Cylinder 5 misfire 1998 Chevrolet Silverado 5.7

Did you change spark plugs and wires? If you do so, check compression

My 1998 has about 270000 on it I just replaced the spider injector but it was saying misfire on cylinder 5 running good has all the power it use to have thought this might help

You know had same problem. Did everything. Plugs wires ,vac.test.copression,fuel pressure ext.come to find out it was the spider injector for that cylinder. The plastic nozzle at the end was or had melted. I replaced just. One . Worked fine. If I had had the money I would have replaced the hole thing.

I don’t know if you ever found the problem.”, but it’s your fuel pressure regular under the upper intake plenum. It leaks raw fuel straight to a port that drains into cylinder 5. Makes for rough idle and bad exhaust smell. Should cost you about $75 to fix if you do yourself for the regulator and upper plenum gasket kit. Not too difficult, just take careful notes on what bolts come out of where in the plenum.