Engine

Diagnostic Tool

Firstly, anybody embarking on an engine conversion should have appropriate diagnostic tools. Without diagnostic tools, trying to diagnose a no start condition is essentially a guessing game.

We have always had success with INPA and using a K+DCan cable. However, INPA can often be tricky to find a good installation copy and install. More recently we have found that the Bimmer Tool app on Android, coupled with the same K+DCan cable seems to work well. Not only does it enable fault codes and live data to be read, it also allows you to log data which is important when trying to diagnose an issue with the engine performance.

No Start?

The majority of questions we get asked are relating to starting of an engine for the first time after install, so we have written down the most common reasons, things to check, and how to fix them.

• Is the engine cranking over on the starter motor? The engine will not start magically, so if it is not cranking over then you should check the trigger for the starter motor, this is usually a thick black wire on the engine harness.
• Is the main relay turning on? This is usually a blue relay and is controlled by the ECU. This often gives an indication if the ECU is awake. In general, the main relay should turn on when ignition is applied to the standalone loom. When ignition is removed, the main relay should not turn off straight away, usually after 15-30 seconds.

Is your ECU waking up?

If the above are correct, and the engine is not firing, then the next step would be to plug in diagnostics and check a few things. When using a House of Torque unlocked ECU, the three things that are required for the engine to fire are as follows:

• Sufficient rail pressure. The injectors will not fire unless rail pressure is around 300 bar.
• Crankshaft signal – this provides the rpm signal so check for this in diagnostics. If you have no RPM signal then it is usually down to a faulty sensor or the trigger wheel missing on the end of the crankshaft.
• Camshaft signal – this would usually show an error code if missing.

Rail Pressure

By far, the most common issue relates to point number 1, and a lack of rail pressure. There are a few checks that we recommend.

• Is diagnostics staying connected whilst cranking? We have lost count of the number of faulty ignition barrels that we have seen, causing the ignition feed to be lost when cranking.
• Is your pre-supply pump running? This will need to be working to supply enough pressure to the high pressure pump.
• Have you got your fuel pipes the right way around to the high pressure pump? The feed is always connected to the port which is closest to the front of the engine.
• Have you got 12v on pin 1 of the high pressure fuel pump?
• For DDE 4 only, what is your presupply pressure reading? If this is low then the high pressure pump will not make pressure.

If the above points check out okay, then it sounds like things are okay in terms of set up.

If you are still low on rail pressure, then it is worth considering the following. With rail pressure, an absence of pressure can be attributed to two overriding things, either pressure isn’t being made, or it is being lost.

Reasons why pressure isn’t being generated can be:

• Presupply issue
• HP pump issue
• HP pump control valve

Reasons why pressure could be being lost:

• Injectors leaking either to the return or into a cylinder
• Faulty or contaminated rail regulator

Another consideration is whether the rail sensor is working. If you suspect that you do have enough rail pressure but it is not reading correctly, try starting with the rail sensor unplugged. This will make the ECU think that there is enough pressure to start and will try firing the injectors. If the engine then starts you will know the problem lies with the rail sensor.

Do you have the right ECU?

It sounds daft, but despite our recommendations to get an engine with an ECU, we still end up with customers who have a mismatch.

When it comes to M57 ECUs, an ECU meant for piezo injectors will not start an engine with solenoid injectors and vice versa.

Running issues?

If you have any sort of running issue then we recommend to start with diagnostics.
A lot of issues in terms of performance either come down to fuel or boost. Therefore, we recommend logging:

• Requested boost and actual boost. This will tell you if it is hitting the target, overboosting or underboosting
• Requested rail pressure and actual rail pressure. This is a quick way to diagnose an issue with low fuel pressure causing a lack of performance.

The key point is that by logging both requested and actual, you can see if the engine is doing what the ECU tells it or whether it is the ECU which is commanding a lower performance, for example limp mode.

Transmission

3^rd gear?

Thankfully, since introducing our ZF 6hp standalone looms, we have seen a steep decline in transmissions being stuck in 3^rd gear.

3^rd gear is limp mode for the transmission. Common reasons why it may be stuck in 3^rd are as follows:

• Transmission connector not fully inserted
• Missing power or ground to the transmission
• CANbus issue, either not connected to the engine ECU or resistance incorrect
• Low oil in the transmission
• Mechanical issue with the transmission

As always, we recommend checking the basics and then connecting diagnostics.

Further help

While we would like to give direct support for general issues, the sheer number of conversions being done makes this impossible. This is why we have invested in creating the most comprehensive guides and information around. We will continue to prioritise specific product support.

If you have read the above, have the skills to undertake a conversion, but just need pointing in the right direction then we recommend the following Facebook Groups:

BMW Engine Conversions & Repowers Worldwide – General conversions

M57 LandRovers – Land Rover specific group

M57 Swaps Australia – Australia-specific group but also our go-to resource for Nissan Patrols

Unfortunately we have seen a rise in people conducting engine conversions who simply do not have appropriate skills or ability for the job. If you are not confident in this, and you are unprepared to work through problems independently, then we recommend that you have the conversion conducted by a professional.