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So, I experienced this little fluke tonight while driving around for work in the '99 SE. Was going down a Highway in the boonies, going about 48mph. Was starting to slow down for a stop (Guessing around 30mph) I look down and the Tac is at 0 and the dash lights start to dim.

Engine stalled while moving. Didn't even notice it stall since this thing runs so smooth and quiet. Pull over, put it in park and cracked it, almost instantly fired up (Like any motor thats nice and warm) like it didn't even skip a beat.

Just got home and checked some connections, jiggled some wire looms and such while it was running. Nothing out of the ordinary.

I replaced a failed MAF about 3yrs ago. Have new Upper and Lower O2 sensors (Denso) the rest of the motor is OCD/Anal maintained. I always check stuff and make sure everythings in good standing.

SO! Was it just a fluke, or is it gonna come back for another round?

Cheers,
-Tom

Consider it a fluke until you are proven otherwise, that's how I roll. You could try pulling codes, but it would be hard to track down the issue if it isn't consistent, so you really can't do anything until it does it again.

If it starts doing it regularly then you need to make note of the conditions
every time it happens so the problem can be diagnosed.

For example: Old crank sensors will start to fail when they get hot and
cause the engine to die, often without throwing a code, but they would
rarely stall a cold engine.

Or you could have a fuel pressure regulator going out, or a weak fuel pump.

Just start making notes, it will probably do it again at some point,
because cars (like people) don't get any younger.

Indeed. Heres hoping it doesn't happen again. At least until its warmer :p

I've been meaning to change the Fuel pump and Float assembly, Mainly because the Fuel gauge acts goofy when you fill it up. Sits at Full then slowly works its way down to Empty, then goes back and forth for about 60miles. Then when it gets low enough (Little under half tank) the gauge bounces between full and 3/4 full.

BUT! I'm not looking forward to dropping the tank. Gotta get new straps, and deal with old plastic quick clip lines. GM really should have put an access panel in the floor of the rear seat/trunk to get to the fuel pump.

Anyway, we'll see what happens next.

Cheers!
-Tom

hi, I would suspect a charging issue if rpm affect light intensity..... have the battery load tested and check alt.- that's easy enough to start with

Batt and Alt are both new as of last year, I put them both in when we we're having -20 temps. The lights dimmed down because the motor wasn't running, Heat, Radio, HIDs and brakes were all on, so thats a decent draw right there.

Not a charging issue.

Tomorrow, I am replacing the crank sensor. Got a new BWD CSS20 here for $40. Not looking forward to getting the crank pulley off. Now is the crank bolt standard thread (Lefty loosy, Righty tighty) or is it bass ackwards? Hoping the Impact will break it loose, if not guess I'll do the bumping starter trick.

Well that didn't go the way I had hoped. 3 different impact (2 Air and one Electric) Crank bolt doesn't budge. Breaker bar on crank bolt, bump starter, still won't break loose. If there was a way to jam the flexplate/flywheel, I would try to break it loose that way.

So I guess I'm gonna wait on that CAS, maybe it was a fluke. Car fires up and runs great. I checked some connections and tapped on some relays.

I've never seen a crank bolt this hard to get loose. GM must have used Hillbilly torque.

From what I recall, it was 120+ft lbs, plus additional rotation to stretch the bolt, plus thread locker.

It can be fun. My PA came off with the impact gun with a bit of fight. Our old Bonneville took a prybar in the flex plate, with 24" breaker bar.

TheLoyale wrote:Well that didn't go the way I had hoped. 3 different impact (2 Air and one Electric) Crank bolt doesn't budge. Breaker bar on crank bolt, bump starter, still won't break loose. If there was a way to jam the flexplate/flywheel, I would try to break it loose that way.

So I guess I'm gonna wait on that CAS, maybe it was a fluke. Car fires up and runs great. I checked some connections and tapped on some relays.

I've never seen a crank bolt this hard to get loose. GM must have used Hillbilly torque.

FWIW, Dewalt recently came out with a brushless motor 20v cordless impact wrench with 700 ft lbs torque and 3 speeds.
Might be worth a try.

In the last year that I owned my 93 SE, the engine died a number of times when I would steer kinda' hard to change lanes or turn off the road, etc. Always re-started right away. Never did figure it out. Donated the car to a local charity and they auctioned it off, problem solved. Good luck.

Indeed, it looks like I may be buying a larger higher torque impact. One this one, there isn't much on the flex plate to grab onto with a pry bar. And I really don't want to tweak the plate if I really need to put some force on the bolt.

So the crank bolt is a stretch bolt? Is it reusable then? Although I have reused stretch bolts when doing Head gaskets.

Also, was wondering. Do these cars have any type of safety that would cut fuel/spark in the event of a sudden jolt or change of angle of the vehicle? A few winters ago, I bumped a curb at about 10mph (No damage) but the engine stalled right away then as well.

My 93 PA (H Body had this problem too) has broken baffles in the fuel tank. When the fuel starts getting low (3/8 is the typical magic point), the fuel can pull away from the fuel pickup when it all sloshes to the front of the tank, because the baffles aren't in place to retain some fuel for the fuel pump to pull up. The lower the fuel level gets, the worse it gets, to the point where I can stall on sharp maneuvers and even highway on ramps (think G-forces).

If this is the issue, you can usually confirm it pretty quickly when the fuel is getting low. Usually a stomp on the brake in at a parking lot roll pace below 1/4 tank will stall mine every time.

I have simply worked around the issue by just being aware of it, and refueling at 3/8 of a tank. My fuel gauge is also all over the place, and I think it's related to this issue, but YMMV on that point.

That is interesting insight. And since filling it, my fiancé and I haven't noticed any issue so far. I usually keep the fuel tank no lower than Half usually, but since the gauge was pegged on Full, I'm betting fuel was a bit lower than half. Perhaps if I ever get around to swapping in a new pump, I might just see about a new tank. Or live with it like you have.

Its really not a big deal, if that is the case. Another thing I might add is, this is the only car I've owned were the Pump will click off at the gas station, and I can put an extra 5gal in the tank and still not have it spew fuel all over the place.

My Landcruiser, once the pump clicks, I can barely round it up to the next dollar without gas puking out Haha.

When I did the crank sensor on mine, the harmonic balancer bolt was a major pain.
I set up a jig with extensions, some wood, a jack stand, and a five foot galvanized steel pipe.
The jack stand and wood held the socket extensions level, protruding out of the
wheel well. Then I put the five foot pipe on the breaker bar as a cheater, and stood on it.

I still had to bounce up and down on the cheater pipe many times and the bolt slowly
started to move. Oh yeah, and I torched it with a MAP torch a bunch as well.

Skregal, That is pretty much how I was thinking about going about it. How did you hold the Flywheel? I can't seem to find a way to jam it up with anything. If I could have, I would have probably got it the new CAS in.

So something new tonight. My girl drives it to work in the AM, and I sometimes take it to work at night. She said its been starting a little odd off and on (Fires up, but takes a second to come to life almost) and has been lofting a little while driving. She said it felt like she lost power, then it came back.

So tonight I took it to work to see how it reacts and what its doing. Seemed a little funky going to work off and on, At a light the RPMs dropped down to 500ish and came back up to 8 or 900. Almost like you put a serious electrical load on the motor (Alt was charging about 13.7v and is steady)

So after getting to work, I let it sit for about 3 or 4 hours. Go out to start it, Fired up, idled like crap and stalled in about 3 seconds. Fired it up again, ran like crap then came to life. Sounded almost like the Timing was off. No codes, checked when I got home. Let it idle in the drive way for about 10min, running pretty normal. Temp was hot enough to kick the fans on.

Was debating on trying to check Fuel Pressure and see if the Pump is priming quick enough and steady. Not 100% sure how to put a Pressure tester on this one though.

I am more than happy to fix whats failing, but I can't fix it if I can't narrow this down lol.

Cheers all!
-Tom

A bad oxygen sensor could cause this as well. My 96 Grand Prix had similar issues that were solved by a new one.

haro1225 wrote:A bad oxygen sensor could cause this as well. My 96 Grand Prix had similar issues that were solved by a new one.

I agree, I changed both O2 sensors during summer because of a lofting issue and stalling. Replaced both with Denso. I've never had issues with Denso anything (Japanese Car guy here) but then again, you can't rule anything out until a code pops up.

I can't remember how I held the flywheel. I think there is a small hole in it
and I stuck a screw driver through it. I could be wrong, just can't remember.
But yes, you do need to hold the flywheel with something good, not just
visegrips.

Not sure your issue is with the crank sensor, however, if you are having
issues with how it runs and how it idles.
Usually the crank sensor problem will cause a complete stall.

We did it by pulling the inspection cover off by the starter, and jamming a prybar into the teeth of the flexplate, with someone holding it to maintain leverage on the flex plate to counter the torque on the bolt. This method is absolutely a 2 person job, and requires the stronger guy to be on the bottom, and can cause problems if the bottom guy loses grip, because stuff can get stripped.

I took another look at the fly wheel. Indeed it has a hole that runs thru it. So I might be able to jam a screwdriver thru it.

I dunno if its the crank sensor either. Today, after sitting for 2 days, it started and idled fine, its also in the upper 20s (At lot colder than its been recently)

I also checked all the connections I could get to today, nothing looks out of place, all connecters are clean and such. So its a guessing game still. I don't like guessing games when its Winter, so far this winter has been extremely warm, with no snow. But then how long is that gonna last. But it wouldn't be the first time I've fixed crap in a Blizzard :p