My wife's 97 Lesabre will die infrequently. When it happens, she puts it in neutral and it restarts immediately. This has been happening for a long time now, maybe 2 years; however, it could go many months without occurring at all. It first happened on a bumpy section of curved road. It now is happening on a hill (same hill). It does not do it every day, but it will happen in a similar spot. I do not know if there is a bump there, or if the slope has something to do with it.

There are no codes. I am ruling out the crank pos sensor and crank angle sensor. I would think there would be a code. Also, it is not heat related.

I just (today) cleaned and tightened the grounds near the computer and near the battery. I cleaned and tightened the battery cables as well.

I have read there is a buss connection on the driver's side that is problematic and may cause intermittant dying. Does anyone know exactly where this connection is located? I would like to clean it up and make sure all is tight and well grounded, but I do not know where to look for this connection.

Does anyone have any other ideas regarding this problem? There are no codes, so I suspect it is a ground or loose connection that separates due to a bump in the road or the hill. I tend to think it is electrical rather than fuel related (at this point) Thanks.

Under the ft l/s carpet just inside the sill plate, a series of white gd wires at a multiple junction, a problem here can kill the fuel pump.

Thanks. I now have the sill loose and the wires exposed. I am on the driver's side, looking under the sill where the mass of wires run through. The wires are in a group that is kind of tucked under the sill edge. The entire group or mass of wires is about an inch in diameter. There are only 2 white wires in the entire mass.

There is a series of black wires that join in a black plastic coupler. It has a blue piece of plastic on the end. Could it be that the ground sires are black rather than white in the multiple junction or are the white wires elsewhere. I have jiggled this connector with the engine running and, so far, the engine continues to run. It is kind of wet near the wiring. We had some rain this past week and it seems water is getting in there somehow. Thanks.

Yes, it's actually the black wires. Check the passenger side also.

Thanks. Just came back in. I see the black plastic multiple junction (about 3 or 4 inches long). It has about 5 wires going into it that all make contact on the metal piece. I removed the plastic end and slid out the long metal piece which did kill the engine. I sanded it some to clean up the contacts. All-in-all, it looks like it is in fairly good shape. I pieced it back together and tucked it all back up under the sill. It would start with the metal piece out, but would not stay running.

There is a similar buss on the passenger side? I'll take a look on that side too.

When does it stall? Is she going up the hill or down?

She's not home at the moment to ask, but I am fairly sure she is going down hill because she says she throws it an neutral and restarts it...like she is coasting still and restarts. I'll check for sure though.

The other spot where it has happened, it is relatively level, but is a sharp curve and the road is bump from breaking which kind of rattles the car.

The buss on the right side only has 2 ground wires. If I removed the metal piece, making the ground incomplete, the car stays running. Cleaned off well and put it back together.

I drove it quite a while and it ran fine. We'll just have to see how it does now. Maybe it will improve I am wondering if there are any other critical ground connections or fuse connections that could be causing the problem? If so, I would go ahead and check them out. Thanks.

My wife says it dies going down hill when her foot is off the accelerator. She said it will do it sometimes when coasting up to a light, on the level, with her foot off the gas. She said it never dies when she has her foot on the gas accelerating. She said it just quits though when her foot is off the gas. Could that possibly be the throttle position sensor?

I think that makes it less likely to be an electrical problem & more likely just an idling problem. I'd start by removing the IAC & cleaning that & where it seats in the throttle body. Use a sensor safe throttle body cleaner & Q-tip to reach into the throttle body. You might also want to remove the throttle body & give it a good cleaning.

Also check for vacuum leaks. I'm sure the rubber hoses on a 97 are getting hard & brittle.

Will do. I'll clean it up in the morning. I have some electrical component cleaner that is sensor safe. I am fairly sure I have some MAF sensor cleaner too. I drove it again this afternoon and it ran just fine. It could be a vacuum leak. I have never looked them over too closely. The car has always run so well, I haven't worried about it much. Thanks.

It died again today on the same hill. She said it is a fairly steep grade (downhill). Her foot is off the gas and it quietly dies. She says it is tricky because there are no power brakes and no power steering, etc. She puts it in nuetral and it starts immediately (no hesitation). It is a fairly smooth road but a steep down hill grade. The hill seems to be significant to it dying.

I looked at it again tongiht. I did not find any vacuum leaks. The hoses look fairly good. I cleaned the MAF sensor with MAF sensor cleaner. It was very dirty. I lubricated the linkage real well. The idle seems fairly good. I am thinking it is the slope for some reason that triggers it to die. I drove it around and around tonight and it ran just fine. Any ideas are appreciated.

I am thinking maybe a blocked sump in the tank or a baffle out of place. It starts up immediately following. Possibly, a bad fuel pump, or bad fuel pump relay, a bad ground to the fuel pump--if not the idle problem. Something related to the downhill grade.

I know this was a totally different automobile...no computer, not much of anything, but I had the same problem with a 75 Chevy Vega. (what you say?)
I would be driving along and it would die. This would only happen at highway speeds. Sit on the side of the road for a minute or two and it would start right up. My problem was a blocked vent in the fuel cap. I guess this created a small vacuum in the tank when the car need fuel the most. Replaced that gas cap and problem disappeared.


Again, totally different car, (if you can call that thing a car) and different era. Perhaps a code would be generated if this happens in newer vehicle, but I though I would mention it.

I remember riding in a Vega once. Didn't Vegas blow up when rear ended? It's funny you should mention the gas cap problem because I read something about a vacuum in the tank causing this situation just last night. I will research that further and check out the gas cap. I don't see how you ever figured out it was the gas cap causing the problem. My sister had some fuel problem with a VW Beetle. She drove VWs for years. It would vapor lock and we had to suck gas out of the tank with a hose and prime the carb. Problem was it was hard to do this without getting gas in the mouth.

My wife said her Lesabre did not die today. She said she just kept her foot on the brake all of the way down the hill so it wouldn't die. I asked her if she really thought that helped. She said it only seems to die when she has her foot on neither the gas or brake when coasting. I doubt there is much to the foot on the brake. Thanks.

I remember riding in a Vega once. Didn't Vegas blow up when rear ended? I don't see how you ever figured out it was the gas cap causing the problem.

It was the Ford Pinto that used to explode when hit in the rear. We used to joke that one of the Pinto's options should be an asbestos suit:grinyes: As for figuring out the gas cap was the problem, my girlfriend at the time lost the gas cap, I picked up another, (cap not girlfriend) and the problem went away.
Someone said the vent in the old one must have been blocked.
Anyway, good luck with your problem. :)

That's right. It was the Pinto that had the gas tank problem. I wish my wife would accidently fix this problem. I have 2 Lesabres and was going to swap the gas caps on them last night to see if that changed anything. I then remembered the caps are held on with that plastic thing to keep from losing the cap. If it is still dying, I'll look at it closer over the weekend. Thanks.

That's right. It was the Pinto that had the gas tank problem. I wish my wife would accidently fix this problem. I have 2 Lesabres and was going to swap the gas caps on them last night to see if that changed anything. I then remembered the caps are held on with that plastic thing to keep from losing the cap. If it is still dying, I'll look at it closer over the weekend. Thanks.

Hello

Vehicals 1996 and newer (maybe even older) do not have a vented gas cap. Instead the tank is vented to a carbon caniter which holds the gas fumes until the engine is started and the the fumes are burnt.

Regards

Dan

also try the fuel pressure regulator. friend had one that kept dying all over town, 5 mechanics couldnt find the problem, 6 was the charm. changed out the fuel pressure regulator and no more problems.

Thanks. The fuel pressure regulator was listed as one of the engine problem areas on the MSN Auto site. Also, the crank and cam position sensors and , I think, the upper plenum problem-some other items which seemed to hold true.

Depending on how the car does in the next few days (it hasn't died for the last 2 days), I will relieve the pressure and take it out and clean it or replace it. I have not replaced it in this Lesabre, but I did in my other one years ago. I still have the old one out of that car. I am fairly sure that part is still good.

It had not died at all for days and then, today, it died 3 times. It died on my wife twice on down hill curves. I drove it this evening and it died on me in town, after a slight down hill grade. It leveled out at the bottom, then died. There was a lot of traffic and a light. It was very difficult to brake hard enough to avoid rear ending the car in front that was also braking.

My wife will switch over to a different car for a few days. I noticed a red light lit up on the dash when it died. I did not catch what it was for sure. It was staight ahead, slightly right. It restarted easily. Would this be the alternator light? After starting and driving a bit further, I noticed the alternator gauge needle dropped slowly all of the way down to 13 momentarily. It then returned to charging at what looks like about 15 volts, but maybe it is not quite that high. Would an alternator going bad intermittantly result in a dying situation? I think the light may have been the alternator light. It may need an alternator. I have never replaced it since we have had the car. It has right at 150,000 on it. It had about 103,000 when I bought it. Thanks

I am fairly sure it is electrical at this point. I have never replaced the cam and crank sensors in this car, so maybe I will go ahead and swap them out. It has 150,000 on it, so they are pobably due. They seem to be a problem area.

I have had a similar problem for the last few months. It has only died 3 times now but sometimes coming to a stop you can watch the tach drop RPM's quickly and then recover, sometimes it does it 2-3 times (drops) and when you come to a stop everything is fine. Sometimes it will drop and kill the engine. It always happens when you are braking coming from a speed of 30+mph. Sometimes the SES light will go on and I drive right to the mechanic. Turn the car off and hook up the Snapon scanner/computer, turn the car back on and the SES light is no longer lit and there are no trouble codes showing.

Friend of mine says he believes it is the alternator. Since I replaced it 5 years ago with a lifetime warranty unit, I am going to try to swap it out this weekend. Not sure about his theory regarding the alternator, but he has been right about a bunch of problems I have had with this car over the years.

Jack

Jack,
I'm not so sure about it being the alternator. I searched on this board on alternator threads and did not find much, if any, evidence that the alternator may cause the engine to die if the battery was otherwise charged up at the time. I would expect the voltage light to come on, the lights to dim and the engine to stay running. It would cause the lights dimming, etc, but it did not seem the alternator was killing the engine. It seems like some replaced the alternator and it did not solve the problem. The problem susequently reappeared. It did solve the no-charge situations.

I have 2 '97 Lesabres and only about a month ago I had to replace the alternator on the other one. It was failing to charge. Lights would go dim, etc, but the car would stay running (off the battery) and the lights would get dimmer and dimmer.

I found quite a few posts on bad crankshaft and camshaft position sensors. One or both of these sensors going bad can cause a similar problem. One causes a no start situation. The other can cause the engine to die intermittantly with no code. Since the sensors are located near eachother, I decided to go ahead and just replace them both. Also, these sensors are noted as a common problem area for the vehicle. I have never replaced them in this Lesabre, but I have in my other one which has a lot more miles on it. This problem has not set a code. That may be because it is so interimittant. You hit the brake, slow down and it dies. It will immediately start back up.

Other problems noted causing this were a bad ignition module or bad PCM. Without a code, it is hard to tell. Bad ignition modules seemed to cause it to die and then not restart for some time. Please let me know if the alternator fixes yours. Mine seems to be charging well at the moment and I checked the wiring and connections to it and they look good. My wife switched over to a spare vehicle, so I'll work on her Lesabre during the day today.

I replaced my crank and cam sensors yesterday and still have the intermittant dying problem. My ABS light is on. It is behaving very similar to what occurred in this thread:

http://www.automotiveforums.com/vbulletin/showthread.php?t=666852&highlight=brakes

My wife normally drives the car. I have been driving it more trying to figure out the problem. It begins to die on the down hill as the engine RPMs decrease, lights on, radio, on, etc. It has a load on the electrical. When pressing the brakes slightly, the tach drops way down or dips intermittantly. It will then die-sometimes, but not always. It seems more common when slowing from about 35 mph. The alternator gauge needle drops down to 13 volts. I think that may be a symptom of the low idling, dying problem. When it does die, the red volts light is on on the dash. Anyone have any ideas?

It may be a vacuum problem with the brakes or the throttle body. I can possibly clean the throttle body better. Thanks.

What year is this for starters?

I didnt get a chance to get the alternator swapped out this weekend, so I will have to try next weekend.

I have replaced the ECM, Crankshaft sensor, Camshaft sensor, O2 Sensor, and the TPS all in the last year while trying to figure out another problem. The intermittent dying started a few months ago.

It almost seems like a small vacuum leak in the power booster except it doesnt happen everytime you step on the brake. It is very erratic.

I am going to try and shoot some video of the tach while it is haappening to see if anyone has any ideas.

Jack

It is a '97. I will look at the throttle body closer tonight and the vacuum line to the brake power booster.

Jack, Is it similar to this problem?

http://www.automotiveforums.com/vbulletin/showthread.php?t=666852&highlight=brakes

I am going to take a closer look at the throttle body and power booster vacuum tonight. I replaced the cam and crank sensors and still have the dying problem. When I step on the brake, the tach will dip down and it will sometimes die, but not always. It does not sputter; it just quietly shuts down. Sometimes it will do it by just allowing the car to slow down without stepping on the brake. My ABS light is on and it has been on for about 4 months. I don't really think it is related to the dying though.

It is a '97. I will look at the throttle body closer tonight and the vacuum line to the brake power booster.

Sorry Smith1000 but this looks like the same issue as your other post. I believe it would be better to keep them together to cut down on the confusion factor and any possible redundant answers. :grinyes: So I have merged the two threads.

Thanks Bob, I was thinking the same thing!

Thanks Bob, I thinking the same thing!

Hi Bo,

No problem. I hate getting confused. Makes our job harder. Later.

Hey, Where'd it go? This works fine for me.

I just came in from working on the Lesabre. It seems it needs a new alternator. If I have it in drive, sitting in the driveway (emergency brake on) with the lights, radio, heater on, and I shift it into Park, the idle (rpms) will adjust with the shift and then the alternator charging drops down temporarily to less than 12 volts. The tach/idle begins to decrease. After about 6 or 7 seconds, it recovers and charges normally. It has not died while doing this (this evening).

It sounds as if the alternator has a little rattle or jingle to it. I think, at low idle, it begins to lock up, slowing the engine down. It then will recover. I think, when going down long hills, when the idle drops and the alternator slows, it catches and locks up occasionally, slowing the engine and killing it on occasion. At any rate, it definitely needs an alternator to solve the charging problem and that may solve the dying problem (it did not die this evening). I get the same volt reading at the battery and the alternator.

I checked the vacuum lines and they are good. No leaks at the power booster. I did find that the throttle body nuts were a little loose. If I sprayed carb cleaner on it, it would increase the idle slightly. I tightened 2 of the nuts, but could not get to the 3rd. I will try to tighten it tomorrow. The 2 I tightened solved the slight leak. That improved the idle, but it still has a charging problem. This likely played into the dying problem. It seems to have more than one issue going on. Thanks.

check the fuel pressure regulator. friend had one that kept dying like that. took 5 mechanics to finally decide it was the fuel pressure regulator, once that was replaced, no more problems.

had two places tell him it was the alternator. one of them even wrecked his car while they had it, what a shame, but they repaired it, and still never found that the fuel pressure regulator is what was keeping it from running

Thanks. I will check the fuel pressure regulator. I am going to check the fuel pressure again and try to monitor the pressure while getting the car to do the problem. I tend to think it is electrical related at the moment, but will check the fuel pressure again.

I can get it to do it when sitting in the driveway by shifting it from drive to park. Right after getting it in park, there is a clicking noise and then the idle (sometimes, but not always) reduces very low and then the lights will dim slightly and the alternator will read lower (less than 13 volts). It does this for only about 2 to 3 seconds and then recovers and reads/charges normally. It won't do this every time I shift from Drive to park at idle-only about every 3rd or 4th time.

When it idles low, it does not idle rough. It is a very smooth idle, just low. When driving it, I let up on the accelerator when cresting a hill, as the engine slows, the idle will decrease normally and then "dip" lower (too low) intermittantly, causing the lights to dim and the elctrical cuts out not even for a second. It recovers and then runs and charges normally.

The engine never stumbles or backfires. The idle is very smooth. When it dies, you can see the tach needle "dip" quickly (foot off the gas). If it dips low enough, it will die. It has almost died many times, but has recovered. It doesn't do this on every hill or every time I take my foot off the gas. It is interimittant. It does seem to do it more frequently when the engine is under load (lights on, radio on, air blower on full blast).

There have been no codes related to the problem. I did have a code that said misfire, plug 6, right after replacing the cam and crank sensors. Is there a switch that engages/disengages when shifting from Drive to Park? I wonder if the neutral safety switch could be involved somehow. Here are the things I will check next:

fuel pressure/fuel pressure regulator

fuel pump relay, relays and other fuses

fuel pump wiring--ground wire, etc.

throttle position sensor--maybe causing low idle? Dead spot?

idle air control valve--possibly malfunctioning--controls curb idle

The fuel pressure regulator and idle air control valve are listed as common problems for the 97 Lesabre.

Look at your list of things you're going to check. Step back and look again. Let it soak in. Think about the time you will spend. Think about the effort spent so far.

After all that I think you need to take your car to a good Buick dealer and let them diagnose it. Then decline the repair and fix it for good (hopefully). It will cost you under $100 but save you hours of frustration. How valuable is your time? Some problems can't be easily licked without the proper diagnostic equipment, which very few weekend warriors have.

Thanks. I understand what you mean. Fortunately, we have spare transportation and this is not real pressing to repair. I would like to get it fixed though. I have lots of time in the evening now that it is getting dark at 5:20.

I'll test a few items in the evening and few over the weekend and see what I can figure out.

cant wait to hear what you find. You sure have more time and patience than i do. i always buy parts and think im going to do the repairs and never have time to do them. then end up paying the mechanic to install my parts!!

I checked the IAC terminal resistance and it is fine. The reading is 59 which is in the range of 40 to 80. I noticed last night when checking some wires that the small ground cable from the battery negative terminal to the fender was very warm. Tonight, I'll check the large battery ground cable where it meets the block. It may just be a ground problem. The small wire may be carrying the ground load at times causing the charging drop. The battery terminals are good and clean as well as the smaller ground wires, but I did not previously check and clean where the large ground meets the block.

It hasn't died on me the last 3 times I have test driven it. Once the charge is going good, it will run great now. If I let it sit in the driveway at idle, full load on the battery, the battery juice eventually decreases and then, eventually, when shifting from D to Park, it will further drop the voltage to less than 12 volts momentarily and the lights will dim. The charging and rpms will them recover. It has not died when doing this; it just causes a decrease in voltage which reduces the idle slightly.

Good find on the small ground wire, it certainly shouldn't be getting warm. I believe the large ground wire connects underneath the ICM mounting bracket. Look that cable over carefully, it's possible for the wire to corrode internally.

Fuel leaking through the diaphragm of the fuel pressure regulator could cause stalling at low RPMs. Pull the vacuum line off the fuel pressure regulator and look & smell for gasoline.

I pulled the vaccum line of the fuel pressure regulator and no gas or smell of gas. It seems to have a good vacuum there.

I added a ground cable this morning. I just ran a new one from the battery top neg post to near the ac bracket. My wife drove it yesterday and it ran fine she said. It hasn't actually died for quite some time, so I believe I will see how it goes for a week or so. She is running errands in it right now.

It has been running good and did not die at all yesterday. I still notice thought that when, for instance, you back up and put it in drive, that "switching" (it sounds like an elecrical switch--it clicks and the idle changes) or change in idle or momentarily increase in load, drops the tach and volts just for an instance (sometimes, but not every time). Foot on the gas it recovers fine and goes. It is not dying now, probably because of tightening the throttle body nuts. I am not exactly sure where the clicking or switch noise comes from under the hood. I think it is part of the transmission link. There are 2 electrical connections there. Someone may know what happens in that process.

It seemed to have 2 or 3 things going on. I am still not totally sure that the issue is resolved. I might look at some of the fuses and relays today. The switching or clicking after shifting to drive or nuetral, that results in the click and then idle change may be involved, however, it is running good enough now that it is not dying. It proceeds to charge well and I have not seen the tach "dip" or drop when driving for quite some time. As long as the dying issue is resolved, we should be okay.

It still has not died for quite some time, but it did register a code today when the tach "dipped". It had a P0122. This indicates " TPS/Pedal positon sensor A circuit low input".

Does anyone know this code. Maybe it is a bad throttle position sensor?

Here is an update:
It has died a few times since I last posted. I have 2 '97 Lesabres, so I swapped out some parts to see if it would fix the problem. I swapped the ECU, ignition modules and coils, throttle pos. sensors and Idle Air control valve. This did not solve the problem. It still wants to do the same thing. I checked all of the relays by swapping them around. It still has the same problem. I pulled the fuses on the right side near the glove box. They look good. I put them back in.

I checked the fuel pressure again. It is steady at about 41 lbs. at idle. When accelerating, it increases normally. The fuel pump seems to maintain fairly good pressure. It may go as low as 40 lbs occasionally and possibly to 39 lbs at times, but when it drops to low idle and low volts, the fuel pressure looks good.

I may swap out the batteries just to make sure it is not a problem within the battery. Right after shifting to park, the lights will dim, tach will drop and then volts will drop. It usually doesn't die when not moving. It will then recover and the volts will increase.

I disconnected the EGR valve wiring and it seemed to solve the problem temporarily....but, then it returned once idling for awhile. I may run it for a few days with the wire disconnected. I checked for codes and have no codes or a check engine light. Since I disconnected the EGR valve, there is now a check engine light.

I am still looking for ideas. The main issue is the idle dropping out intermittantly. When it drops the lights flicker and and proceed to dim and the charging decreases temporarily to below 12 volts.

I have discovered the idle drop has more to do with with pressing and releasing the brake pedal than shifting it into park. I had my wife press and release the brake. There was kind of a wheezing noise coming from out of the power booster. I believe it must be leaking air or losing vaccum internally. When the pedal is pressed or released, the idle hunts. It initially will drop very low after releasing the brake pedal. The vacuum loss is resulting in the low idle. The slow idle translates into a drop in voltage.

Sounds reasonable and if the rpms gets too low your alternator will not have the proper output. Your power brake booster may have a ruptured diaphragm. Also, check the check valve and vacuum line that comes off the backside of the UIM to the booster. You could run an inexpensive diagnostic check with an automotive vacuum tester. 0-30 hg type. Good engine vacuum will be around 15 to 22 in-hg at the intake manifold.

New power booster is in and it seems to be running well now. I could not get it to idle down or dip down too low once the new booster was installed (by pressing on the brake). I think I may have it fixed this time. The brake pedal seems firmer too.

I hope somebody had a good time putting those nuts on the back of the booster in the factory. I had a heck of a time getting one of them off. There was no room and it was hard to see. My 3 year old son came out and tried to help and got us both wedged in between the seats and the dash. He kept saying, "I got a bad bolt here." I ended up just leaving the nut off of one of the bolts and I put a couple of extra nuts on the opposite side.

My brother-in-law who is a military mechanic was up and was telling me it probably wouldn't be too bad of a job to replace it. He was then looking under the hood later and saying, "Ooh, oh, hmm, this doesn't look good and I see a lot of padding under the dash." He didn't stick around very long after that. He said many of them unbolt on the engine side.

We'll just have to drive it a while and see how it goes.

I had the same problem and it took a long time to solve it. It ended up being the MAF sensor. Cleaning doesn't always solve the probelm. I had to get one from a junk yard for $25. I then had a high idle problem and that turned out to be the TPS. The stalling happens downhill becaus ethat is when the throttle is off and you are coasting. I doubt if the brakeing has anything to do with it. I've read others have had to change other sensors for similar problems, such as cps,etc, but I did not. Also, check all the vacuum hoses around the air intake, they sometimes get brittle and break or fall off.- Good luck

Thanks. I'll keep the MAF sensor in mind as an item to check should it return. It is one of the items I have not swapped out as a test. This would idle down when stepping on the brake even when sitting in the driveway. It would sometimes die when coasting. It may still do that at some point. That could still be a problem.