Need help diagnosing problem

[4Cornered]

I have a 1984 GL which is doing something strange. In the last two days, the car has stopped running 3 times. Each time, after sitting for a couple of hours it starts. On the first case, I had driven about a 1/2 mile after starting the car in a 52 degree garage. I had to leave the car by the side of the road for a couple of hours in roughly 35 degree weather. It then started right up and ran for about 1/4 mile. I towed it home, dumped in a container of Heet (thought the problem might be condensation in the gas) and it sat outside for a couple of more hours. It then started right up and I drove it into the garage and it ran fine for about 20 minutes. I shut it down since I couldn't see anything wrong. The next morning, it started promptly and I drove it a couple of miles to an appointment. It sat in 35 degree weather for an hour. It started fine, I went about a 1/4 mile to the NAPA to purchase more Heet for future use. Started fine after a roughly 10 minute wait. Drove 1/4 mile and filled tank with gas. Started fine. Drove about 1/4 mile, stopped running. Walked home and returned roughly 5 hours latter to tow. Started right up and my wife drove it home and into the garage. I've checked the primary and secondary resistence on the ignition coil, both within spec. I noticed that the voltmeter on the dash was showing a red light when I tried to start it after the 3rd failure. The battery is fine and the engine cranks with plenty of speed when trying to start. The reason I checked the coil is I think (but don't know for sure) that the tach dropped to zero just before it stopped running the last time.

Since winter here in southwest Montana can be dangerous if your vehicle stops running between settlements, I need to figure out what is wrong.

Any help would be appreciated, possibly life-saving.

 

Car details: Non Turbo, 4-speed Trans, Dual Range, station wagon, mileage: 78890, purchased from father in law, who bought it new. Original, execpt for replacement battery, tires, wipers and such wear parts. Car is in regular use.

 

Put in the new module, car worked fine during 20 mile test drive. Starts fine, no tach abnomalities. Thanks for all of the help. Have some other stuff to do with the car coming up, will probably ask more questions. While working on the car, was once again impressed with the quality of the parts, 3 wingnuts on the air clean with neoprene washers. Contrast that with the plastic snaps on my other car, and suspect that there will be a difference in lifespan.

Edited January 31, 2012 by 4Cornered
Problem Solved

[nipper]

This sounds like on first thought that either the spark amplifier or the module in the disty is going. When I had one of these it drove me completly nuts as it was dying, but the same symptons.

 

 

Look there, as that would also kill the tach, since as far as the car is concenred it can't tell the disty is rotating. My bet is on the module in the disty since you loose the tach.

 

With mine it needed a disty too, so it was pricey at the time.

[Indrid cold]

+ on the distributor replacement....

 

sounds alot like what my 84 Brat did. The ignition module in the distributor cuts in and out. Cheaper to buy a rebuilt distributor than to just buy a ignition module. I also replaced the coil too as they were both about the same age.

 

I understand the weather concerns as I used to live in SouthEastern Idaho. I always assured winter blankets etc. in bag behind seat.

Edited January 27, 2012 by Indrid cold

[AKghandi]

i would check the fuel pump/filter also. before you start buying parts that are that expensive.

[nipper]

Nahhh though never hurts to change the fuel filter. They key here is failure of the tach to work. The tach gets it signal from the primary ignition system. Without that no tach no spark no start.

 

NOw if it failed in the summer only while sitting in the sun then I would look at the fuel pump relay.

[4Cornered]

Thanks for the suggestions. I'll dig into those today. I replaced the fuel filter this fall when I did the pre-winter maintainence. Bozeman is not too far, and Subarus are one of the most popular brands so I should be able to get parts, albeit, not cheaply.

 

Since I lived in Fairbanks for a fair part of my life, I have winter gear in all vehicles.

[man on the moon]

Check the ECU for codes (search the forum), but another + for the disty. Went through almost identical events last spring a week or three after I broke the driver side timing belt. Car would start, stall, and start seemingly randomly, and with a strange combination of ECU codes. The belt had caused similar symptoms and codes, albeit only once (and with no re-start later). Eventually figured it out, replaced the disty, and no more problems

Edited January 27, 2012 by man on the moon
because it needed it

[naru]

Don`t throw parts at it.

 

Next time it quits,note wether the tach shows any rpm while cranking.

If not,you have power/coil or ignition module problems.

If yes,check for spark at the coil and plug wires.

 

Check that the fuel level is at the middle of the carb sight glass(love those).Kinda trickey-might need a mirror.

 

Thirdly,It is fairly rare ,but,I would check for carb icing.I`ve seen it w/disturbed carb heat stoves.Moisture in the air freezes into an ice cube in the carb throat.Probably not your problem,but,easy to check.

Pop off the air cleaner top and look for an ice cube in the carb throat quickly after stalling.

 

Does it sputter to a stop or die quietly?

[Cyfun]

Might not hurt to check the battery terminal connections and grounds. I always have electrical issues when the temperature drops and everything thermally contracts. Normally, if the battery terminals were corroded or werent making good contact to the connectors, the car would still run off the alternator. But if there were a problem just upstream from that, killing or weakening the flow, that could cause it to stall. Could also be fuel pump wiring, too. I once had a loose connector for a fuel pump fuse, would get worse in the winter.

 

Although the other folks are probably right about the dizzy and ignition system. Whether the tach moves or not is the key.

[4Cornered]

Opened distrbutor, pulled reluctor, disconnected and pulled pickup coil/ignition module. Can get a replacement for about $60. Going to make leap of faith and get replacement. I'm pretty sure the tach wasn't showing any RPM's when I tried to restart after stopped. When failure occured, no noise associated with event; in fact, no misfiring, just complete combustion cut-off.

Using car and waiting for another failure is not something I want to pursue. Last time, my poor balding head got sand blasted by pellet snow and 30 mph winds during the three mile walk home.

 

However, I am curious about why an electronic component should fail, then operate, fail, operate, repeatedly? In the first instance, the car wasn't stored in real cold conditions and didn't run long enough for heat to be a factor. The it sat exposed to wind and roughly 35 degrees for a couple of hours. Could there be a reset? After the third failure, I pulled the battery cable of the post, waited a few minutes, and reconnected. No change. Car cranks vigorously thoughout the whole episode.

[4Cornered]

Funny you should mention carb icing. Back in the 70's I had a Subaru in Fairbanks that formed enough carb ice to jam the carb wide open while driving. Was a scary few moments there with the car didn't slow down when the accelerator wasn't being pressed. Took some icy corners way faster than I wanted. Then Subaru sent out a TSB to install a little plastic shield to slow the airflow past the carb. My current car has one just like it.

[nipper]

Easy.

 

Parts get old and brittle, solder joints start to fail. Add engine vibration and heat you have a loose connection.

 

When the parts get hot, metal expands and can develop a poor or open connection. Things cool down (and it has more to do with compnonet heat then anegine heat and all workd again.

 

 

 

This is why electronic failures that are intermittent can drive one bonkers.