90 Lesabre won't start when warm

[rl0gin]

Hey everyone, I have a 90 Buick Lesabre that I'm having trouble with.. I was hoping someone might be able to help.. For the past couple of months, my car would occasionally die when I come to a stop. I could always just restart it and then take off again. Well all of the sudden, when I would get my car warm, if I shut it off, it won't start again. It has to cool for 1-2 hours before it will start. I took my coil pack and ICM in to get tested, and the coil pack tested bad, so I replaced it. But the ICM tested good.. They tested it about 6 times because I told them it only does this when the car is warm. Every time the tests came back good. When I got home, I put the ICM back in with the new coil pack. I went to drive it, and all of the sudden while I was driving down the road, it just died. It wouldn't start again until I let it cool for a couple hours. Now every time the car just barely gets warm, if I shut it off, it won't start. Anyone have an idea as to what might be causing my problem?

PS.. Sorry for the lengthy post. I'm just trying to describe everything the best I can. Thanks.

[formzy]

Sounds like you may have a bad crankshaft position sensor. Very common failure on the 3.8L. My girlfriend's '97 did the same exact thing as yours. I replaced the ignition module but it would still just quit. Hers would re-start usually right away. I own a '90 with 107,000 miles and have not experienced this yet. It's easier to replace (less to remove etc.) on the '90, and if you know a general car guy or mechanic he may be able to do this for you. The part is cheap, but you may need to borrow a special tool to align the sensor. I think this is the area to concentrate on. Hope this helps. Sincerely, Formzy

[rl0gin]

Hey, a friend of mine that's a mechanic said it really sounds like the cam sensor.. I was gonna go ahead and change this out myself. I bought a Haynes manual but it just basically says unbolt the old one and put the new one in. Is it really this simple? Is there anything special I should know to change this out?

[buickmastermind]

nope. it's just that simple...unless the magnet inside came loose.

It won't be the crank sensor, because that is only used when the car first starts. After it's running, it is ignored.

[rl0gin]

Well, it's not the cam sensor. I changed it out, and it does the exact same thing. Does anyone have an idea of what my problem might be? When we had the hood open, my dad was washing the car and accidentally got the passenger side part of the engine wet.. After this happened, the car would start, I guess because the water cools something off and it works again. Any idea what this might mean?

[buickmastermind]

The cam sensor has two parts to it. The sensor on the outside of the motor, and a magnet under the timing chain cover. The magnet is likely broken off, as the car will start cold on a bad cam sensor, but as soon as it's warmed up it won't for "safety" reasons(?).

[rl0gin]

How do you go about changing the magnet? I bought a Haynes manual for it, but I don't see anything about it. I actually didn't know there was a magnet in there. Is it common for these things to just break off?