My Goldsmobile might be done...

[Ross Love]

Hi all, thanks for the help in the past,

1994 Oldsmobile Eighty Eight/ 3.8L

So a couple of months ago, my car started to shut off randomly when I was driving. It seemed to do it more when the car was warm/ had been running for a little while. After it died, it would start right back up with no hesitation. It over the course of about two weeks, this problem was off and on, doing it every other time I drove it, maybe even a little more frequent than that. From what I remember, it seems like after it did it once, it would do it again about a minute later or so, then do it again. I think I could trigger it by stepping on the pedal, but it wasn't always triggered by that.

I was putting up with this issue, while also struggling with a transmission issue for maybe two or three weeks before I parked it. I went back a week or so later and my battery was dead, and I needed to get into the trunk (key doesn't work) so I hooked up the jumper cables and popped the trunk. After a min. or two, I tried cranking it. It cranked pretty strong (I think, if I can remember) but wouldn't start. I tried again, and no start. I tried again, and all the electrics on the dash cut out, and no more cranking. Now when I hook up jumpers, there is no power anywhere. I was just about to try to pull some codes, but I had read online that a normal scanner wouldn't work for some reason, I cant remember, but i never got around to it.

Did a main fuse pop? Did I fry the computer? The car has been sitting for a month or two because I'm fed up with it, and have not had time to work on it with school running my life. Any help/ input would be much appreciated.

Thanks in advance.

[serge_saati]

You've may have 3 small differents problems, but your car is not necessary done.

For the intermittent cut off during driving, it could be either a bad electric contact on the positive remote terminal, or a bad contact in the fuel pump. Or the fuel pump is weak.

For the transmission issue, what is it? Slipping or disengage sometime?

For the dead battery, it's normal that after 2 weeks it discharges. All cars are like that.

For the no start issue, it seems to be a bad fuel pump. Check fuel pressure and pump relay. And also check the electric contact near the battery.

For the scanner, you need a special GM code to read this vehicle since it's an OBD1 system with special protocol. But you'll not have code if it's an electric or fuel pump issue.

[Ross Love]

The transmission is a whole other can of worms. It is a very weird problem. For a while, when I started the car, and tried to shift it into gear, it wouldn't go. It simply sat like it was in neutral. Then, if I shifted into first gear, it would grab, and I could shift it into drive and I could drive. This occurred for a couple months until it stopped grabbing in first, and I really had to fix it. So I went for a fluid flush at Aamco or some place, and that didn't fix it. But they didn't replace the filter. So I replaced the filter, and the tranny worked perfectly. I drove the car for approx 5 more months, then the problem came back, so I figured it was a clogged filter again. I replaced the filter again, and nothing changed. I will add that I reused the fluid that I was using before because I am a broke college student (probably not the best idea, but it looked pretty clean - don't grill me for this that stuff is very expensive).

Even if the battery is discharged, I should be able to jump it, no? When I was trying to jump it, it would crank for like 5 seconds, and not start... crank for 5 seconds, and not start... Then crank for 3 seconds and boom, all the lights in the car turned off, no power anywhere. This is odd - I had no idea what happened. To my knowledge, there is no main fuse in the car, and all of the fuses are okay. I doubt that I have a major grounding issue, because this happened halfway through trying to crank it. If I can get power to the car, I can tell if the fuel pump is priming/ fuel pressure etc. but I cant figure out what popped when I was cranking.

Thanks for the uber fast response, much appreciated.

[serge_saati]

Originally Posted by Ross Love

The transmission is a whole other can of worms. It is a very weird problem. For a while, when I started the car, and tried to shift it into gear, it wouldn't go. It simply sat like it was in neutral. Then, if I shifted into first gear, it would grab, and I could shift it into drive and I could drive.

Ok, it's not a transmission failure. I know this issue, it's very simple. It's a problem with your TRS (transmission range sensor). It's a switch that detect which gear you select. Cause modern automatic transmissions (88-today) are electronically controlled. Changed filter and fluid is totally useless.
Just replace the TRS. It costs about 90$ with the labor.
Or you can put it in 3 it will work with overdrive off.

Originally Posted by Ross Love

Even if the battery is discharged, I should be able to jump it, no? When I was trying to jump it, it would crank for like 5 seconds, and not start... crank for 5 seconds, and not start... Then crank for 3 seconds and boom, all the lights in the car turned off, no power anywhere. This is odd - I had no idea what happened. To my knowledge, there is no main fuse in the car, and all of the fuses are okay. I doubt that I have a major grounding issue, because this happened halfway through trying to crank it. If I can get power to the car, I can tell if the fuel pump is priming/ fuel pressure etc. but I cant figure out what popped when I was cranking.

Yes, I don't think it's a fuse issue. The starter doesn't pass through any fuse. It's connected to the solenoid which is connected to the battery.
Maybe the jump wires were not connected properly, so you used the juice of your own battery. Try to jump start it again, but let your car charge for at least 3 minutes before starting, otherwise you'll discharge it for nothing.
While charging, test other accessory. Check also if you've same voltage on both battery. And check if your remote positive terminal bolt (not the one of the battery) is properly tighten. The one that connect wire of battery to the fuse panel.

[Ross Love]

Okay, so I went out today and fiddled around with the fuse box power (why are there three separate places for fuses in this damn car?) and re-tightened the power/ ground on the battery. The battery is completely dead, showed 0v. I connected some jumper-cables to my moms car (good battery, I saw 10+ volts) and I got my dash lights to come on. After a couple minutes of charging, I saw ~ 7 volts on my battery.

On a side note, I recall why my battery kept dieing during the last week when I was driving my car. My fans would stay on until my battery would die. Sorry I forgot to mention this in my original post, but It has been a couple months since I have driven the car, let alone touched it. So what is the problem here? Unintentional power to ground? Bad relay? Do the fans usually stay on after the car is shut off to cool it down - and maybe my coolant temp sensor is broken?

So I tried to listen for the fuel pump priming, but I could not hear it over my noisy fans that were on. My car would crank slow, but there was not enough juice to turn over.

Thanks for the heads up on the Transmission Range Sensor. Is this sensor located on the steering column? Or tranny?

The car is currently located at my moms house 120 miles away from where I go to school, and I'm back for mothers day, so I don't have a bunch of time to work on it, but I visit quite frequently. Next time I come back, I'm going to take my battery in to get it checked, maybe recharged if possible - if not ill buy a new one. Ill rent a fuel pressure tester from a local auto parts store. Ill hopefully get some good advice on the fans so I can fix that issue as well. And I will hopefully (at this point) be able to start the car and further diagnose the shutting off problem. I hope it is the fuel pump. If I have enough time, I will replace the TRS.

Thanks for that advice, much appreciated.

[serge_saati]

10V is too waek for a boost, even if your battery is bad.
When you boost, the other car's engine should be on. So you should have 14.4V on both battery.

If you've just 7-10V, there's a weak contact on jumpers cables. maybe there's grease/dirt/rust on your terminal's connections. You should clean before placing the cables. Move the cables a bit until voltage increase.

Your fan activate after voltage drops or just after you turn off engine? Fan are controlled by the PCM (computer). When batt voltage drops, PCM is under-supplied so it activates the fan. So if the battery discharge by itself, you need a new battery.

To ear the fuel pump, hear at the middle-rear of the car, under the gas tank. The pump is there.

The TRS is on the steering column.

I'm sure you can boost your battery, but if it looses its charge after 1-3 day, you need a new one. Leaving a battery rest for many weeks is not good for battery.

[Ross Love]

My fan kicked on immediately when I attached the jumper cables. They stay on as long as the battery has a charge. You are saying that if the ECU is underpowered, it kicks the fans on? How does that work? There is no fan control module, or relay that could cause this? It would be (relatively) easy for me to go to a junk yard and pull a couple ECU's and try them out.

I poked my head under the rear of the car to listen for the fuel pump when I was out there, but I still couldn't hear it (fans are loud) maybe it isn't priming? Where is the fuel pump relay? I can check that to see if it is good.

I was also reading on this forum that a bad crank sensor can cause the car to shut off while driving? Is this another thing that I could look into/ replace?

[serge_saati]

I didn't say that your ECU is bad. The ECU activates the fan relay which activate fans.
If batt voltage is below ~10V, ECU doesn't operate properly, so it does funny thing (like activate the fan). Wait until the battery is fully charged to know if your ECU or temps sensor are bad or not.

The sound of the fuel pump is very low. It's maybe why you didn't hear it. The pump relay is in the fuse panel under-hood on passenger side (I think).

Yes, a bad CK sensor can cause the engine to turn off. It worths to check it too.

[Ross Love]

Thanks for the input, serge. Ill report back in a week or two when I have time to travel back to my car to work on it.

[Ross Love]

Small update. I got my battery charged, and put back in my car. I turned the key, and listened for the fuel pump to prime, and nothing. I started it and it idled for about 20 seconds and died. Started it again, and it took my foot on the pedal for it to stay idling, then it died 5 seconds later.

So I will be sourcing a fuel pump pretty soon. One question: where is the fuel pump access point? Under the rear seat? In the trunk?

Thanks,

Ross Love

[serge_saati]

It's located inside the fuel tank (at top).
So when you remove the fuel tank supports, you move the tank, then you open the tank metal cap at top and you remove the pump.

[Ross Love]

Okay, I was just thinking that there would be access from inside the car (that's how I have done it on my previous cars).

I will report back when I have an update. Thanks for the help.

[Ross Love]

Update

I went to the junk yard and picked up a fuel pump from a LeSabre. I didn't have enough money for a new one, so I looked for the one with the lowest miles. Also, the fuel pump 4 pin plug usually has a factory piece of plastic that you have to pull out in order to disconnect the plug, and the one on the LeSabre had a zip tie going through it, so I would venture to guess that this is was not the original fuel pump in the car.

Anyway, I put it in my car and also got a new battery. I put the new battery in and turned the key to listen for the fuel pump priming, but the fans came on again. If I am not mistaken, the fans DO have a relay for them under the hood:



So I cranked the car and it turned over. She idled a little rough, so I gave her some gas to keep the idle. I did this (a little gas) for about 30 sec. then I got out to look under the hood. Some smoke was coming off the manifolds because I think the valve cover gaskets need to be replaced, and some oil dripped down and burnt off. No big deal.

But 30 seconds later, when the car was idling on its own, it started to bog down a little, and eventually chugged to a stall. I was unable to restart the car again after this, I tried probably 4 or 5 times.

I ended up pulling the cooling fan fuse under the hood so they would stay off when I turn the key to the "Start" (or furthest before "run") positoin so I could listen for the fuel pump priming, and I could not hear it. Does the fuel pump only prime when the car is cold? Or should it always prime when the key is in the "Start" position?

On another note, my Mom says that when she owned the car, she had the ECU replaced - So I figured I could rule this out of the reason for the car both stalling, and keeping the fans on.

Any Ideas on what could be causing the car to die now?

[Ross Love]

To add onto the above post, would it be a good idea to check the fuel pump relay? Or can we now rule out the fueling?

Coilpack?
Crank position sensor?
MAF?
????

[serge_saati]

Ok, the reason why the fan turns on at start up, is either a problem with ECU like you said or the water temps sensor. But if the coolant temperature in your dashboard indicates cold, then it's a problem with ECU.

About the fuel priming, it should prime when you turn key to on, even if engine's hot. Unless if you cycle key on and off too much, it'll stop priming, cause pressure is enough high.

No, I don't think the pump relay is the cause. Cause it wouldn't cause the engine to run roughly.

I think the cause is the ECU. A bad air/fuel mix ratio control can cause the engine to run rough then finally stall. Try to replace it, and see what happens next.