Volvo Repair: 1998 S70 loses power, mass air flow, fuel pumps


Question
Hi,
I am hoping you can help me solve a problem(s).  The dealer has stated that they cannot reproduce the problem and there are no codes from the computer.

Last year the MAF (Mass Air Flow) was replaced because the car lost all power.  The dealer replaced the MAF and the car was running fine for the past 12 months.
Over the past month I have been experiencing very similar symptoms.  I have brought the car to the dealer and they have told me that the MAF is working correctly.  They were unable to reproduce the existing problems.

Here is a description of the issues:

1. When I accelerate the car will start to move and then lose all power.  It goes down to idle and the engine idles rough.
This happens for up to 30 seconds and then it will correct itself and take off.

2.  Sometimes while driving the car just loses power.  The tachometer goes down to idle.  I can depress the pedal as far as I like but there is no response.  Then, the car gets the power back and everything is great.  This will last for about 4-5 seconds.

3.  At times when I come to a stop the car stalls.

Please help!  This is driving me crazy.


Answer
Jeff, I would have a fuel pressure test performed and see if its losing fuel pressure intermittently.  Common issue with 850's and 70  series are bad fuel pumps.   You may also be having a cam sensor issue, but that should show in the computer.  Roger