Transit is covered below 1500 rpm.

Hello engine colleagues, I need a help, I have a Ford Transit 2.2 130CV, with 85,000 km. of the year 2006. The problem it has is to be covered. In circulation, when it drops from 1,500 rpm, the accelerator does not respond, on the small digital screen the km/l. The numbers are changed for stripes and apparently everything works, witnesses, speedometer, counting will be very soft. If you go downhill, the rpm. When they increase above 1,500 it sometimes operates again, but it falls below RPM. Starting, the chivatos light, the address hardens and the rpm. They are zero.
The slowdown does not maintain it, so that it works, the revolutions must be raised to 1500, on occasion it has been slowed down and it seemed that it worked to three cylinders, the RPM to 600, on the digital screen the Km/L remains in stripes and blinking and the accelerator does not respond.
In winter with cold he has done it every day, they change the battery and function well for a week and he did it again, changed filters and function almost a week. Only when time changed and stopped doing cold. But now with the days of excessive heat we have, he has done it again.
The error that the OBD throws is U0140, but I think it has to do more with the number of times I have to start the engine, than with the problem.

Hello: as nobody answered you, I took the attribution. Is that transit certain diesel? If so and you have a scanner that allows you to see the data live, the question is: how much is the pressure of the rayl? It is Common Rail, I imagine, I could generically tell you that the Common Rail to maintain or start the engine needs 300 to 600 bar, the other, review of excess return by injectors. (If you do not convince my answer, others will come to correct me, luck.)

Thank you for answering Minicokhe, it is Diesel and Common Rail, Motor Duratorq. I have the scanner but my knowledge to interpret the data is very fair, I suppose that the data I have to look is that of "Turbo Boost Gauge" tomorrow I will look if I get understand me with the scanner.

Hello: the value you have to review, is reviewed in mode 1 of the Scanner, where the PID parameters appear, the one you need to review, should appear as Pid FRP; FRP = (Fuel Rail Pressure) ..

Hello, the apparatus I have is an elm327 adapter with which I use several analysis applications, since not all of the same parameters. In one of them the parameter "Fuel Rail Pressure" at 1600 rpm. Brand 190 kPa, the value I think gives it in kilopascales and with the accelerator stepped to keep the rpm. If it is a problem of lack of pressure, it could be because of any dirt issue in the circuit? A greeting