My car has developed a problem. When I drive on a long trip, it will begin bucking…as if it is not getting sufficient fuel. The check engine light may or may not come on, but the mechanic cannot find anything other than a computer indicated small vacuum leak. I cannot continue to drive this car as it is and cannot afford another. Do you have any ideas?
Take it to another mechanic . . . Fix the vacuum leak . . . Check pressure in the fuel system.
the vacume leak may be between the intake and the head, in which case it will get worse when the engine is warmed up. Is that why your mechanic did not fix it already? find a new, (better) mechanic who, unlike me say, can actually fix things. and do all as mleich suggests.
Make mine another vote for a new mechanic. If the “computer indicated a amall vacuum leak”, then the mechanic should have found and fixed the vacuum leak.
Besides, trouble codes are much more specific than that. They don’t simply indicate a leak, they say what circuit or where or something to provide a good path to follow. There are literally hundreds of codes, so they can get pretty specific.
And then there’s some good old-fashioned ways of finding a leak. Like a can of ether.
Have a parts house like AutoZone scan the car and get a fresh start on this problem. They will do this for you free. Post any codes back for discussion.
There’s not enough info known about the car to make much of a guess but IF there are no codes present my vote is going to be for a fuel pressure problem although there are a number of other things that can mimic this.
When, if ever, was the last time the fuel filter was changed? Fuel filters should be about an every 15k miles event, or more often if fuel contamination is suspected.