Rough idle and acceleration problems such as bucking.
What is your question?
I have a 2006 Hyundai Tucson with the 2.7 V6 engine. The engine runs extremely rough when accelerating, but can't accelerate basically out of first gear.
The engine has been replaced along with the throttle position sensor and the computer.
It was suspected that the TPS was not working properly making the engine idle very rough and acceleration almost impossible. All the wiring has been checked multiple times for a pinched wire but the mechanic did not find anything wrong with that. There are no codes being returned by the computer but when monitoring the sensors with the engine running it reports that the intake temperature is -54 degrees and the throttle position sensor is at 34.9 constantly even when idling. The tps numbers start normally at 3 or 4 then after reeving the engine up and down a few times it stays at 34.9 or a similar number even if the TPS is unplugged. The mechanic has tried 4 different TPS sensors during the diagnostic. The old computer and the new computer both report the same numbers when monitoring the sensors. Any ideas on what to check would be helpful.
RepairPal Certified shops can diagnose and repair your 2006 Hyundai Tucson. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.
With an IAT reading of -54° and a constant TPS reading of 34.9% ... You're saying there are NO. Codes?.. What kind of scanner is being used?? Was replacement ECM flashed by dealer???.. BTW.. Why was the ENGINE replaced?.. A little more detail will help us give a more accurate answer!!
The replacement ECM was not flashed, the car started fine, but rough. The Engine was replaced because the old engine had antifreeze leaking into the oil. So it was cheaper to replace the entire engine than it was to dismantle the old engine and repair it (Labor $$$). The old ECM did not give any codes on the new engine but the mechanic had suspicions that it might be the ECM. That's why it was replaced. I'll chat with the Mechanic and find out what kind of scanner was used. Just for clarification, the Mechanic has many years experience and has worked in major dealerships (Ford, Chrysler, GM) before going out on his own. So I don't think it's a simple overlooked item. I have confidence in his abilities. :)
Perhaps I'll upload a Youtube video and post the link here. I'll interview the mechanic and have the scanner running too. Will that help?
Okay, looks like we found the issue. This doesn't answer why there were no codes but once the fuel rail pressure sensor was replaced the engine started working normally again. The vehicle is not fully put back together yet and fully tested but I'll keep everyone informed as to the final result.
There are no error codes from the computer.