no fire to spark plugs

btaylor · Post by **btaylor** » 02 Nov 2012, 21:22

Big problems with my '97 850..I drove the car through a puddle of water about 8 inches deep at about 35 mph, all of a sudden I heard a kind of whirring or winding sound, started losing power and coasted to a stop. Tried to jump the car to no avail.

The next day we found that the serpentine belt had frayed (not broke) and slipped completely off of the pulleys.
Also, the coil pack is supplying fire to the distributor, but not to the spark plugs. The engine turns over but there's no compression.
Any ideas?

Post by **rspi** » 02 Nov 2012, 21:28

You can check this thread:
https://www.matthewsvolvosite.com/forums ... =1&t=52585

Post by **precopster** » 02 Nov 2012, 21:39

Definitely go with the Lawnmower Syndrome for the lack of compression, however sounds like there's water under the distributor cap which is shorting the high voltage spark.

Undo the 3 10mm long bolts going through the cap and thoroughly dry it out. You should be fine then do the oil trick.

btaylor · Post by **btaylor** » 03 Nov 2012, 17:32

forgot to mention that the cap and rotor were changed the next day, still no fire to the plugs...

btaylor · Post by **btaylor** » 03 Nov 2012, 21:00

By the way, please pardon my ignorance, but what is "lawnmore syndrome?"

Post by **precopster** » 03 Nov 2012, 23:16

I can't account for how a spark disappears once it leaves your main spark lead other than the wrong cap or a faulty rotor. Check the spring loaded carbon button to be sure it hasn't dislodged.

Lawnmower Syndrome is when you crank the car for a short period with no firing or start the car for a very short period (for example for afew seconds to pull the car back just to move the lawnmower out) This allows unburned fuel to wash down the cylinders thereby washing off the engine oil that helps to seal the cylinder and cause compression. By adding some oil (a teaspoon) into each cylinder through the spark plug hole and cranking, the compression should be restored.

How have you confirmed no compression? Have you used a compression tester? Have you removed the cam cover (one x 12mm bolt) to confirm the cambelt is intact? Also how have you tested spark? With coil lead at 5mm from ground while cranking?

btaylor · Post by **btaylor** » 04 Nov 2012, 14:16

Removed the cam cover, cambelt looks good

btaylor · Post by **btaylor** » 05 Nov 2012, 20:45

Does the 850 use throttle body or multi-port fuel injection?

Post by **jblackburn** » 06 Nov 2012, 08:26

Sequential FI. The injectors are under the silver rail at the top of the engine.

btaylor · Post by **btaylor** » 21 Nov 2012, 11:16

Well, changed the coil and now there's
fire to the plugs, new distributor cap, rotor button and new plugs, tried the lawnmower syndrome thing, the cambelt appears to be ok, but stiill no compression. Does the serpentine belt being off have any
significance to this problem?