Volvo Repair: 1998 volvo s70 loses power and stalls, fuel pressure regulator, volvo mechanics

Question
Hi:


When driving my 1998 s70 non turbo, at freeway speeds I will fell small loses of power. The car does not stall, however it feels like it is running out of gas.

When I reduce speed and slow to an idle, say at a stop sign,  it will stall. It will finally start again after trying to ignition over and over. Again, it just seems like there is no gas.

The problems are intermittent. I took it to two different volvo mechanics and they could not reproduce the issue after driving the car for about two days.

Error codes that are generated are:

433: Faulty Knock Senor
231: Fuel Mixture Issue

Also,they found a vacuum leak under the intake manifold.

Since they could not reproduce the issue, they could not say if these codes indicated the exact problem.

What do you think?

Thanks!

GREG  

Answer
   Greg, when it dies and you have difficulty starting it, try this. Pull the vacuum line off of the fuel pressure regulator and see if there's liquid fuel in it. If there is, replace the fuel pressure regulator. If there's not, e-mail me back. I assume you repaired the vacuum leak?

Mark