Quote:
Originally Posted by 02AleroGLS
Does anyone know what would cause a rough idle on a 3400? It runs fine other then that but it was throwing a code for bank 1 lean, and purge control valve. I've changed the FPR, IACV, spark plug wires (Borg warner brand), changed ignition coils, ran B12 through it, llugs are AC DELCO IRIDIUM'S with less then 40, 000 miles on them. I've checked for vacuum leaks the best I can but haven't heard or seen or felt any. And I replaced the MAF. I'm at a loss for ideas.. It's suckjng gas bad too..
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way to thread jack...
just an fyi, the 3400 does not have a "true" bank1 (lean/rich condition) because it cannot tell the difference between bank 1 and bank 2 (only has one up-stream 02 sensor. unlike a v8 truck for instance which has an upsteam for both left and right banks.
btw how did you check for intake leaks?
try this, unplug the MAF sensor and clear the codes (unhooking the battery or w.e u choose to do) and then see if the car runs better with the maf unplugged. this works best if you can view fuel trims. if the if the car runs much better you probabaly have a vac leak (long fuel trims come close to zeroing out rather then be high positives). lets say you unplug the maf, cleare codes and still runs like poo... then you probably have another issue like fuel delivery or bad 02 sensor.
mind you this works BEST when you can see live fuel trim data, can erase and "relearn" fuel trims (unhooking battery for 1o minutes should do the same) and can also test at a steady 45-60mph to get a good idea what your cruise long term trims are.