07MonteCarloSS

Are the cylinder numbers in EFI numbered differently then the normal 1-3-5-7 and 2-4-6-8? i ran a datalog on my dads 2000 suburban with 5.3L looking for which cylinder is misfiring and he had suspected 5 and 7...well looking at the PIDs its showing cylinder 3 and 4...4 being a dead miss and 3 being intermitten. if they number them 1-2-3-4 instead of 1-3-5-7 then this would make sense. just wanting to make sure im correct. thanks! also is there any way to tell if its a clogged injector or a coil pack causing the issue using EFI scan tool? i know how to see the misfire but not sure how to tell if its the coil pack not firing or if its the injector clogged causing the problem. truck has 285k on it with original injectors and coil packs so either could be the cause...just not wanting to throw parts at it instead of finding the actual issue. thanks again!!!

ctmcamaro396

Just swap the coil with a cylinder thats a know good one and see swap the plug wire too if no change check for compression and then look for the injector pull the plug and look for signs of over fueling and see put the spark plug in the wire hold it to the head and have some one turn it over to see spark.

joecar

They should be numbered the same (odd # on odd bank, even # on even bank).

jimmyblue

iTrader: (11)

I have seem people mention that the indicated cylinder in
misfire detects can be off by one, I think this is the PCM
and not the tuning software. I haven't seen it myself, but
have seen the right cylinder indicated on a bad plug wire.
Component swapping is a good diagnostic method anyhow.