I've read through many threads with similar titles to this one, but none of them seem to reach a conclusion about what the problem is. I replaced the fuel pump and the alternator within the last few days. The problem didn't become apparent until I road tested the truck today. The fuel filter will be replaced soon. Any other ideas about what to look at? Aside from this issue, it runs fine.
3.4 acts as if there's a rev limiter at 4500 RPM
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4Reak Show
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Just me being a dick, but maybe tacking a workhorse motor past 4500 isn't all that necessary. What's redline, line 5500, 6000 maybe? I've never really needed to be past 4,000 RPMs in mine to get where I need to go.
I know a lot of people come from previous vehicle backgrounds like Porsches or motorcycles or whatever and a lot of folks like going FAST. Totally understandable. But these trucks (specifically the engines) are designed to go ANYWHERE and retain longevity. If going fast is your thing, (as wanting it to rev past 4500 would indicate in my opinion) I would recommend a different platform. Even with a supercharger and 7th injector tuned I'm still not impressed with this motor's SPEED. now it's TORQUE is incredible. It will never stop turning. Just doesn't do it quickly. So higher RPMs seems like a waste of gas to me more or less. And now we're sidetracked I apologize.
That all being said, if you didn't have this issue prior to repairs and now you do, double check everything. It's also possible if you disconnected your battery for the alternator change your ECM hasn't relearned yet.
I know a lot of people come from previous vehicle backgrounds like Porsches or motorcycles or whatever and a lot of folks like going FAST. Totally understandable. But these trucks (specifically the engines) are designed to go ANYWHERE and retain longevity. If going fast is your thing, (as wanting it to rev past 4500 would indicate in my opinion) I would recommend a different platform. Even with a supercharger and 7th injector tuned I'm still not impressed with this motor's SPEED. now it's TORQUE is incredible. It will never stop turning. Just doesn't do it quickly. So higher RPMs seems like a waste of gas to me more or less. And now we're sidetracked I apologize.
That all being said, if you didn't have this issue prior to repairs and now you do, double check everything. It's also possible if you disconnected your battery for the alternator change your ECM hasn't relearned yet.
Thanks. I hope it's not that.
I was thinking the same thing. I did disconnect the battery for the alternator change and wondered if it might have confused the electronics when I hooked everything back up. The old alternator was very weak. Is there anything I can do to help the ECM relearn?
TheDurk
Elite Member
The only thing you can do is be sure you have a representative drive cycle. That is, if you drive only short runs, then do a highway trip or two. Or vice versa.
I do mostly short drives, so it looks like there's a highway trip or two in my near future. Thanks for the advice.
