94 LeSabre surges/dies when hot, now won't start
mojoluck
08-11-2009, 10:30 AM
94 LeSabre custom 3.8
Long and detailed problems with my 94 LeSabre:
About a year ago, she began running rough, surging and bucking on the highway at speeds over 50 (felt like a bad plug or plug wire). Then, when it was really hot outside, she began to have issues reaching 50 and would be very sluggish (she drove better in cooler weather). Plugs and wires were fine, and treatment was added to gas tank. Then one summer afternoon, after driving her about 6 miles, she kept losing speed and it felt like the throttle was doing nothing and eventually the car would not accelerate at all. After sitting until that evening, she drove fine.
Right after this occurred, the harmonic balancer went out and had to be replaced. The mechanic who replaced it said it would most likely take care of the problems (it didn't) and to replace the fuel filter (we did, with no change). As the weather cooled, she ran a bit better, but was still slow to accelerate.
Within the past four months, the surging and bucking increased. We discovered the ignition module and coil packs were bad, so the module and all three packs were replaced in April. The car ran really great for a while, then began being sluggish again (again, acting like bad plugs or plug wires). New plugs and wires were replaced several weeks ago, and no change in her performance. Regular fluid maintenance has been done as well.
Recently, the issue with the car has been that when you brake to slow down, she will act as if she is going to die. Also, if she is driven for more than 40 minutes (or less time if it is hot outside), she will surge and buck badly and then die while being driven. Usually, she will start right back up and will run again, but still with the surging (if she is allowed to sit for a bit before re-starting, she runs a bit better). When she begins to surge and buck, if you press the throttle, it feels like it is doing nothing.
Just the other day, she died after having being driven about 5 miles across town on a hot afternoon. I slowed at an intersection, she died, and has since refused to start.
My brother-in-law checked her plugs/wires and said that none of them were getting any spark at all. I had the parts store replace the ignition module, and that did not solve the issue. I have purchased a crankshaft sensor, but am unsure if that is what I need to look at next.
My question is, is the crankshaft sensor the next sensible thing to look at replacing? Can that sensor cause her to act the way she has been for such an extended period of time? Please understand that I don't know how to repair vehicles and do not have the funds to put her in the shop, so nothing has been done to check codes. (My Check Engine and Security lights have been on for past two years, after a mechanic went into my steering column to fix an ignition wire. The car ran fine for a complete year after those lights began coming on.)
Long and detailed problems with my 94 LeSabre:
About a year ago, she began running rough, surging and bucking on the highway at speeds over 50 (felt like a bad plug or plug wire). Then, when it was really hot outside, she began to have issues reaching 50 and would be very sluggish (she drove better in cooler weather). Plugs and wires were fine, and treatment was added to gas tank. Then one summer afternoon, after driving her about 6 miles, she kept losing speed and it felt like the throttle was doing nothing and eventually the car would not accelerate at all. After sitting until that evening, she drove fine.
Right after this occurred, the harmonic balancer went out and had to be replaced. The mechanic who replaced it said it would most likely take care of the problems (it didn't) and to replace the fuel filter (we did, with no change). As the weather cooled, she ran a bit better, but was still slow to accelerate.
Within the past four months, the surging and bucking increased. We discovered the ignition module and coil packs were bad, so the module and all three packs were replaced in April. The car ran really great for a while, then began being sluggish again (again, acting like bad plugs or plug wires). New plugs and wires were replaced several weeks ago, and no change in her performance. Regular fluid maintenance has been done as well.
Recently, the issue with the car has been that when you brake to slow down, she will act as if she is going to die. Also, if she is driven for more than 40 minutes (or less time if it is hot outside), she will surge and buck badly and then die while being driven. Usually, she will start right back up and will run again, but still with the surging (if she is allowed to sit for a bit before re-starting, she runs a bit better). When she begins to surge and buck, if you press the throttle, it feels like it is doing nothing.
Just the other day, she died after having being driven about 5 miles across town on a hot afternoon. I slowed at an intersection, she died, and has since refused to start.
My brother-in-law checked her plugs/wires and said that none of them were getting any spark at all. I had the parts store replace the ignition module, and that did not solve the issue. I have purchased a crankshaft sensor, but am unsure if that is what I need to look at next.
My question is, is the crankshaft sensor the next sensible thing to look at replacing? Can that sensor cause her to act the way she has been for such an extended period of time? Please understand that I don't know how to repair vehicles and do not have the funds to put her in the shop, so nothing has been done to check codes. (My Check Engine and Security lights have been on for past two years, after a mechanic went into my steering column to fix an ignition wire. The car ran fine for a complete year after those lights began coming on.)
maxwedge
08-11-2009, 12:23 PM
Lots of guess work and no diagnostics, hence the unnecessary parts. On a scanner see if you have cranking rpms, if none the crank sensor or wiring from the sensor to the ign module is the usual cause. Also test for proper fuel press. this can cause some of your symptoms also, bucking and loosing power, but the no spark issue is # 1.
mojoluck
08-12-2009, 09:18 AM
Had a friend check the Lesabre. My harmonic balancer is bad. So my question is, would a bad harmonic balancer cause all of the issues I've had, with my car dying while being driven, and now not starting at all? She turns over, but just doesn't start.
big white bufflo
08-12-2009, 07:26 PM
yes the harmonic balancer has the ring that breaks the signal for the crank sensor when you pull it of make sure you check the sensor for damage it is very close in there the sensor is located in the front of the moter behind a plactic sheild not very hard to change once you remove the balancer and not that exspencive of part
m_schroeder
08-26-2009, 07:47 AM
Just read your post, and as much as I hate being on a stump, these problems you are describing sound very close to the same problems I experianced, but much worse, with a bad 2 way check valve downstream from the vacuum line tree on the manifold and a dirty MAF sensor, located near the air intake input.
I also had a bad balancer, but that only created noise and other strange vibrations. It made no difference with the perfomance. I also replaced plug wires in the past. Spent tooooo much for that work. It did nothing for some of the problems that remained.
The MAF sensor can ruin "get up and go" or smooth acceleration in many ways. A leaky vacuum system ruins fuel delivery, cruise control, shifting, braking, causes acne, global warming.......maybe not all of those, but the engine depends on a good tight system. I was really surprised how leaky and "non-checked" the two way valve was in my car, before I replaced it. Can't go wrong with a 1/2 hour repair time on those two items.........It won' hurt.
Hope this helps....
I also had a bad balancer, but that only created noise and other strange vibrations. It made no difference with the perfomance. I also replaced plug wires in the past. Spent tooooo much for that work. It did nothing for some of the problems that remained.
The MAF sensor can ruin "get up and go" or smooth acceleration in many ways. A leaky vacuum system ruins fuel delivery, cruise control, shifting, braking, causes acne, global warming.......maybe not all of those, but the engine depends on a good tight system. I was really surprised how leaky and "non-checked" the two way valve was in my car, before I replaced it. Can't go wrong with a 1/2 hour repair time on those two items.........It won' hurt.
Hope this helps....
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