I have 740 GLE with about 160K miles in great shape mechanically except for a problem in which the car seems to lose power while driving. The sensation is that the when I start to accelerate the engine wants to "die" and pressing the accelerator pedal further only enhances the problem. However, I can stop the car, turn off the engine, restart the car and it runs fine. I can't seem to pin down when this will occur. It mostly occurs when first starting out in the morning or when the car has been parked a while, such as after work. I let the car warm up fully before driving it, so that's not the problem even though it will still do this little "dying act" when it's fully warm.

Due to the fact that I can "reset" the engine by turning off and on the ignition seems to point to the fact that some computerization is at fault, although I don't believe the car has any of that in it. It's basically a 4 cylinder, fuel injected engine.

I also remember the car doing this last winter but not in the other seasons so it seems affected by cold temperatures also.

Can anyone help? Has this occurred in other 740's? Any ideas on what the problem might be (fuel injectors, transmission)?

I want to thank all of you for taking the time to write and for your wonderful suggestions. I will definitely take all of them under consideration and get this problem taken care of immediately. Andy, I read your posting that you made regarding a similar problem and I want to thank you for probably saving me a bunch of money. I hesitated bringing this problem to my Volvo mechanic until it got to a point where it wasn't intermittent any more and he could conclusively identify the solution. I replaced my spark plug wires about 6 years ago, maybe they're in need of replacement.

This is truly a helpful site!

John, I found that same thing happening to my 88 740 GLE. And it turned out to be Intermittent Spark Plug Wires.

See my posted message titled "Stalling, Jerking, Dying at speed!

I think that the first thing you should check is the distributor cap and rotor, a very easy check and a most likely suspect. Been there done that!

John, I had the same problem on my 87 760Ti. I would be driving, and all of a sudden the car would die. There would be a moment of no power, and it scared the hell out of me. Finally, it got to the point that the car would actually die in the middle of a drive. I took it to my mechanic, and he replaced the distributor and the spark coil. After that it worked fine. Could it be that your distributor is dirty or that your coil has a slight varience in output?

Hope that you solve the problem soon!

When was the last time you changed your O2 Sensor? I had a problem like that which was caused by a bad O2 sensor.

Rene

when is the regular interval to change O2 sensor(s)?

There is no "regular" interval, it just dies and it has to be replaced. Mine lasted 200000Km. Other factors can lead to its death such as rich running and burning oil.

Rene