engine missing at 90KM/hr

dave96pu · July 29, 2002

have a 1996 silverado 4x4 vortec, and have a miss in the engine at 90km/hr at light throttle. have new plugs, fuel pump and filter, wiring and distributor are good. Idles fine, have 230000km, can anyone tell me the problem. Chev said replace plugs and I did, no change. please help

95 Silverado · July 30, 2002

first guess would be have your EGR system checked out, it can cause "miss" type symptoms which may only show up part of the time.

describe the "miss" , when does it start, can you make it stop, you say "under light acceleration, what does it do if you give it more throttle, get worse, better?

dave96pu · July 31, 2002

cant feel the miss if I put my foot into it (hard acceleration). Misses not only at 90km/hr but at 1800-2300 RPM in each gears. The truck is still reliable for now but the miss seems to be getting worse. Is there a way to test the EGR system, there is no vacume system for this model.