Disclaimer: I have searched the forum and have replaced a lot because of it still same issue.
I'm throwing a cylinder 1 misfire regularly. and if I wait long enough and don't clear the code I will get a misfire code for every cylinder as well as a multiple misfire code.
Things I have checked/replaced
compression is good across the board all within 5 pounds.
Has spark on all cylinders
checked all grounds
tested each connection to each injector, all working
Tested fuel pressure, solid 49 PSI with a little throttle, jumps between 40 and 49 at idle
vacuum seems fine ( I'm not to wise with how vacuum works or where to look)
now to what I have replaced.
TPS, cap, plugs, plug wires, rotor, Both 02 sensors (did Bosch before I knew better, literally only 50 miles on them though)
Things suspicious to me is the fuel pressure at idle. I just couldn't find anything saying it jumping ten pounds was normal when I searched. This would back maybe it being the regulator, as cylinder one is the farthest from the regulator? Or a coil? I know it could be the CPS but my gut says something else what should I look for in the vacuum system? I'm seriously just spit balling this problem and seeing what anyone has to offer what has me licked it is slowly happen to ALL cylinders If I don't wipe the code.
Any help would be awesome I'm about to just blanket the problem and replace everything I haven't yet
I'm throwing a cylinder 1 misfire regularly. and if I wait long enough and don't clear the code I will get a misfire code for every cylinder as well as a multiple misfire code.
Things I have checked/replaced
compression is good across the board all within 5 pounds.
Has spark on all cylinders
checked all grounds
tested each connection to each injector, all working
Tested fuel pressure, solid 49 PSI with a little throttle, jumps between 40 and 49 at idle
vacuum seems fine ( I'm not to wise with how vacuum works or where to look)
now to what I have replaced.
TPS, cap, plugs, plug wires, rotor, Both 02 sensors (did Bosch before I knew better, literally only 50 miles on them though)
Things suspicious to me is the fuel pressure at idle. I just couldn't find anything saying it jumping ten pounds was normal when I searched. This would back maybe it being the regulator, as cylinder one is the farthest from the regulator? Or a coil? I know it could be the CPS but my gut says something else what should I look for in the vacuum system? I'm seriously just spit balling this problem and seeing what anyone has to offer what has me licked it is slowly happen to ALL cylinders If I don't wipe the code.
Any help would be awesome I'm about to just blanket the problem and replace everything I haven't yet
Senior Member
make sure each injector is spitting fuel.
i had a similair problem and threw 200 dollars worth of parts at it and it turned out to be a wire rubbing on the exhaust manifold heat shield and causing a short.
check all the wiring, not just the grounds.
goodluck
i had a similair problem and threw 200 dollars worth of parts at it and it turned out to be a wire rubbing on the exhaust manifold heat shield and causing a short.
check all the wiring, not just the grounds.
goodluck
I've traced the whole wiring harness and nothing seems like it would be causing a problem. I also did a 703 injector swap today, Just cause I finnaly got em in the mail. still the same issue but I also got a code for high voltage on the coolant sensor, which runs with the same harness as the injectors, but once I cleared the code it didnt come back. But the misfire code still comes back within driving a few miles. could that maybe be a sign there is something in the wiring I could be missing? anyone seen a problem like this?