I needed to fix it ASAP) I bought the replacement part at NAPA instead of getting a GM part (GM would have to order, I would have to wait over the weekend). Normally for something that critical I would only go with a GM part, but....

Anyhow, if anyone here has had this stall-or-no-start-when-warm problem come back after installing a NAPA crank sensor, I'd be curious to know (and after how many miles)...

- GB

I had bought a crank sensor at AutoZone. It didnt fix the original problem, but it did make the car "miss" once in a while at idle. I put the original one back in (it wasnt the problem in the first place).
AutoZone wouldnt take it back, they would only exchange it.

I have been driving our '92 Lesabre lately cause my wife won't touch it. The service engine light comes on and goes out intermittently. The engine gives a kind of a clunk/surge and about 10 seconds later the light comes on and will stay on but may go off later. If/when the light goes off again, you feel a change in the engine before it does so. When light is lit, engine may or may not kill at stoplight, but idle is not smooth and usually very low. Will start up again if it dies, but may die a few times again. Trick is to "brake-torque" like we did back in high school to keep the RPMs up while you shift into gear and get going again. I also noticed that when the light is on, if you lightly tap the accelerator in neutral the RPM goes up to about 1,100 and stays there for a few seconds before slowing coming down. Other times when light is off, the RPM goes up and right back down like normal (very strange). I used the paper clip trick to get a code 34 which in for the MAF sensor. Sounds like I'm going to replace a lot of sensors until I find the right one. If anyone has any ideas, I would appreciate hearing them. Buick should rename this model. How about Lestubborn!

Hmmm... MAF sensors are very expensive...

I have not had mine fail and so can't compare notes on the symptoms. But, the sensor tells the ECM/PCM how much air is flowing through the intake, so the ECM can properly meter the fuel mixture via the injectors. If the MAF malfunctions I would expect the RPM to be affected since the ECM won't be getting the mixture correct.

First, though, check the wiring - look at the three wires going to the MAF sensor and check for any signs of breakage, shorts, etc. Do the "wiggle test" - with the engine idling, wiggle the wiring going to the sensor and see if that affects anything. You can also try tapping (not too hard!) the sensor and seeing if that affects something (if it does, the sensor is probably bad). Also try the "tap test" on the ECM.

If the sensor is bad and you are going to have to replace it anyhow, you might try cleaning it first, *gently*. But be warned - the thing is extremely fragile - a pair of tiny metal elements in very fragile-looking tiny glass tubes. Like other areas of the intake, this area can get covered with soot.

The GM service manual (or an account over at ALLDATADIY.com) will give you a nice diagnostic procedure for code 34. If you have a multimeter, going through a real diagnostic may help avoid the spending of money on an expensive part like the MAF sensor if it ain't broke... (as with any sensor, the code may indicate a problem with the sensor, the wiring, or the ECM itself, and in this case, IIRC the sensor costs twice as much as the ECM).

Hmmm... MAF sensors are very expensive...

I have not had mine fail and so can't compare notes on the symptoms. But, the sensor tells the ECM/PCM how much air is flowing through the intake, so the ECM can properly meter the fuel mixture via the injectors. If the MAF malfunctions I would expect the RPM to be affected since the ECM won't be getting the mixture correct.

First, though, check the wiring - look at the three wires going to the MAF sensor and check for any signs of breakage, shorts, etc. Do the "wiggle test" - with the engine idling, wiggle the wiring going to the sensor and see if that affects anything. You can also try tapping (not too hard!) the sensor and seeing if that affects something (if it does, the sensor is probably bad). Also try the "tap test" on the ECM.

If the sensor is bad and you are going to have to replace it anyhow, you might try cleaning it first, *gently*. But be warned - the thing is extremely fragile - a pair of tiny metal elements in very fragile-looking tiny glass tubes. Like other areas of the intake, this area can get covered with soot.

The GM service manual (or an account over at ALLDATADIY.com) will give you a nice diagnostic procedure for code 34. If you have a multimeter, going through a real diagnostic may help avoid the spending of money on an expensive part like the MAF sensor if it ain't broke... (as with any sensor, the code may indicate a problem with the sensor, the wiring, or the ECM itself, and in this case, IIRC the sensor costs twice as much as the ECM).

I thought those Reatta enthusiasts had it bad! thanks for the input. I'm going to get it in the garage this weekend and take a very long look at all the wiring. After reading some of the other posts, I'm wondering if the crank sensor is acting funny. The thing that confuses me is that this condition comes and goes. It's almost like the engine goes from one phase to another and then back to normal again. Thanks again!