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Captiva never revs up over 1500-1800 RPM

12K views 20 replies 6 participants last post by  Aussie Ed 
Mariano, after reading your first post my initial reaction was the nuclear option – cut your losses and get rid of the car. If you’ve bought a turbo charged diesel with automatic transmission and it’s uncertain what’s been messed about with then it’s likely to become a money pit.

How sure are you that the automatic box is really fixed because, even if you get the engine running right, if the auto box fails again then it’s not economically viable to repair it (not in this country anyway).

If the DPF and EGR valve have been deleted then the ECU should have been remapped to accommodate this otherwise there would be no proper control over the fuelling and running of the engine. The engine could have uncontrolled horse power and over-torqueing, resulting in damage to engine components and possibly auto box.

You’ve already had some good advice from Ches but you’ve got so much going on that nobody can give you a simple road map out. That said, I’ll post some further comments which might help..
 
Collapsed air filter element / leakage at intercooler / inlet duct hose; I assume you have checked these already inc intercooler for leakage and the duct hose running from the intercooler to the throttle box.

Collapsed fuel filter element. The 2 litre Captiva has a single element fuel filter mounted on the bulkhead, I have read that the filter bowl needs to be really severely tightened up to avoid air / fuel leakage.

The tank pump should deliver 50 psi, not 5 as you reported. It doesn’t matter anyway, the car is starting OK and the transfer pump inside the HP pump takes over once the engine has started.

The Suction Control Valve (SCV – also known as Fuel Metering Valve) in the HP pump should have been renewed. Sticking SCV would limit the fuel flow unpredictably however it usually results in difficulty starting which you don’t seem to have.

You’ve already had the injector needles etc replaced and, presumably, the leak-off rate checked on a test stand. However, you also need to check the leak off return pipe all the way to the tank for blockage.

You need better diagnostics equipment, possibly even use paper clip to check fault codes and see if you get any further info.

You have changed the MAF and MAP sensor – are you using OEM sensors? Aftermarket sensors (even if they’re marked Bosch or Delphi) are sometimes Chinese copies. Incidentally if it runs better with the MAF sensor unplugged it usually means the MAF is faulty.

You say you changed the MAP sensor which also includes the IAT and the measurement with both scanners was the same. Have you checked the ambient temperature and barometric pressure reference reading in the ECU and verified that it is the same? I believe the ECU has its own barometric pressure sensor and shares the IAT sensor mounted on the chassis.
 
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