posted
While driving to work this morning, my car suddenly died, and I managed to pull off onto the shoulder. I tried restarting it, but it just cranked and cranked and never started. Luckily someone picked me up and dropped me off at work (serendipitously, he was on his way to the retail store at my work).
Here's some background. The car has been giving a service engine soon light occasionally, and the trouble code it gives is 43 (knock sensor). It's been idling a little low and rough, but that's about it. But the other day, Ruth drove the car somewhere and then couldn't get it to start again. We went back to retrieve the car later, and it started up just fine.
This morning, though, it died while doing about 60 mph on the freeway, so obviously it's not the starter or battery. I'm thinking it's probably the fuel pump or a clogged fuel filter. Does that seem to fit the symptoms? Anyone have any other ideas or advice?
Posts: 9945 | Registered: Sep 2002
| IP: Logged |
posted
Nothing funky happened with the power to the dash flickering just before the car died, did it?
Posts: 16059 | Registered: Aug 2000
| IP: Logged |
posted
Nope. The engine just suddenly cut out. I didn't lose power steering or brakes or anything electrical. The needle on the tachometer just dropped to zero and I started slowing down.
Posts: 9945 | Registered: Sep 2002
| IP: Logged |
posted
What kind car? how new? My son's car did that when it was a ignition computer module of some sort
Posts: 9538 | Registered: Aug 2003
| IP: Logged |
posted
Sorry, I'm a little scatter-brained this morning and forgot that. It's a 1993 Oldsmobile Cutlass Supreme with the 3.1L V6 engine and about 148,000 miles (though I don't know if that's relevant at all).
Posts: 9945 | Registered: Sep 2002
| IP: Logged |
posted
It looked fine—I think it was still under 200. I put my hand on the radiator cap, and it wasn't even very warm yet. We hadn't even been driving for ten minutes, I think.
Posts: 9945 | Registered: Sep 2002
| IP: Logged |
posted
If it was fuel, you'd probably have an issue with sluggishness up until it cut out. I had a car a couple years ago that had a clogged fuel system, and it wouldn't just stall, it would chug a bit first.
posted
When you turn the key to the ON position (not starting yet) do you hear a low hum from the fuel tank?
Posts: 4753 | Registered: May 2002
| IP: Logged |
posted
No, I didn't. But when it wouldn't start the other day, I listened for the fuel pump and didn't hear it then, either, but it still started up. I definitely hear it in our other car, though, which is the same year and built on the same platform.
Posts: 9945 | Registered: Sep 2002
| IP: Logged |
Fuel delivery may be the problem. I wish I could just sit in the driver's seat and try turning it over myself.
Posts: 4753 | Registered: May 2002
| IP: Logged |
posted
It's got about half a tank in it right now, so that shouldn't be the problem. And I know what you mean. It's so hard to diagnose car problems when you're not there and can't see or hear what's going on.
Posts: 9945 | Registered: Sep 2002
| IP: Logged |
posted
But if it is already telling you it's receiving an error code from the knock sensor, couldn't that be a warning that something else is amiss (causing the aforementioned knock)?
quote: If your knock sensor wasn't operating properly, so that it was always indicating a knock, the engine computer's response may have been to change the ignition timing on your engine.
posted
My best guess is that the knock sensor is picking up the vibration from the rough idle and interpreting it as a knock. I've never heard it knock, though, and the service engine soon light only comes on after it starts idling rough. So I don't think that it's that serious.
Posts: 9945 | Registered: Sep 2002
| IP: Logged |
posted
I read the codes myself. It's an OBD I computer, so I can enter the diagnostic mode and display the codes on the dash by jumping the terminals on the code scanning port with a bent paperclip (I keep one handy in the center console). There weren't any new codes.
Posts: 9945 | Registered: Sep 2002
| IP: Logged |
quote:Originally posted by Jon Boy: I read the codes myself. It's an OBD I computer, so I can enter the diagnostic mode and display the codes on the dash by jumping the terminals on the code scanning port with a bent paperclip (I keep one handy in the center console). There weren't any new codes.
Jon Boy gets the MacGyver award for the day. Posts: 14316 | Registered: Jul 2005
| IP: Logged |
posted
Update: The car has been towed back to our apartment, and Ruth was able to start it up just fine. She listened for the fuel pump first and heard the hum, so maybe it's just going through death throes and will completely crap out later.
Posts: 9945 | Registered: Sep 2002
| IP: Logged |
posted
I would, but deflector dishes didn't become standard until the 1994 model year. This car is from the transitional year when they had integrated deflector antennas. Reversing the polarity is a real pain in the butt because you've got to pull out the computer and rewire it manually. At least it has jeffries tubes for easy access!
Posts: 9945 | Registered: Sep 2002
| IP: Logged |
posted
I've also seen faulty fuel pump relays, try that if all else fails. If you have a test light/multimeter, you could always check to see if there isn't an intermittent electrical problem with the fuel pump motor feed circuit.
Just check for voltage at the motor feed terminal where the fuel pump relay sits when this problem occurs. You can also try jumping the terminals to short the motor out and check for pump operation that way, then you can be certain what the problem could be.
Posts: 4229 | Registered: Dec 2002
| IP: Logged |
posted
Thanks for the advice, Nick. I think I've already ruled out the relay, though—this car apparently uses the fuel pump relay when starting the car and then turns that off and uses the oil pressure sensor to power the fuel pump while you're driving. So that would mean that a bad relay wouldn't be responsible for it stalling.
Posts: 9945 | Registered: Sep 2002
| IP: Logged |
posted
Another thing you could try is having somebody check the pressure at the fuel rail, see what kind of fuel pressure you have, and compare that to a figure in a repair manual. The pump might be running, but it might not be creating enough flow.
I have a hard time believing that a knock sensor can skew ignition timing so far it creates a no-run condition. I agree with your guess that the check engine light is a symptom of the problem, not the cause of it.
It could possibly be contaminated fuel as well, does it happen more when your fuel tank is closer to empty?
Beyond that, I can't really give any more ideas without being there. You got a good head on your shoulders though Jon, you should be able to figure it out. If you have any direct questions, post them here or email me. Posts: 4229 | Registered: Dec 2002
| IP: Logged |
My ex husband and I spent all day Sunday replacing the thermostat on my daughter's car (90 Nissan Maxima) because it kept overheating on her. Thought we had it all good to go.
Today she headed down here (about an hour drive) for a dentist appointment -- and she just called from halfway -- it has overheated again.
Frustrating, it is.
Posts: 9538 | Registered: Aug 2003
| IP: Logged |
posted
could be the rad fan, gone to the dark side... or perhaps even a blown fuse for same... (assuming coolant level is correct and not leaking)
Posts: 675 | Registered: Aug 2001
| IP: Logged |
posted
Radiator fan works (checked that). Doesn't appear to be leaking anywhere VISIBLE (which is what worries me -- where the fluid might be going...)
Posts: 9538 | Registered: Aug 2003
| IP: Logged |
posted
On my Jeep, there's a relay that controls the radiator fan that has a tendency to fail...could be something like that.
Posts: 5422 | Registered: Dec 2001
| IP: Logged |
posted
Usually the radiator fan will only cause a problem when the engine is idling in heavy traffic. If she's keeping a reasonable speed the whole time, there should be enough airflow for the radiator.
I'd bet there's probably air in the coolant system. Did your ex burp the system after replacing the thermostat? Did he check for a clogged radiator? My maxima's radiator gets clogged every once and awhile and I have to flush the system to clear it.
Posts: 4753 | Registered: May 2002
| IP: Logged |
quote: Did your ex burp the system after replacing the thermostat?
Yeah (he used to be a Pontiac/Buick mechanic years ago). I don't know about that second part, though. We drained the whole radiator before replacing the thermostat, and then refilled it afterwards -- how would I tell if the radiator is clogged?
Seems to be okay if she's just running short stints around town. Only when she gets out on the highway for a more extended period of time (when it has time to really build the pressure up) does it have problems.
Posts: 9538 | Registered: Aug 2003
| IP: Logged |
posted
You should be able to feel coolant flowing through the top rad hose. If you pinch the hose then let it loose, you should feel a surge. If not, suspect the water pump or a blockage.
Considering it comes up highway speeds, it may just be the water pump drivebelt, or perhaps incorrect ignition timing.
Posts: 675 | Registered: Aug 2001
| IP: Logged |
quote:Originally posted by Nick: Another thing you could try is having somebody check the pressure at the fuel rail, see what kind of fuel pressure you have, and compare that to a figure in a repair manual. The pump might be running, but it might not be creating enough flow.
Too bad I don't have a fuel pressure gauge. I'm a little hesitant to spend $50 or more to buy one, too.
quote:I have a hard time believing that a knock sensor can skew ignition timing so far it creates a no-run condition. I agree with your guess that the check engine light is a symptom of the problem, not the cause of it.
It's comforting to see that a mechanic agrees with me.
quote:It could possibly be contaminated fuel as well, does it happen more when your fuel tank is closer to empty?
The alleged knock? No, it happens more often immediately after a warm start, like when we run errands and then get back in the car to drive home. Sometimes it just idles low and a little rough. When it's worse, the idle drops really low (under 500 rpm) and then shoots up to about 1500 or so. A few times it's dropped low enough to stall, but only at a stop, never while driving.
quote:Beyond that, I can't really give any more ideas without being there. You got a good head on your shoulders though Jon, you should be able to figure it out. If you have any direct questions, post them here or email me.
Thanks, Nick. I appreciate it. Posts: 9945 | Registered: Sep 2002
| IP: Logged |
Printer-friendly view of this topic
![[Razz]](tongue.gif)
![[Big Grin]](biggrin.gif)
![[Frown]](frown.gif)
![[Smile]](smile.gif)
