This can be a number of systems problems. I'm assuming it is a 5.7 L V-8 with TBI style fuel injection since I have addressed this problem commonly in those vehicles and this milage range.
Your problem could be tune-up related depending when the distributor rotor, cap, spark plug wires, and spark plugs were replaced. I recommend a thorough tune-up if it has been more than 30,000 miles on spark plugs, cap, and rotor; and 60,000 miles on the plug wires. If that is all current, it could be your TBI injectors. Looking at the high milage you indicate, they could need replacement (2 each in the TBI)
Apart from that it can be sensor issues such as Mass Air Flow etc. These should be throwing a code that can be read by purchasing a realtively inexpensive tester/reader that plugs into your data port under the dash left of steering wheel. You plug it in and turn the key on and count the times the check engine/stop engine light flash to determine codes. A booklet that comes with the reader will tell you what the most common codes mean.
You may want to have the codes read by someone with a diagnostic reader/programmer if the cost is not prohibitive for you. Of course, if this is not the 5.7L engine, or not the 220 TBI fuel injection fuel system, much of this advice is not relevant.
Sunday, September 19th, 2010 AT 7:24 PM