Hello,

This is a Vacuum/FPR question at the end of the ramble.

Inga, my faithful 1986 245DL about to roll past 290K in a couple of weeks has been has had an issue with a high idle of 1500 RPM when the car is in Neutral for four or five weeks. Dropping it into gear would drop the idle on down to 1000. Inga run just fine other than that and have made two 400 mile runs to the kids house to help fix up a nursery during that time without a single blip. The minor issue besides the high idle was a slight sluggish feeling running the hills near my daughters house. Not anything dramatic, Inga just seemed to be not her normal self accelerating up hills.

Found the issue Monday night filling Inga up and doing the under the hood check. The vacuum line going to the Fuel Pressure Regulator had popped off the throttle body and was sitting right by the vacuum fitting. Looked just like it was on there correctly and hid the sucker unless you looked from the right direction. Maybe its just time for new glasses. Slipping that back on solved the the idle issue and I will see what that does for running up and down the hills this weekend when I head back to kids house.

Question is, just how much is the FPR affected by vacuum? Have not really noticed a change up or down in Inga's mileage, got 24 MPG coming back last weekend and for Inga that is pretty good non AC MPG. What does the vacuum connection to the FPR affect, higher engine loads?

Inquiring minds want to know,

Thanks and Regards,

Paul