Cruising Speed Misfire/Constant Knock Retard

Hello

Pontiac Bonneville 97

3800 II NA 130k miles

Symptoms:

1) Idles poor, always 2) Somewhat consistent multiple misfiring issue, cruising speeds. Occassionally at idle or on freeway. 3) Once it's warm, Knock Retard from .5 to 9 degrees, irregardless of speed. EXCEPT, not under WOT

Replaced Fuel Filter/Sender/Pump, Switched injectors, new plugs/wires/coils, MAP, TPS, cleaned w/GM engine cleaner thru intake, ran oil cleaner, fuel cleaner

NO CODES

LT Fuel Trim Mostly Rich, ST Tends to be Rich

Any thoughts??

Reply to
daron.fine
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Reply to
Shep

What are you seeing for vacuum readings? How did the old plugs look? Timing steady?

Steve W.

Reply to
Steve W.

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