Sluggish acceleration

MARY L HERRING

MEMBER
2000 OLDSMOBILE BRAVADA
240,000 MILES

My car is extremely sluggish on acceleration following startup. It will refuse to accelerate for a few blocks, then will suddenly decide to cooperate and accelerate fine. This only happens after we have cut the engine off and then restarted, not when we have been stopped at a light or stop sign. It seems to happen a bit more often and take a little longer to kick in when we are lower on fuel, but still happens when we have a full tank. No problems with exhaust or strange smells. It climbs hills fine and the fuel efficiency seems not to have changed. The only problem I have with stalling is in hot weather, which I have been told is a notorious problem with these cars. I have been told this issue could be the fuel pump or possibly some sort of sensor. I would like to know what the most likely issues are before we go down the rabbit hole with this vehicle.

1 Reply

STEVE W.

MECHANIC
12,968 POSTS

The two most common issues with the 4.3 in the Blazer/Bravada/Jimmy are the crank sensor shutting the engine down when it gets hot, and the fuel pump going bad. Next are the fuel nuts (actually the fuel lines to the injector unit and the pressure regulator on that unit.

As you say you haven't see a decrease in fuel mileage it's probably not the lines or the regulator as those generally kill the mileage because they are leaking raw fuel into the engine.

The most likely issue for you is a failing fuel pump. I would have the fuel filter changed and the fuel pressure tested for pressure and flow. That will give you a starting point to get your vehicle healthy again.