1993 GMC Sierra 4.3L drivability problem

Recently it began backfiring thru the TBI under load (going up a grade). Sometimes it's severe, sometimes it pops just once. Cap and rotor were changed but no no change in the symptom. Drives fine while cruising, idles fine, no SES light or codes.

Any pointers out there?

Reply to
wrench
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Reply to
benick

This sounds like a timing issue. When you go up a grade, or have a loss of power, it sounds like your timing isnt retarding enough. I cant remember though whether you have vacuum advance on those vehicles anymore or not.. If you have it, check for a vacuum leak. If you dont have it, the check your crankshaft sensor.

Reply to
pkurtz2

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