Why does a 93 Caprice engine seem like the fuel shuts off at times and run great other times?

Answer 1

My 93 Caprice started with a significant hesitation, that eventually morphed into a no run condition. I replaced the distributor cap and rotor, ignition module, ignition coil, fuel pump and fuel filter all to no avail. I had to have the car towed into a repair facility where they diagnosed the problem as a faulty pickup coil (located on the distributor shaft below the plate where the ignition module mounts. The car hasn't quit running since. Good Luck! Start with the fuel filter, either on the firewall or in the fuel line under the car. Do you have water in the gas? Are your injectors clean? Are your air filter, PVC valve clean? A lot more info required here. try the map sensor , it can be a vaccuum leak and not the fuel at all . If this doesn't solve the problem you should try the control module . Most modules when bad seem like the fuel is cutting off when actually it is the spark . The in-line fuel filter under the driver's side of the car may be dirty or clogged. Be careful replacing it b/c it spurts gasoline for a couple seconds. Keep track of the fuel guage also, if it is less than half (usually a quarter tank) and this symtom occurs, the fuel pickup in the fuel tank can be off by this much and the fuel will slosh in the tank and not stay under the pickup hence the cutoff of fuel symptom. Occurs on hard left corners when all the fuel flows to right,due to pickup orientation. The in tank baffle can break (there glued on the plastic ones)and cause this also. The harder the left, the more the cut off of fuel to the point of stalling the motor. Replacing the fuel pump and sender and/or fuel tank would be the cure if this proved to be the reason. I also keep my 91 at least half full of gas because of the known issue of poor baffleing on the stock plastic tanks, guess they never figured anyone was gonna put a performance suspension and 450 HP in one eh... lol One other thing needs to be considered with this type of problem is that after about 75,000 miles the throttle body develops a fairly significant carbon build up. You can clean it yourself or a Chevy dealer will clean it for under $200. If you choose to clean it yourself I recommend you spend some time at a junkyard and practice on one of their cars so you have an idea of what you are getting into. VBD Could be an electrical connection. I though my problem was fuel oriented too, but worked great when I fixed a similar sounding problem by replacing the distributor cap/rotar. Ran great and smooth afterwards. Startup better too.