2009 Toyota Corolla misfire

Anyone know the best way to find out why a ECM would be shutting number four injector pulse down. This car will idle in my shop for hours with no miss as soon as I get on the road it shuts number four injector off I have looked at coil ramps and swapped plugs and coils between cylinders also I have watched injectors and swapped them still number four. Looked at the cam and crank signals they seem fine. I drove it and watched scan data misfires I kinda feel like the ECM is seeing lots of miss fires on cylinder 4 right before it shuts off injector during that time I can't feel it in the car then boom when the ECM shuts off injector it is like night and day car stops having any power of course cause it turns into a 3 cylinder lol

tim, have you performed a relative compression test?

What are the fuel trims doing at idle and high rpm? Are the O2's responding properly?

Does the car have any unusual vibrations when in gear?

Thanks

Paul

mechanical, diagnose cylinder # 4 valve train, watch a vacuum gauge flutter for valve issues, running compression etc... swap injector too.

Does this Toyota actually have intentional shut down?? Or is it just a driver failing intermittently? I’d try unplugging a coil on another cylinder to see if the computer shuts the injector off. Just to see if it really is intentional shut down. Then go from there

moderator please delete the zippy share links i shared imo zippyshare is like a virus lol pop ups and i never could get the files to show up here is the same pids from a test drive notice how o2 and stft flat line these are mediafire. the secound group of pids is idle

www.mediafire.com/file/dftfk6rxrix7mgi/2...5_21.48.33.pids/file
www.mediafire.com/file/26ie6ei36qofhl2/2...5_22.16.57.pids/file

go to snap-on and download the free program shopstreamconnect to view files then open with shopstreamconnect.

the first one is both cams and the second one is injector that was in cylinder number four it has been moved to cylinder number one.

www.mediafire.com/file/szui8u8liuruist/t...9_both_cams.vsm/file
www.mediafire.com/file/5qpy5384a7ookm8/corrolla.vsm/file

i cant get the files to open

@cheryl hartkorn i had to make a folder in a area that shopstream could see and move the files there before i could find it with shopstream it was a challenge lol but i got it so i know it works

i asked for help on iatn but i guess you cant reply to a help request that you started on iatn so i dont think i will be doing that again lol

Are misfires detected by anything other than the crank sensor?

I guess a transmission problem could be a culprit

I also have to agree with possible mechanical and doing a relative compression test. I chased a very similar misfire on a 2011 Sentra. I misread the waveform on the relative compression test, but once my error was pointed out by the experts on this forum, I did a mechanical compression test (which required removing the upper intake) and indeed had a significant loss of compression on the offending cylinder.

okay guys i know i did a relative compression test with the scan tool thru the functional test and compression looked good but i did not save that screenshot but i did get to drive this thing and i can confirm that data stream shows number 4 is missing right before the ecm shuts injector off it is kinda kewl because i can actually prevent injector shut down if i let off the throttle i also saw a couple misses on cylinder two i have two pid views showing me doing this on two different test drives.

www.mediafire.com/file/9zflp692zdopslb/2...1_17.16.15.pids/file

www.mediafire.com/file/6prj9gfluibi3dj/2...1_17.35.49.pids/file

because i did not save the compression test screen shot and this looks more and more like mechanical problem i decided to revisit the compression this time with a gauge it showed between 165 and 175 per cylinder i then decided to do a running compression test with the gauge (since i dont have a kewl pressure transducer for my scope ) it seemed that it was about 40-50 hard to read of course and around 80 to 100 psi on a snap throttle all cylinders the last thing i did was a cylinder leak down with shop air it seems that an exhaust valve is leaking on cylinder two all the other cylinders seem to be great including number 4 just wanted to close this one out sorry for the delay i have been crazy busy.

again i cant say it enough thanks to all that helped and thanks for all you guys do!!!!!!!!!!!!!!!!!!!!!