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  3. 90 Bonneville 3.8l - car runs, stalls, then cranks and won't start - no codes generated either!

90 Bonneville 3.8l - car runs, stalls, then cranks and won't start - no codes generated either!

This sort of sounds like the same thing that happened to my mother's 90 Pontiac Bonneville - same 3.8 engine as in my 89 Olds. This just started happening last week - it was running fine, I filed it with gas, then went out of town in another car.

She drove it to work with no problems, then on the way home it stalled at a light. She was able to restart it and drive a couple of miles, then at a light it stalled again. It would crank but not start. She had to be towed home. A few days later, it started again for me and I drove it a couple of miles at night.

The next day I started it up and drove it about 10 miles. It stalled at a light, then started up again. I got it over to a Ford dealer to pick up some parts for another car, then it wouldn't start for the drive home. The towtruck operator thought it might be the fuel pump.

The next day, I started up the car and it ran for about 20 minutes and then stalled. It started right up then died in 10 minutes. I let it cool off a bit, then gigled with the throttle linkage, then it started up again. SO I was wondering if this was the Throttle Position Sensor?

The car is leaking oil from the valve cover gaskets, and I plan to replace those. I doubt the car has been tuned in years, but the plugs are Autolite Platinums (not OE). I shorted the diagnostic plug and checked for any saved codes, but there were none.

SO I wonderer how the Crankshaft Sensor could be at fault if there were no codes generated? Could it be the fuel pump dying, or the fuel filter being clogged? I was gonna try and replace the fuel filter, but it is really rusted on the lines, and I don't have the proper wrenches to break the filter free from the lines.

Could this even be a bad alternator or battery?

I had thought maybe the coil pack would be at fault - so I bought a new coil, wires and plugs, and am gonna replace them since any garage I take it to would do that anyway.

Any suggestions?

Chris

Jwlz wrote:

Just an update. As I said, the crankshaft sensor was replaced and the > car died as soon as they started it up. Well, after some further > research on the I-net, I asked them to check out the Ignition > Relay/Module. They found that to be faulty and replaced the Ignition > Module. We drove the car all weekend and it seems to be doing great > now! Woohoo! No stalls or trouble starting the car at all anymore. > So, I?m not sure if it needed BOTH the crankshaft sensor and the > ignition... but after having them both replaced, it seems to be fixed > now. > > Jwlz
Reply to
USENET READER
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Because there ISN'T a code for that:

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The crank sensor is not used to tweak the emmissions output like a cam sensor, or oxygen sensor. The engine doesn't even know it's turning without the crank sensor....How would it know there is a problem if it doesn't even know it's turning? It wouldn't.

GW

Reply to
Geoff Welsh

Reply to
USENET READER

Thermally intermittent components have been a curse to many repair industries. With smaller electronics such as television sets, a chiller spray (aerosol can with an aiming tube) is used to abruptly cool a suspect component; it's amazing to see a berserk television snap into proper operation when you've hit the right part.

This, of course, wouldn't be practical on a car engine, especially if the component is buried like the crank sensor is.

Many times, a thermal problem can be the worst to troubleshoot, because a part won't test as bad under convenient circumstances.

Reply to
Robert Barr

OK - new chapter - tuned the engine (new AC-Delco RapiFire plugs, properly gapped; new wires and coil pack, and also replaced valve cover gaskets because oil was leaking all over the block).

Car was tough to start up, but once it did, it ran for 45 minutes, then stalled. Restarted fine, and didn't stall again. I killed engine, then restarted no problem.

Took car into Sears for battery and charging/starting system test. On the way over, the car stalled again, but started right up. No "check engine light" during running. Sears diagnosed a weak battery (one that wouldn't hold a charge on the rapid charger), installed new DieHard battery, did rest of the charging/starting system check - car passed with flying colors. A Sears mechanic thought that the engine might be stalling after it got hot because of the ignition module - right under the coil pack. Anyone know about that?

Took car home - ran fine. Got it home and left running for a while - engine started surging, then the "check engine light" came on while engine was running. Read code - 13 - for open O2 sensor circuit - both Chilton and Haynes books recommend replacing O2 sensor. I disconnected the battery, disconnected and reconnected the O2 sensor plug on the firewall, car ran OK for a while, then the "check engine light" came on

- same 13 code. Car didn't stall, but it seemed to want to run the RPMs down low enough so that it almost stalled.

Now why do you suppose the car didn't show codes before or after the tune up, and now it does after I replaced the battery?

Robert Barr wrote:

Reply to
USENET READER

That's just coincidence. The car is 14 years old, everything will break eventually. I am surprised it didn't have Oxygen Sensor problems five years ago.

As to the stalling, if you are inclined to spend the money, ignition modules do fail intermittantly. I can't remember, were you one of the people that already replaced the Crankshaft Position Sensor? Those are intermittant with age too.

It's also quite likely your real overall problem is a loose connection somewhere or a chafed wire. Cars that old can get difficult to work on. We are instigating a policy at work now that 1990 is our cut-off for how old a vehicle we will diagnose for drivability, unless the customer is a long-time one. GW

Reply to
Geoff Welsh

Well I really don't want to just throw parts at this car. I don't want to just go out and buy a new ignition senson or go through the aggravation of doing a crankshaft sensor (because I will have to take it into a shop to pull the harmonic balancer to replace the crank sensor per the Haynes and Chiltons books) and I don't want to through a bunch of money at the car and not have it run. I did that with an 82 Chevy and wasted close to $200 on the car and it never ran again.

Short of taking it to a Precision Tune for diagnostic work, does anyone have anything relevant to say other than just "parts wear out" and "throw more money at it"?

Geoff Welsh wrote:

Reply to
USENET READER

It ended up being the crank sensor, and the wheel it gets readings from under the Harmonic Balancer was a little hinky, but didn't replace it. The car runs great, so thanks for all your help that was on topic. It was appreciated.

Reply to
USENET READER

My boss and I diagnosed a 1988 3.8 sfi LeSabre, with stalling, poor driveability, surging problems, as having a bad ignition module. Owner bought a salvage yard unit, and had same problem. We installed new unit, problem solved.

Reply to
Mark Keeling

I ended up replacing the crankshaft sensor and it works fine.

Thanks for every> USENET READER wrote:

Reply to
USENET READER

\ Glad to see. I follow these since I also have a '90 Bonneville. Only

37,000 on it now, but it's still aging like everything else.

Did you change the part yourself? I recall you needed a shop to pull the damper. The manual recommends some special alignment tool for the crank sensor -- I've always wondered if that's necessary.

Reply to
Robert Barr

For the crank sensors that I have replaced, I've either used a matchbook cover, or a business card to align it. Never had a problem with it hitting.

Bill

Reply to
William F. Yehle II

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