A few nights ago I was waiting at Sonic for my food to come out. I normally turn the engine off to wait but it was especially cold that night. The engine was warmed up properly.

About a minute into waiting the RPMs started to dip (to around 600) and then jump (to around 1500). It did this until my food arrived about two minutes later. I started off towards home and didn't even make it around the corner of the restaurant when the RPMs dropped sharply down to 500. (Except for one time when it stalled later on in the story the RPMs never drop below 500. The engine would always catch itself at 500). I parked, let it idle for about four minutes, and it continued to drop and rev. I decided to try and make it home, got on the road, and everything seemed okay. It didn't try to stall on the way home.

Cut to today. I hadn't had any problems since a few nights ago, so I decided it was okay to drive.

I was waiting in a left turn lane and it suddenly stalls. It didn't dip the RPMs like the other night, it just stalled. I tried to start it back up right away and the starter wouldn't even turn over. I turned it all the way off and tried again but it still wouldn't turn over. On the third try it started with no problems. I drove it home without any problems.

My airplane mechanic future brother-in-law gave me two possibilities; the ignition's electrical connections are gunked-up with carbon or a vacuum leak.

Any thoughts on the diagnosis before I take it to the shop tomorrow? Any ideas are appreciated.

 

Vaccum leak could cause the RPM up and down. Is the check engine light on?

Stalling might be another problem.

Starter not turning might be yet another problem.

I would also check all battery connections.

 

Sorry, I forgot to mention that there were no warning lights on at all. All the lights came on after it stalled, but when I finally got it back on there was no check engine light on.

I thought it might be the battery connection, but the power stayed on after the engine shut off.

 

When you tried to start it was it in park or neutral?
If nuetral it might be the PNP going bad. But that is only for the starting.

 

I believe I was actually in D with the brake pressed down. It was a panic move, but I'm not 100% sure. I could've put it in park. But it was definitely in park for the second and third attempts.

 

Maybe PNP or starter.
What year was it again?
If it is a 1994 or 1995 try pulling codes and see if it gives you any.

 

It's a 1996 GLT. And um, ahem... uh... what does PNP stand for again. *cough* I seem to have forgotten... [&:]

 

Park Neutral position sensor.
Tells the computers what gear the car is in.

 

Ooooooh... Thanks tech! I'll bring those things up at the shop!

 

Ok let me know if they find anything.

 

In case if the car has not received a good tune-up lately...

https://volvoforums.com/m_48928/tm.htm

See my 2nd post for tune-up items.

And lately some of the popular causes of stall/no-start/erratic idlingare:

- Neglected basic tune-up.
- Fuel pump or pump relay.
- CPS (Camshaft Position Sensor);either the sensor is retiring or poor connection.
- MAF (Mass Air Flow) sensor; either the sensor is retiring or kinked connection.
- Other sensors, etc...

Tell us what codes are stored in the ECU, if you would.

Good luck,


JPN

[IMG]local://upfiles/6892/5CBFDBC66D5E4E9B8B205FD5BDED6256.jpg[/IMG]

 

Thanks JPN! That's a very informative thread. I don't have anything to read the codes, but I'll ask the mechanic if there were any.

 

For a '96 850, you can visit a local AutoZone and have them do a free diagnostic service; they'll hook up a scanner/tester to see if the on-board computer's memory has some fault codes. This narrows down the troubleshooting procedure. BTW, the dealer charges about $100+ for the same service, but certain systems have to be tested at the dealer, such as ABS, climate control, cruise control, seats, etc...

http://www.autozone.com/store_locator/home.htm

If there is no AutoZone close enough to you, other auto parts shops may provide similar services, check with your local shops. You can buy a scanner called OBD-II scanner, but they are rather pricey (a decent model would cost about $160) and it may not be necessary for home mechanics.

Best of luck to you & let us know your findings.


JPN

 

The only mechanic in my town tried to charge me $50 to check my codes.

I chose the 20 mile drive to autozone instead.

 

Well, got her back from the mechanic. He couldn't get it to stall or struggle when it was there. He ended up replacing the flame trap and vacuum hose and cleaned out something (says Carb Choke on the invoice). It's running fine now. Also got an oil change Cost $166.10 in all.

But I also got a list of to-do items:

1. Need a new left axle
2. Transmission flush
3. Right low control arm
4. Right spring seat

plus of course the rear main seal and a new windshield.

Thanks for your help guys!

 

>He couldn't get it to stall or struggle when it was there.
I hate it when that happens[8D]. Cars seem to know how to fool people sometimes.

There is no carb choke on fuel-injected engine (cold idle mixture is controlled by the ECU), so hopefully he cleaned the throttle body.

As to the list,

1. Need a new left axle
Any reason?

2. Transmission flush
Make sure to use Dexron-III/Mercon.

3. Right low control arm
Any reason? Ball joint failure?

4. Right spring seat
If the right one is shot, do both L & R.

Best of luck on the repair.


JPN

 

Well I was driving today and the car started in on trying to stall again. The mechanic said he cleaned out the fuel thing (uh, see above) but the problem persists. The only thing that comes to mind now that the vacuum hose and fuel stuff (throttle body) has been fixed is the ignition. Not sure though. The car has got me aggravated something fierce.

Any other suggestions, no matter how unlikely will be greatly appreciated.

 

It's been in the shop for 4 days but the trail of clues is being followed.

Fuel system is fine, the electrical system is working, and it only struggles when it's idling. So the mechanic is checking the (I can't remember what it's called. Whatever makes the car idle smoothly.)

On a side note, I was planning on getting a Honda here in a few months before getting hitched and moving off to the university to finish our degrees, but it look as though Fridgy (my car, funny story) is sticking with me for a few more years. So now I get to fix everything and get her all primped up with new leather for the steering wheel and wood grain. Anyone have any luck with any of the aftermarket wood trim kits?

 

Not sure about the trim kits but for the idle problem, see attached. I hope they are of some use.


JPN

[IMG]local://upfiles/6892/2D239F0D58B54C4A9797273EB13CE617.jpg[/IMG]

[IMG]local://upfiles/6892/5A99B68E6D7D48A3920A611DCD42A8FC.jpg[/IMG]

[IMG]local://upfiles/6892/69BF531019734732B852D087ED32F7C6.jpg[/IMG]

[IMG]local://upfiles/6892/10855FBC54DF42FB8A04000DC3562330.jpg[/IMG]

 

Thanks JPN!

The mechanic installed a used idler motor (from what I can remember it's called that) and says it's running fine now.

So help me if that car stalls again it's going off a cliff...[:@]