2002 Lesabre randomly shuts off while driving - no codes (to cause this)

I agree about the chineese knockoff parts. Problem is, that is where your name brand AC Delco parts are manufactured. I go to pull-a-part and get a few simple parts on occasion for test purposes.

I once took got a master cylinder and vacuum booster off an old '81 nissan to put on my 78 datsun after over 4 or 5 bad rebuilds out of the box from Napa and Auto Zone. The junkyard part works like a champ. Still does.

OK- so today I went to crank the LeSabre. It would almost start but never did. I unplugged the MAF, screwed on my fuel gauge. ( thanks to GM/Buick for putting a shrader valve on the fuel rail.) Turned the ignition far enough to hear the fuel pump come on. Got out and looked at the fuel gauge. 50psi. Got in the car and tried to start it with the MAF unplugged. Same result. Unplugged every sensor on the intake. (A normal running car will start up even with the EVAP, TPS, MAF, EGR all unplugged. Same issue NO start. Plugged everything back and read the codes. Obviously I had a code for each pid I unplugged. Cleared my codes. Kept trying to start it, as it usually will finally start but run very poor. Finally started. No throttle adjustment feathering the pedal to make it rev or idle. Was able to keep it running for a minute, but running very poor as I feathered the gas pedal. Then like majic it went back to normal idle, running fine. Read the codes. None.
I have a new Crank and Cam sensor. I'm gonna replace them and see what happens. Probably do it tonight if I don't drink too much.


While I'm just your average back yard mechanic, I've been able to fix every car/truck i set my mind to fix. Got my laptop on charge upstairs so I can see a large screen of certain pids i want to monitor while it's running, but may not use it until I replace the crank and cam sensor. - still no code indicating either is defective-

If it turns out to be a clogged cat I'm gonna be angry. (Exhaust flows vey well) But I've installed test pipes before. The frustrating part is no codes. Usually if you have no electronic codes look for lean or rich fuel trims, but even that doesnt usually shut off the engine with no start.

OK gettin off track a little bit.
 
I agree about the chineese knockoff parts. Problem is, that is where your name brand AC Delco parts are manufactured. I go to pull-a-part and get a few simple parts on occasion for test purposes.

I once took got a master cylinder and vacuum booster off an old '81 nissan to put on my 78 datsun after over 4 or 5 bad rebuilds out of the box from Napa and Auto Zone. The junkyard part works like a champ. Still does.

OK- so today I went to crank the LeSabre. It would almost start but never did. I unplugged the MAF, screwed on my fuel gauge. ( thanks to GM/Buick for putting a shrader valve on the fuel rail.) Turned the ignition far enough to hear the fuel pump come on. Got out and looked at the fuel gauge. 50psi. Got in the car and tried to start it with the MAF unplugged. Same result. Unplugged every sensor on the intake. (A normal running car will start up even with the EVAP, TPS, MAF, EGR all unplugged. Same issue NO start. Plugged everything back and read the codes. Obviously I had a code for each pid I unplugged. Cleared my codes. Kept trying to start it, as it usually will finally start but run very poor. Finally started. No throttle adjustment feathering the pedal to make it rev or idle. Was able to keep it running for a minute, but running very poor as I feathered the gas pedal. Then like majic it went back to normal idle, running fine. Read the codes. None.
I have a new Crank and Cam sensor. I'm gonna replace them and see what happens. Probably do it tonight if I don't drink too much.


While I'm just your average back yard mechanic, I've been able to fix every car/truck i set my mind to fix. Got my laptop on charge upstairs so I can see a large screen of certain pids i want to monitor while it's running, but may not use it until I replace the crank and cam sensor. - still no code indicating either is defective-

If it turns out to be a clogged cat I'm gonna be angry. (Exhaust flows vey well) But I've installed test pipes before. The frustrating part is no codes. Usually if you have no electronic codes look for lean or rich fuel trims, but even that doesnt usually shut off the engine with no start.

OK gettin off track a little bit.
Please let us know how this turns out. I hope the cam and crank sensors will take care of the problem. When you remove the harmonic balancer for the crank sensor, check the gear puller arrangement. I love GM products but pulling this balancer is kind of strange especially the first time. You will be using three very long but very small diameter bolts. Either 1/4 inch or 6mm but I can not remember which it is. So watch out for this as it is easy to have serious problems with thread issues.
 
When it wouldn't start up when cranking, you should have pulled a plug wire and inserted an old spark plug and laid the plug on the manifold or engine metal for a ground. Then have someone crank while you look at the strength and color of the spark you're getting.

Air
Fuel
Spark

With all that cranking, did you get a smell of gasoline coming from the exhaust which indicates you're getting fuel into the cylinders via injectors injecting fuel into the cylinder?

You might also try feeling an injector to see if you feel the pulse. Or some folks use a marker light bulb with the two wires as the bulb contacts and plug them into the injector power connector to see if it flashes with the injector being stimulated by the computer.

I've never tried the bulb myself. Someone may have a better way to test the injectors.
Having fuel pressure on the line doesn't mean the injectors are injecting...

Good luck.
 
Noid Light is what to use for testing injectors, it will confirm that the fuel injector is receiving both power as well as the switching/pulse signals.
 
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You will be using three very long but very small diameter bolts. Either 1/4 inch or 6mm but I can not remember which it is. So watch out for this as it is easy to have serious problems with thread issues.
The bolts required are 6x80mm with thick washers behind the bolt hex nut. I also should add, you can not expect to find the proper 6mm bolts (grade 10) bolts in any of the rental big brick store loners, or the Habour Freight pullers set! Hardware stores may be the best solution for the bolts and thick washers. I keep my three 6-mm bolts & washers wrapped in glad-wrap in my puller set.
 
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I keep my three 6-mm bolts & washers wrapped in glad-wrap in my puller set.
Good idea. I have two that came with my puller. Gotta get another, or three. Looks like GM would use larger bolts. - I had to use the bump the starter trick to loosen the balancer bolt. I have a good impact gun but it didn't have the muscle to loosen the bolt.
20210710_183210.webp20210710_183210.webp
 
x2 on what HotZ28 said. I had to get the required 6mm bolts at a local hardware store. Did my first crank sensor about 15 years ago on a Bonneville or an Olds 88. Not fun but I got it done. 😀
 
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Waiting on my local hardware store to open so I can get the correct size bolts for my puller. It came with two that are the correct size but i need 3.
I'm also debating on replacing the seal. 188000 miles on this motor. If i buy a seal before taking the balancer off it may have the small groove that occurs where the rubber seal contacts the balancer shaft. Then you need the thin sleeve to put around the shaft to insure a proper seal.

Shit, i like to do things right so there's no worry about having to redo something. Probably gonna get a new seal and hope there's no groove on my balancer shaft.

I really like this car. I've replaced the headliner, AC compressor numerous maintenance items and with a wax job it'd look like showroom.

OK stores gonna open soon. I'll update as necessary with some hopefully good news. (still don't understand why no codes) 😡
 
Waiting on my local hardware store to open so I can get the correct size bolts for my puller. It came with two that are the correct size but i need 3.
I'm also debating on replacing the seal. 188000 miles on this motor. If i buy a seal before taking the balancer off it may have the small groove that occurs where the rubber seal contacts the balancer shaft. Then you need the thin sleeve to put around the shaft to insure a proper seal.

Shit, i like to do things right so there's no worry about having to redo something. Probably gonna get a new seal and hope there's no groove on my balancer shaft.

I really like this car. I've replaced the headliner, AC compressor numerous maintenance items and with a wax job it'd look like showroom.

OK stores gonna open soon. I'll update as necessary with some hopefully good news. (still don't understand why no codes) 😡
Crank sensor never threw a code but my intermittent ignition problems were solved after replacing it. That was a long time ago on my first or second big GM front driver. I was new to the platform and learned a lot from the Bonneville Club and subsequently the GM Forum.
 
Waiting on my local hardware store to open so I can get the correct size bolts for my puller. It came with two that are the correct size but i need 3.
I'm also debating on replacing the seal. 188000 miles on this motor. If i buy a seal before taking the balancer off it may have the small groove that occurs where the rubber seal contacts the balancer shaft. Then you need the thin sleeve to put around the shaft to insure a proper seal.

Shit, i like to do things right so there's no worry about having to redo something. Probably gonna get a new seal and hope there's no groove on my balancer shaft.

I really like this car. I've replaced the headliner, AC compressor numerous maintenance items and with a wax job it'd look like showroom.

OK stores gonna open soon. I'll update as necessary with some hopefully good news. (still don't understand why no codes) 😡
While the balancer is removed, it is a good time to carefully inspect the unit including the rubber ring. With 188k on the vehicle an inspection of the balancer is a good idea. It is not a high failure item in my opinion but from time to time problems occur usually with the rubber portion.
 
The bolts required are 6x80mm
I got 3, 1/4-28 x 3in bolts to use on the Balancer. While i think both would work the specs i read called for the 1/4-28 fine thread. Lowes only had 2 1/2 inch long. Too short with washers. I cant understand why GM used such small bolts to pull a balancer off. If i were more industrious I'd tap the holes out for a larger bolt. Got to get it off 1st.

Thank goodness Home Depot had the bolts in 3 inch length. My harmonic balancer puller comes with 2 1/4-28 bolts but they are 2 1/2 inches long. So I've killed half the day shopping for the correct size bolts to use with my puller.....and still don't know if the crank sensor is defective. Also replacing the cam sensor wile I'm at it.

Fingers crossed. - and my laptop is fully charged.

Below is a pic of a GM puller that looks like it would work well on the LeSabre.
 

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I got 3, 1/4-28 x 3in bolts to use on the Balancer. While i think both would work the specs i read called for the 1/4-28 fine thread. Lowes only had 2 1/2 inch long. Too short with washers. I cant understand why GM used such small bolts to pull a balancer off. If i were more industrious I'd tap the holes out for a larger bolt. Got to get it off 1st.

Thank goodness Home Depot had the bolts in 3 inch length. My harmonic balancer puller comes with 2 1/4-28 bolts but they are 2 1/2 inches long. So I've killed half the day shopping for the correct size bolts to use with my puller.....and still don't know if the crank sensor is defective. Also replacing the cam sensor wile I'm at it.

Fingers crossed. - and my laptop is fully charged.

Below is a pic of a GM puller that looks like it would work well on the LeSabre.
Cam sensor will throw a code if it is bad. Happened on my last Buick...a 2001 Lesabre Limited. Easy peasy to replace. Luckily my magnet at the end of the cam was still intact.
 
Cam sensor will throw a code if it is bad. Happened on my last Buick...a 2001 Lesabre Limited. Easy peasy to replace. Luckily my magnet at the end of the cam was still intact.
I agree the cam and or crank should set a code. I just finished installing the harmonic balancer. Put a new seal in place just for peace of mind. I still need to finish the belt and put the tire back on, hook up the battery....and see what happens.

When I removed the harmonic balancer I saw something that caused me to feel extremely good the car is gonna run like it should. I took a picture and I'll go further into detail if what I think was causing the trouble turns out to be true.
I still think I should have gotten a code, but I'll know soon enough if it's fixed.
 
I agree the cam and or crank should set a code. I just finished installing the harmonic balancer. Put a new seal in place just for peace of mind. I still need to finish the belt and put the tire back on, hook up the battery....and see what happens.

When I removed the harmonic balancer I saw something that caused me to feel extremely good the car is gonna run like it should. I took a picture and I'll go further into detail if what I think was causing the trouble turns out to be true.
I still think I should have gotten a code, but I'll know soon enough if it's fixed.
On the two or three that I've done the crank sensor never set a code. This is just my personal experience. Good luck. You'll be fine.🙂
 
I got 3, 1/4-28 x 3in bolts to use on the Balancer. While i think both would work the specs i read called for the 1/4-28 fine thread.

I have no idea where you got those specs about that? The bolt holes in the balancer are 6-mm! 1/4-28 is larger by .014 and with different threads, so will bind in the threads in less than 3/8". That may work as an alterntive, but be careful to not strip out the original 6-mm threads. Latest post sounds like you have been able to remove the balancer and found the problem. Keep us informed.
 
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When I removed the harmonic balancer I saw something that caused me to feel extremely good the car is gonna run like it should. I took a picture and I'll go further into detail if what I think was causing the trouble turns out to be true.
I still think I should have gotten a code, but I'll know soon enough if it's fixed.



I really thought I found the issue when I removed the balancer. The connector to the cam sensor was not fully fastened and fell loose from the sensor wile I was looking at the Crank sensor. I was so sure that was my problem I was tempted to reconnect it and put everything back together.20210711_164701.jpg

Disregard all the axle grease on the seal as I was tempted to reconnect everything I applied grease to the seal.

Using better judgment I replaced the seal and cleaned everything up. Replaced the crank sensor, cam sensor - making sure the clasp was fully fastened and even put a dab of silicone on it.

Well long story short the problem still persists. Will almost always crank right up. Seems to do fine until I go a block or two before it stalls at a stop or when coasting. If I'm accelerating or running fast enough to press the gas pedal it doesn't seem to happen.

Still no codes. Oh if I drive it long enough it will eventually throw a po440. I've neglected this code for many miles and still don't feel that is what's causing my stalling issue as it's been occurring since I've owned the car.

I've currently put an EGR delete spacer under the EGR valve just to see if it made a difference. It did not. This morning I removed the fuel line from the fuel rail and let it pump gas into a bucket. Flow seems excellent. Pressure hasn't been a problem, although I replaced my fuel pump and regulator as discussed above in this thread.

I have no preconceived idea anyone can point out the problem over the internet, just wanted to update what I'm doing to try and get this car back to normal. It's been a great car up until this problem.
 
I really thought I found the issue when I removed the balancer. The connector to the cam sensor was not fully fastened and fell loose from the sensor wile I was looking at the Crank sensor. I was so sure that was my problem I was tempted to reconnect it and put everything back together.View attachment 31798

Disregard all the axle grease on the seal as I was tempted to reconnect everything I applied grease to the seal.

Using better judgment I replaced the seal and cleaned everything up. Replaced the crank sensor, cam sensor - making sure the clasp was fully fastened and even put a dab of silicone on it.

Well long story short the problem still persists. Will almost always crank right up. Seems to do fine until I go a block or two before it stalls at a stop or when coasting. If I'm accelerating or running fast enough to press the gas pedal it doesn't seem to happen.

Still no codes. Oh if I drive it long enough it will eventually throw a po440. I've neglected this code for many miles and still don't feel that is what's causing my stalling issue as it's been occurring since I've owned the car.

I've currently put an EGR delete spacer under the EGR valve just to see if it made a difference. It did not. This morning I removed the fuel line from the fuel rail and let it pump gas into a bucket. Flow seems excellent. Pressure hasn't been a problem, although I replaced my fuel pump and regulator as discussed above in this thread.

I have no preconceived idea anyone can point out the problem over the internet, just wanted to update what I'm doing to try and get this car back to normal. It's been a great car up until this problem.
Thanks for the detailed description and picture. In real life, things may be different but the wiring harness above the crank looks pretty rough. It looks like coolant was leaking from the water pump onto the wiring. Perhaps you took a careful look at this already.
 
Just came in from another test drive. Had my laptop hooked up that has a dashboard and allows for real time pid reading. Unfortunately the car didnt mis a beat and I could not duplicate the problem. Nothing seemed out of whak with the live readings. Battery in laptop started to get too low to keep the screen on after about 30 min.

No code is set or pending.

I may drive it around with the laptop using an inverter so I can go as long as necessary.
 
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