Magna TR Exec. S/W Manual 2.6l. Trying without success so far to find the mysterious problem with my magna. Starts well and idles well. Accelerates fine until 1800rpm...then won't accelerate past that point, "dead spot". To keep mobile I have to keep changing up gears in order to keep revs under 1800rpm. Firstly, I replaced fuel filter...Problem still there! The bloke at local Mitsubishi(Armidale) had the car for a day to fix said that he thinks it may be the ECU because no fault codes were showing up. Quoted $850 for new one...eeeek!!!. I then had the ECU repaired by an electronics tech. who replaced a capacitor for $38. He couln't guarantee that the ECU was 100% repaired(no way of testing ECU). Put it back in...Exact same problem still there!
Could it be possible that one of the number of fuel regulars is faulty and be causing the ECU to play up? Would very much appreciate a reply from someone who may have some info on this problem.

Hey man best way to rule out the ECU is find someone that has a spare working one and try it.

My old TR did this, throttle position sensor (TPS) was the problem. I would test this first. Mine only did it temporarily after I cleaned the engine bay with heavy cleaning stuff. The TPS was wet. I drove it changing gears at 1750 rpm then did a highway drive at 1750 in 5th, gradually got there, had to slowly increase speed to avoid engine labouring, and after half an hour of driving in 5th I punched the accelerator and it was fine from then on. Mitsu did a fault code test and throttle position sensor left a code in the ecu.

To Shamous69. Did your engine light come on when your throttle position sensor was malfunctioning?

It did yeah.. only very quickly, if I hadda blinked, I woulda missed it. It's weird how you have no fault codes. Maybe the sensor is buggered and wont even send a code to the ecu

An expensive but happy ending...took a chance on a new ECU. Vrrrmmmm...1200rpm..1800rpm..2200rpm..YIPPEEEE!! It goes like a rocket!

My old TR did this, throttle position sensor (TPS) was the problem. I would test this first. Mine only did it temporarily after I cleaned the engine bay with heavy cleaning stuff. The TPS was wet. I drove it changing gears at 1750 rpm then did a highway drive at 1750 in 5th, gradually got there, had to slowly increase speed to avoid engine labouring, and after half an hour of driving in 5th I punched the accelerator and it was fine from then on. Mitsu did a fault code test and throttle position sensor left a code in the ecu.
:stoopid: :stoopid: