engine hesitation
Asked by yamaha May 24, 2009 at 02:45 PM about the 1997 Chevrolet Monte Carlo LS FWD
Question type: Maintenance & Repair
My car has a bad hesitation that seems to go away under full throttle. The hesistation is most prominant under light loads around 50km/hr and 110km/hr. Several mechanics have inspected the car but cannot find anything wrong. There are no codes, it only happens about 80% of the time, the problem isn't getting worse and has been present for about 3 years. Do you have any suggestions?
3 Answers
Fuel Pressure is very important on these vehicles - Make sure that Fuel pressure and fuel pressure regulator are working properly ( 41-47 lbs / 284-325 kpa ) If that is good I think next you would go to the TPS sensor and do a voltage sweep test on it - Ohm testing is not a sufficient test. Lastly I would go to the MAP sensor ro make sure it is getting proper vaccuum from the manifold as it is directly fitted to it it may get carboned up and check for proper voltage curve uner acceleration, Good Luck
if you have an automatic trans get ur tranny checked; ur converter may not be getting all the oil it needs at certain speeds in certain gears at certain loads. or 2 of the gear sets could be very worn, i had that problem with my dad's Pontiac Montana at around 80km/h. then get ur sensors checked such as load sensor, vacum and engine speed sensor. even if ur tach is working good the electronics between the engine and trans may not b communicating right. worst case senario ur motor just doesn't have any low end balls any more and 80% of the time for 3 years dude...... just No! get it checked when a problem first shows up.
Could a bad coil cause hesitation or a crank sensor be the problem ?