I have a ranger that had problems going past 40 mph. The rpms will shift and what not. So far I’ve replaced the throttle position sensor, and fuel filter. The transition was recently rebuilt and the fuel pump looks good. Need thoughts on what else it could be ???
Is the Check Engine light on?
No check engine light
Then what you’re describing is a problem still with the transmission.
I do have plans to get it checked out tomorrow. Is there anything else you could think of that could be causing this problem? @Tester
Perhaps an exhaust problem, specifically the catalytic converter? I suspect that would trigger a CEL, but it’s an idea.
There’re lots of possibilities here. The only suggestion I can make is to have a reputable shop check it out. They’ll probably want to start with a wet/dry compression test, perhaps check for valve timing problems or vacuum leaks, and perhaps for a plugged exhaust system.
Really bad compression, bad valve timing, vacuum leaks, and a plugged exhaust will all cause these symptoms, but then again so could poor spark, bad spark advance, weak fuel supply, and perhaps a few other possibilities that I’m forgetting. Someone needs to look at this hands-on. Someone needs to check the possibilities out with test equipment.
If the engine rpms go up but the vehicle speed doesn’t, that’s most likely due to something going askew in the transmission. I’m presuming this is an automatic, right? If so you might want to try a proper transmission service. That would give the shop an opportunity to inspect for metal debris at the bottom of the pan or sieved from the drained transmission fluid. Might provide a clue anyways. Or maybe the folks who did the rebuild put the wrong type of tranny fluid in. Unlikely but if it happened, this could be the result, and it would be easy enough to fix probably. Over or under filling the transmission is another thing to look for. An automatic tranny has a pump in it, and the pressure that pump supplies has to be correct for it to shift correctly. . So you could have that tested too.