Volvo: 96 Volvo 960 Sedan, fuel pressure regulator, vacuum leaks

Question
Ray:

Thank you.  It appears to be the #3 coil is not firing correctly.  Is this an expensive repair?
Or a simple spark plug change.

Thank you,
Volvo Lover
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Followup To

Question -
Hello Ray:

I'm hoping you can help me before I dump another full weeks payroll in my vehicle.  I have a 96 Volvo 960 with a rough idle.  This occured a few months ago and my mechanic performed an oil change, spark plugs, replaced the camshaft center and replaced the timing belt  The problem is back again, what do you suggest?

Thank you in advance.

Answer -
Tonya,
A 96 will have what the industry calls OBD II. That is the type of diagnostics it will have and if the car is running rough there should be some codes. Have them read and follow the clues. If there are not codes look at the engine while it is running, is it shaking? If not I have seen a few cars that the motor mounts are so bad on that the smallest of vibrations are felt in the body of the car. See the mounts sag so much that the engines oil pan lays on the sub frame and all the vibrations is then transfered into the body of the vehicle. If there are codes follow them. I have encountered fuel trim codes caused by vacuum leaks in the engine and those leaks cause a rought running engine. There also have been the cars that the fuel pressure was off causing lean running and also a few that the fuel pressure regulator is leaking fuel into the vacuum line that is attached to the regulator. That causes a rich mixture and at times rough running, and poor performance and fuel milage.

Answer
Tonya,
I know that a used coil will run about $30.00. Not hard to put in at all. As long as you are so close go ahead and replace the plugs also. Plugs are about $2.00 each. Be careful not to mix up the coils as you pull them off to replace the plugs. Many people use a marker and number them on the top.