Hello Everyone,

I have a '96 850 GLT wagon, non-turbo with a 5 speed manual that has a 190,000 on the odometer. At 180,000 I did the usual tune-up (every 30K miles) and replaced the air filter, cap, rotor, flame trap, plugs and cleaned the throttle body. I did not replace the wires, and they have over a 140,000 on them. I now have 190,000 on the car. The car is kept in an unheated garage and I live in Connecticut. So it does get cold in the morning. Recently, when my wife starts the car for the first time in the morning (it's garaged overnight), it runs rough, like it is firing on only 3 cylinders. You can smell unburned fuel. After the car runs a mile or so, the engine runs smoothly, and there is nolonger the smell of unburned fuel.

At first, I thought the problem was due to the spark plug wires, because they have over 140,000 miles on them since they were replaced last with Volvo OEM. But now, I'm having second thoughts. The spark plugs I put in at 180,000 were the Bosch Platinum +4 Plugs that have 4 prongs. The OEM Volvo plugs have 3 prongs. To my knowledge, Bosch is the OEM supplier to Volvo for plugs. However, I have seen comments on this website, that Bosch plugs will adversely affect the way the engine runs. I haven't changed the wires yet, but I would like to know if any one has had problems installing the Bosch Platinum + 4 plugs over the Volvo OEM 3 prong plugs? Thanks for your comments in advance.

Hugh