missfire, but no DTC
#1
missfire, but no DTC
So i have a 2000 chevy 5.3l, swapped into my 79 chevy 4x4.
runs about 50-60 psi depending on the vacuum of the engine.
I just recently started having a missfire, not bad enough to throw the check engine light on.
I was thinking it may be because i have a exhaust leak before the o2 sensor for some time now and it may have fouled a plug.
NOT THE CASE. i pulled both sides out and they all looked new still ( only month old AC delco's)
ONE DTC CODE I AM GETTING IS IDLE AIR CIRCUIT HIGHER THAN SET VALUE (or something along those lines)
Im not sure where else to go with this now, i even watched my o2 data..
what i am seeing is a b1s1 o2 is say +3.0% to 7%.. roughly.
while b2s1 o2 is say -.05% to -4% roughly.
i swapped a new o2 in the drivers side and it made no difference.
Does anyone else have any pointers on where to go about next? maybe a stuck injector? clogged? im not sure.
runs about 50-60 psi depending on the vacuum of the engine.
I just recently started having a missfire, not bad enough to throw the check engine light on.
I was thinking it may be because i have a exhaust leak before the o2 sensor for some time now and it may have fouled a plug.
NOT THE CASE. i pulled both sides out and they all looked new still ( only month old AC delco's)
ONE DTC CODE I AM GETTING IS IDLE AIR CIRCUIT HIGHER THAN SET VALUE (or something along those lines)
Im not sure where else to go with this now, i even watched my o2 data..
what i am seeing is a b1s1 o2 is say +3.0% to 7%.. roughly.
while b2s1 o2 is say -.05% to -4% roughly.
i swapped a new o2 in the drivers side and it made no difference.
Does anyone else have any pointers on where to go about next? maybe a stuck injector? clogged? im not sure.
#2
any ideas?
also i got a 2000 5.3l, and a drive by wire 04 6.0l i believe it is. can the 6.0l injectors be ran on the 5.3l
i did noticed my 5.3l injectors were 4 nozzles, compared to 6.0 with only 2 nozzles
also i got a 2000 5.3l, and a drive by wire 04 6.0l i believe it is. can the 6.0l injectors be ran on the 5.3l
i did noticed my 5.3l injectors were 4 nozzles, compared to 6.0 with only 2 nozzles
#4
i though the same thing. i ended up pulling injectors out and washing out the rails with fuel, put injectors back in, doesnt seem to have as bad of a missfire, but it still is way down on power. i can only think is that they are restricted
#5
well i put another set of injectors in it today. a used set from a wrecking yard ( ya i know..)
but the problem is the exact same. each injector has power going to it ( tested with a noid light) but is it at the right time? idk...
this is strange how just one day it started to do this..
possibly a cam, crank, or knock sensor>
i really need help with this. anything is appreciated..
Thanks
but the problem is the exact same. each injector has power going to it ( tested with a noid light) but is it at the right time? idk...
this is strange how just one day it started to do this..
possibly a cam, crank, or knock sensor>
i really need help with this. anything is appreciated..
Thanks
#7
does losing ATF count lol?
compression is good. i found out it was showing up on my computer that cylinder 3,4,5 all had some missfires. 3 and 4 were between 50 and 80..
i shut it off and cleared it. nothing came back for missfires.. although it was still missing.
pulled the injector wire on cylinder 3, made no difference, and same with 4
compression is good. i found out it was showing up on my computer that cylinder 3,4,5 all had some missfires. 3 and 4 were between 50 and 80..
i shut it off and cleared it. nothing came back for missfires.. although it was still missing.
pulled the injector wire on cylinder 3, made no difference, and same with 4
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#11
idk how to test a crank, or cam sensor..i could try one out of my brother 6.0l sitting in his garage
SO today i hooked up efi live, and found that cylinder 5 was missing the most..
check volts to the coil, and volts to the injector.. both had 14.. swapped plug wires and plugs.. and no difference...
any ideas?
SO today i hooked up efi live, and found that cylinder 5 was missing the most..
check volts to the coil, and volts to the injector.. both had 14.. swapped plug wires and plugs.. and no difference...
any ideas?
#15
i wouldnt think so, but i was thinking the same thing. i need to check and see if there is a ground for injector 5, or coil pack 5, because those are my missfire problem.
i swapped a good cylinder coil to the bad cylinder and it didnt follow. and the injectors were done before that.
idk where else to go besides maybe a ECM
i swapped a good cylinder coil to the bad cylinder and it didnt follow. and the injectors were done before that.
idk where else to go besides maybe a ECM
#17