1996 960... stalling issues

dyoung62 · Post by **dyoung62** » 21 Aug 2011, 20:43

Hi All! Just purchased a 96' 960. I have replaced the Air Mass Censor, the ignition coils, Harness repair kit as well. The car starts right up, runs well... but can stall at a light, or if i turn it off to go inside, when I come back out, it wont hold the idle and dies... I have to race the engine a little and keep the idle up...when I shit into drive, or reverse it dies...... Im frustrated, as two so called volvo mechanics dont know what the problems is? Thoughts?

peteco · Post by **peteco** » 22 Aug 2011, 07:13

My 97 960 had somewhat similar problems. The coolant temperature sensor was bad.

Here is some info. You can do a resistance check. The sensor is located on the thermostat housing

http://caunter.ca/volvo960/wb14823.pdf

Bought the sensor at Autozone; looked like the original; $35

When it fails the resistance is high and the computer thinks the engine is cold so it commands a high fuel rate. This is OK when the engine is cold but when warm it is dumping too much fuel into the engine and it stalls.

Post by **precopster** » 22 Aug 2011, 07:59

My '93 960 has the same problem. On some days it drives perfectly. One time it cut out at 60mph on the highway. Then I shut it down for 30 secs, restarted and it got me home with no dramas.

My coolant sensor is new, my loom has been rewired, the fuel pump is new. However the fuel pump relay is going in next. On some cars with age you do have to throw parts at them.

My 960 will not restart unless the ignition is kept off for 15-30 seconds. Very hard to fault trace it with cars in your rear

dyoung62 · Post by **dyoung62** » 22 Aug 2011, 09:52

Peteco.... thanks i like the sound of that and rings very true... becuase the gas milage has been awful..... that would explain it...

Post by **precopster** » 22 Aug 2011, 17:21

The gas mileage on 960s is generally not spectacular. Expect b/w 15-19mpg city and 23-27mpg highway.

The general condition of your car will determine the efficiency or otherwise of your engine. You didn't state how many miles are on your car. Also is it a sedan or wagon? (Wagon's have a 160lb weight penalty to begin with) Does it use oil? Have you done a Stage 0 tune-up? (lots of threads here about this) Have you performed the air cleaner box mod which ensures a faulty air temp bulb won't give your car heated air from the exhaust manifold at all times? This has a bearing on both performance AND economy.
If you have done more than 120K miles on the O2 sensors you might want to look at these, particularly the front one.

I hope that the temp sensor sorts out your problem but if it doesn't start looking around at the other items mentioned. Keep us posted

dyoung62 · Post by **dyoung62** » 24 Aug 2011, 13:26

Appearently no one can figure out the poblem.. thought it was the fuel pump, but thats OK, everything else is checking out Fine, all sensors, etc..... makes no sense at all... car has 134kmiles, sedan ...... the word lemon is popping into my head. Might have to try and cut my losses....

Post by **precopster** » 24 Aug 2011, 16:44

Does the problem occur when cold or only upon restart?

If so I would be looking at things affected by residual engine bay heat.

Is the fuel relay in the engine bay? On earlier ones it is.

Also I found a thread on brickboard which seems to have fixed my problem for the last three days.
The valve guides if not cleaned by removing the head can accumulate a lot of sticky residue and this makes the valve not fully seat home and cause a lack of compression in one or more cylinders. The writer of the article seemed to suspect fuel system cleaners as being the culprit. This problem can apply to the fives as well I would imagine; same design.

The "FIX" is to bring the engine to around 5,000 rpm in low gear and drive it for around 10 mins this way. This will not harm the engine, but will heat up the goo inside the valve stems and force it out with friction. It will then drop into the combustion chamber and be burned off. The reason it won't affect cold motors is the goo has hardened and becomes a film while the engine is cold.

I was a little apprehensive but tried it last week as like you, I was getting fed up and it was occurring upon restart. Immediately the idle was smoother and the intermittent MISS I was hearing on idle disappeared. Well yesterday I went for a good run for three hours for business and it didn't miss a beat. I started and stopped the car at least five times while warm and it idled perfectly each time. This is the car's original head with around 110K miles, the "OTHER" head supplied by my mechanic seemed to give the same problem before all the valves were bent earler this year (my fault, not the car's)

Give it a try; looks like you've got nothing to lose and everything to gain.

dyoung62 · Post by **dyoung62** » 29 Aug 2011, 09:55

hmmm, Interesting.....will try anything.... thanks

Post by **precopster** » 29 Aug 2011, 16:36

As an update to the "FIX" I did last week the car has run faultlessly since then and has NEVER STOPPED. I'm as surprised as anyone about this fix.

In fact I forgot all about doing the fix and this post as the car has never missed a beat since. Hope the same for you!!

dyoung62 · Post by **dyoung62** » 31 Aug 2011, 14:08

Interesting..... now we(mechanic) is thinking it is the Fuel Injection Relay. if that doesnt work, then I am shifting her into low, and driving around at 5,000 rpms for 10 minutes..... good lord this has made me very cranky.......