miss fires no codes

[rusty 1]

hello all : miss fires scan tool snapon . no sodes miss is different cylinder miss fire /cycle jumps to 255 on scaner new plugs cap rotor coil wires .

[astroturf]

Have you pulled and inspected the Distributor Gear?

[mkj54]

[quote][hello all : miss fires scan tool snapon . no sodes miss is different cylinder miss fire /cycle jumps to 255 on scaner new plugs cap rotor coil wires ./quote]


Not sure what you said, In '89 I don't think they gave misfire codes.

[Mr_Bowtie]

Did it mis fire before you did the tune up? Got good BLUE spark at the coil? If its misfiring constantly I would try pulling a spark plug wire off the dizzy one at a time see if you can pinpoint which cyclinder it is.

[rusty 1]

this is on a1997 5.7l . scan tool reads different cyl. dist.gear was fine 1000 mls. ago .when the new motor was installed .

[Phantom]

Does your Snapon tester read live data? is it telling you which different cylinders are misfiring? Does the scan tool read pcm as a 5.7 V8 reading all 8 cylinders to provide info on which cylinder is misfiring? Has it been misfiring the whole time after the swap ?

[rusty 1]

the scan tool read it to be a 95 .dont know about a miss before the swap ,engine blown when bought .scaner reads all cyl. info ,miss all cyl. miss cycle jumps to 255 per cycle this is not normal , new thing to me .today changed comp. found a 97 prom and comp. needs more test drive but still miss 20 miles on new comp .does it take drive time to learn? new comp. in my area junk cars are 150 -350$ scrap makes it hard to find parts they seem to head rite to the crusher.