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View Full Version : Heres a problem...


SSStang
03-11-2007, 01:47 PM
What im getting is the engine bogging hard at full throttle. It isnt doing it all the time though, it seems to start about an hour or so of running the car. It does it mostly through the first 3 gears and around 3800-4200 rpms.

Like I said, it runs great the first little while, even until it fully heats up. But only after prolonged driving does the problem begin. I have checked for codes, but I am not getting any. Also, the problems have only started since I installed all the mods.

Thanks for any input/help.

Brian

ausie
03-12-2007, 07:38 AM
What mods were installed when you noticed the issue? Do you notice any difference when getting above 4200RPM or are you basically keeping safe and shutting down? It could be related to the timming since that is a variable the PCM alters as engine temperatures increase along with fuel ratio in relationship to load. If you see any smoke from the exhaust when it boggs down it could be that the A/F is going rich. Sluggish O2 sensors typically will not show codes at first but will fail a diagnostic (pass/fail test) if they are at fault. Since timming does change over the full range of RPM and has a second different timming algorithm above 5000 rpm it could be related to EPROM memory. Whenever you change the intake flow you need to reset the EPROM memory so that the PCM can relearn the changes. The same applies when changing plugs. If you have not inspected your plugs, now would be the time to do it. Worn sparkplug electrodes (or too much gap) will also cause issues at higher RPM ranges resulting in loss of power due to missfire.