1989 Engine shut off while driving... what can cause this?

This week ... three times... While driving down the road ( 65mph) no traffic....for no reason the engine stalled out after about an hour..... I coasted in neutral turned the key to restart , shifted back into drive and kept driving.... This has never happened before... until three times this week .... and don't know what is causing it. I was thinking ingnition coil or some sensor but it starts right back up without any wait time..?? I brought it to the dealer and they can't find anything wrong with it....... I hate to wait for it to stop for good on the road ( who knows where) and pay for a wrecker if I can figure it out now. Thanks for any clues or suggestions.

Does the car stumble or sputter when it dies or is it immediate, as if ignition were shut off?

What do the speedometer and engine temp gauges report after it dies but before you restart it.

Symptoms do not conform to a thermal failure of one of the holy trinity, but seem more like an electrical failure of the ECM or related circuits.

An intermittent like this is a real bear to troubleshoot. Suggest wire wiggling and module tap tests if an electrical problem is the most suspect cause.

Any chance you have a spare ECM on hand?

Have you checked for loose battery cable connections or bad grounds under the hood?

Does the car stumble or sputter when it dies or is it immediate, as if ignition were shut off? What do the speedometer and engine temp gauges report after it dies but before you restart it. Symptoms do not conform to a thermal failure of one of the holy trinity, but seem more like an electrical failure of the ECM or related circuits. An intermittent like this is a real bear to troubleshoot. Suggest wire wiggling and module tap tests if an electrical problem is the most suspect cause. Any chance you have a spare ECM on hand?

When I owned a Reatta, I had the same thing happen. It occurred after I had the Harmonic Balancer replaced. When the repair was done, the Crankshaft Sensor was damaged during the replacement. My symptoms were the same as yours. The car would shut down at highway speeds. At first, it would start again, but after a few episodes the vehicle would not restart. It took a long time for the problem to be located, but once the sensor was replaced I was good to go. Yet a few weeks later, the same thing happened. It seems that one of the vanes on the HB, was very slightly bent causing it to rub on the sensor. With the HB replaced a second time as well as the Crankshaft Sensor, my problem was solved.

here's the grounds to check for looseness/corrosion: http://reattaowner.com/roj/component/content/article/62-electrical-system/other-electrical/224-ground-terminals-junction-box-location

i also had a bad crankshaft (harmonic) balancer and crank sensor that did the "intermittent" problem before it finally gave up on the side of the road.:mad: if the balancer has any cracks in the rubber (front or back), you'll need a new one and replace the crank sensor at the same time. this will not "throw a code".

speaking of codes, have you checked for any?

another cause may be the Ignition Control Module. it is located under the coil pack. if there is any green or gray "goo", you'll need to replace it.

possible but doubtful, is the fuel pump is on its last leg. (mine went out soon after i replaced the crankshaft balancer/sensor) here's info on checking the pressure: http://reattaowner.com/roj/component/content/article/67-engine-a-drivetrain/fuel-system/288-fuel-pressure-testing

i hope this helps.

When I owned a Reatta, I had the same thing happen. It occurred after I had the Harmonic Balancer replaced. When the repair was done, the Crankshaft Sensor was damaged during the replacement. My symptoms were the same as yours. The car would shut down at highway speeds. At first, it would start again, but after a few episodes the vehicle would not restart. It took a long time for the problem to be located, but once the sensor was replaced I was good to go. Yet a few weeks later, the same thing happened. It seems that one of the vanes on the HB, was very slightly bent causing it to rub on the sensor. With the HB replaced a second time as well as the Crankshaft Sensor, my problem was solved.

That is very likely your problem. It is the MAF (manifold airflow) sensor, and is one of the holy trinity that will kill the engine and not leave a code.

Very telling are the 3 wires going into the connector. They are not stock, have been worked on. They alone may be the problem, or the sensor may be going as well.

I would pull back on the wrap around those wires and verify the connections to the harness wires. A bad connection on one of them could be all that's wrong.

Tapping on the sensor while the engine is running at warm idle and listening for a hitch.

That is very likely your problem. It is the MAF (manifold airflow) sensor, and is one of the holy trinity that will kill the engine and not leave a code.

Very telling are the 3 wires going into the connector. They are not stock, have been worked on. They alone may be the problem, or the sensor may be going as well.

I would pull back on the wrap around those wires and verify the connections to the harness wires. A bad connection on one of them could be all that's wrong.

Tapping on the sensor while the engine is running at warm idle and listening for a hitch.

Thanks! That is my suspicion... now that someone concurs I will check it out.

i'm not complainin', but if we had seen that pic earlier, i think we all would have said to check that out first!

i hope the MAF wiring is it. while you are there, i'd suggest cleaning the MAF with something like "CRC Mass Air Flow Sensor Cleaner". available at most FLAPS.

good luck!

I see you have both a '89 Riv and a Reatta. All the parts talked about are the same on both cars.......so you do have spares.

OK all... THANKS for your help on this issue...., I went to the yard today and replaced the MAF with one off a 1990 Olds....going out later on so I will see if all runs well on the road..... from what I see most all the MAFs from 1988-1993 are the same?? what if I installed a different year than 1989 any issues that will happen?

the one that I installed is part # AFH50M-02E

Not the stock part #, but difference is probably minor, and ECM will probably self correct to keep mixture correct in closed loop operation. Should be close enough to verify old MAF was problem.

Not the stock part #, but difference is probably minor, and ECM will probably self correct to keep mixture correct in closed loop operation. Should be close enough to verify old MAF was problem. [ATTACH=CONFIG]262655[/ATTACH]

OK, started up and ran OK until I stepped on the throttle and it hesitated and surged.... as long as I don't floor it it seems to run fine...the MAF may look the same and fit the same but the part # does make a difference..... I will look for a correct part number AFH50M-02A... In the meantime I will not drive so I don't cause another issue. Thanks for the reference chart Mc_Reatta and everyone's help.

DO you think this is part of the issue? Looks like it is possibly leaking around the edges and I see residue underneath it.

The Crankshaft Sensor can not be seen. It's buried under the Harmonic Balancer. If you are referring to green goo leaking out of the Ignition Module, anytime this part starts leaking, it's time to replace it. While I can't say that's the cause of your problem, if this item is leaking, it needs to be replaced. That might just fix your issue.

Howard, I agree. My 90 coupe had this issue a time or two before the crank pos sensor crapped out on me. I actually found the sensor was hanging slightly loose on its bracket and would move from time to time. I didn't find it that time consuming or difficult to remove the harmonic balancer and check it, and chances are it is dirty as heck anyway. I've never seen a 3.8 with the original crank position sensor really clean.

OK, started up and ran OK until I stepped on the throttle and it hesitated and surged.... as long as I don't floor it it seems to run fine...the MAF may look the same and fit the same but the part # does make a difference..... I will look for a correct part number AFH50M-02A... In the meantime I will not drive so I don't cause another issue. Thanks for the reference chart Mc_Reatta and everyone's help.

Did you take a look in the diagnostics to see if the replacement MAF sensor is actually working? The engine will start and run with the MAF disconnected completely but responsiveness will be poor. I have used several different part numbers from the '88-'90 vin C range and have had little issue with the calibration. I have never seen a MAF sensor that looked like the original one in the photo? Maybe an aftermarket copy?

Howard, I agree. My 90 coupe had this issue a time or two before the crank pos sensor crapped out on me. I actually found the sensor was hanging slightly loose on its bracket and would move from time to time. I didn't find it that time consuming or difficult to remove the harmonic balancer and check it, and chances are it is dirty as heck anyway. I've never seen a 3.8 with the original crank position sensor really clean.

I had the same symptoms on an '84 Renault Alliance and all I had to do was clean off the the crank sensor. This would last for quite a while but eventually I had to replace it to finally solve the problem.

Cleanliness doesn't have any ill effect on the crank sensor; it's a Hall effect sensor.

DANG! It happened again while driving down the road at about 50mph.. this time did not restart right away but did after about 2 mins....returned home without issue. Today drove around and returned home fine ... then about an hour later it would not turn over... ( checked engine and it was hot) waited about another 2 hours and started up fine... maybe a temperature sensor?? this is becoming a confidence killer to drive to work or anywhere I except to arrive and return home...By the Way... Not that I think it matters BUT I am talking about my 1989 Riviera here the Reatta has been sold :-(.....HELP...

Not a temp sensor. A bad temp sensor would make the engine run rich or lean, but not stop. Could it be a possible bad ignition coil module?

As I have been doing some research... I am thinking that since I replaced the MAF Sensor...maybe its either the ICM or Crank Sensor mounted behind the harmonic balancer. Do to the heat maybe being a factor I may start looking at the ICM first....OK I checked it out and I don't see any green or any oose or fluid from the outside so I will bypass this option for now and replace the crank sensor first...

here's the grounds to check for looseness/corrosion: http://reattaowner.com/roj/component/content/article/62-electrical-system/other-electrical/224-ground-terminals-junction-box-location i also had a bad crankshaft (harmonic) balancer and crank sensor that did the "intermittent" problem before it finally gave up on the side of the road.:mad: if the balancer has any cracks in the rubber (front or back), you'll need a new one and replace the crank sensor at the same time. this will not "throw a code". i hope this helps.

I had the same problem with my 90. removed the harmomic balancer and crank sensor. The HB looked perfectly fine. I borrowed the special tool from my local GM dealer and when i tried to turn it on the HB it would hit the fins. Installed new one c/w sensor, set it with the special tool and now the car runs great.

Heat related failure makes me think it is the ICM. Even without the green ooze evident, full operating temperature is often the trigger that causes a sudden ICM failure and shutdown. That it will restart normally after cooling off again is another indication of the ICM being the issue (cooling of module results in open circuit resolving itself). Moreover, the Magnavox ICM used on 88-90 cars seems much more prone to thermal failures after many years of service than the later Delco used in 91.

If the car has high miles, I wouldn't hesitate to do the balancer and the crank pos sensor just for good measure, but don't be surprised if that doesn't solve the problem. Usually the sensor fails due to physical damage caused by the interruptor vanes on the balancer clipping the sensor. If this happens, it is a non-recoverable failure and requires replacement of the sensor (and alignment of vanes or outright replacement of HB) to get the car running again. Intemittent failures of the sensor are possible, but less likely than an ICM fault.

KDirk

Maybe the problem is with your ignition switch. I've heard that GM had some problems with those!

WOW! OK I replaced the MAF and wires worked fine ... then again began to cut off... OK... New harmonic balances and Crank Sensor... ran smoother lasted a few days then again cut off while driving again..... I have looked at the ICM and see no leakage or oozes but could this be the next step or could it be maybe the ignition in the column?

The Reatta diagnostic panel has a "snapshot" mode. It allows taking a set of sensor readings at a specific point in time and it you select when it is stumbling and then record the readings something may be evident. I have connections for my OTC2000 that allows connection to a PC and takes a snapshot evey few seconds but that setup is rather involved.

BTW when it happens does the tach jump ?

Jiggle the ignition key; lightly tap on the ignition switch while driving, and see if the problem recurs.

Jiggle the ignition key; lightly tap on the ignition switch while driving, and see if the problem recurs.

About the only way to find out what is causing the engine to stop running is to troubleshoot it when it will not run. Although it is good to look at the ICM for green/gray goo coming out, it isn't a way of determining the ignition system is working properly. First thing to do when the engine dies is to see if it is getting spark to the plugs when it won't start. That will tell you if you need to be looking for an ignition problem or a fuel delivery problem.

I have to echo Ronnies advice here. When it dies again, be prepared (with needed tools and test gear) to check for spark while the problem is still extant. If you have no spark, I am going to reiterate the likelyhood of a failing ICM.

Problem is that a visual inspection without the presence of the green slime doesn't rule out an internal failure (thermally induced or otherwise) of the ICM. Conversely, finding the green goo oozing from the module pretty well guarantees it is bad as that is the material that aids in heat-sinking and potting the internal electronics of the ICM. Once it starts melting and escaping the module's enclosure, it will fail in short order.

And again I stress that since you have stated the failure is self-correcting after the engine has cooled off, it is almost certainly a thermally induced problem and the most common point of failure in that mode is the ICM.

KDirk