Question1998 CHEVY S-10 VERY BAD MISS AT APPROX. 1500 RPM. DEALER REPROGRAMMED COMPUTER, CLEARED CODES AND SAID I HAD A BAD EGR VALVE. REPLACED EGR. MISS STILL PRESENT. ACTS LIKE AN EGR VALVE. MISS HITS VERY HARD. STARTS & RUNS GREAT OTHERWISE. WILL NOT REV BEYOND MISS WHEN IN ANY GEAR. 4cyl
AnswerI hope this isn't your problem, but I have a 95 car, and with a symptom something like that. it would get to shuddering real bad.
A compression test found a broken valve spring. It had two springs on each valve, one inner, and one outer. It would run great till a certain RPM.
On an S10 I had in my fleet at work, I needed to replace the plug wires every 20,000 miles.
I would connect a vacuum guage to your engine, and see what the needle acts like during the miss.
Van
Van
