Ok so I just recently just replaced all fuel injectors, coils, and spark plugs, but I keep getting misfire in all 6 I’m thinking it’s my ecu what can I do any help will be appreciated thank you

Morning Nick

When you replaced the Injectors were they (a) Correct for your car and (b) correctly registered to the car ? What Diagnostic program are you using ?

Dave

46 minutes ago, Greydog said:

Morning Nick

When you replaced the Injectors were they (a) Correct for your car and (b) correctly registered to the car ? What Diagnostic program are you using ?

Dave

How do I do the registration an ista+

Hi Nick

How practised are you with ISTA + ? First you need the values from the Injector bodies (if you haven't written them down already) If you don't have them it looks like you will be taking them out again !!

Rather than a long post on ISTA try this link it will help https://www.youtube.com/watch?v=ErTLV0NqIOM

Dave

2 hours ago, Greydog said:

Hi Nick

How practised are you with ISTA + ? First you need the values from the Injector bodies (if you haven't written them down already) If you don't have them it looks like you will be taking them out again !!

Rather than a long post on ISTA try this link it will help https://www.youtube.com/watch?v=ErTLV0NqIOM

Dave

Do I have to do that with a 2006 x3

Hi Nick

What engine does your car have ? you say M54 but around the middle of 2006 BMW introduced the N52 engine Have you checked? N52 engines will need injectors registering if it's late M54 it may or may not

Are the injectors new? Are the injectors the correct volume (should be 525cc If my old brain is working) ? The adaptions stored in the ECU may not match what you have replaced the originals with, they may need resetting a check with ISTA wont hurt

As you are getting misfiring on all 6 something is not right, is the injector rail and injectors seated correctly are all the injector seals OK I have seen plenty damaged on reassembly

Dave

Yea it’s the m54 engine an every thing is new im going to do a ista+ run later today day an check it out thanks for all ur help brother

On 2/20/2026 at 10:26 AM, Greydog said:

Hi Nick

What engine does your car have ? you say M54 but around the middle of 2006 BMW introduced the N52 engine Have you checked? N52 engines will need injectors registering if it's late M54 it may or may not

Are the injectors new? Are the injectors the correct volume (should be 525cc If my old brain is working) ? The adaptions stored in the ECU may not match what you have replaced the originals with, they may need resetting a check with ISTA wont hurt

As you are getting misfiring on all 6 something is not right, is the injector rail and injectors seated correctly are all the injector seals OK I have seen plenty damaged on reassembly

Dave

Ok there all the same numbers 1439800 so I would put 389 in ista+ an it is the m54 engine

Morning Nick

Sorry don't recognise that number looks more like a Batch number to me particularly as you have the same number on all injectors, there is normally a flowrate number which I would expect to start with a 5 ? The only other thought is that the Injectors that you have are not correct ? Are they possibly EU5 or EU6. If they are correct then it is back tracking through the work done to ensure there are no leaks, damaged seals or wiring.

What information is ISTA asking for it normally is quite specific

Dave

2 hours ago, Greydog said:

Morning Nick

Sorry don't recognise that number looks more like a Batch number to me particularly as you have the same number on all injectors, there is normally a flowrate number which I would expect to start with a 5 ? The only other thought is that the Injectors that you have are not correct ? Are they possibly EU5 or EU6. If they are correct then it is back tracking through the work done to ensure there are no leaks, damaged seals or wiring.

What information is ISTA asking for it normally is quite specific

Dave

Ista dose not have a opinion to do the injectors for a m54 I guess

Hi Nick

From ISTA

Steps to Check Injectors

1. Connect ISTA: Use a compatible diagnostic interface to connect ISTA to the vehicle's OBD-II port.

2. Select Vehicle: Enter the vehicle identification number (VIN) or select the model manually to ensure accurate diagnostics.

3. Access Fuel Injector Data:

   • Navigate to the engine control module (ECM) section.

   • Look for the fuel injector diagnostics option.

4. Run Tests:

   • Perform a functional test to check the operation of each injector.

   • Monitor injector pulse width and fuel trim values to assess performance.

5. Review Fault Codes: Check for any stored fault codes related to the fuel injectors. This can indicate issues such as misfires or electrical problems.

Additional Considerations

• Injector Replacement: If issues are detected, consider replacing injectors in sets for balanced performance.

• Safety Precautions: Always relieve fuel system pressure before working on injectors to prevent spills.

Using ISTA effectively can help diagnose and maintain the performance of the M54 engine's fuel injectors.

Does this help

Dave

6 hours ago, Greydog said:

Hi Nick

From ISTA

Steps to Check Injectors

1. Connect ISTA: Use a compatible diagnostic interface to connect ISTA to the vehicle's OBD-II port.

2. Select Vehicle: Enter the vehicle identification number (VIN) or select the model manually to ensure accurate diagnostics.

3. Access Fuel Injector Data:

   • Navigate to the engine control module (ECM) section.

   • Look for the fuel injector diagnostics option.

4. Run Tests:

   • Perform a functional test to check the operation of each injector.

   • Monitor injector pulse width and fuel trim values to assess performance.

5. Review Fault Codes: Check for any stored fault codes related to the fuel injectors. This can indicate issues such as misfires or electrical problems.

Additional Considerations

• Injector Replacement: If issues are detected, consider replacing injectors in sets for balanced performance.

• Safety Precautions: Always relieve fuel system pressure before working on injectors to prevent spills.

Using ISTA effectively can help diagnose and maintain the performance of the M54 engine's fuel injectors.

Does this help

Dave

Yea when I run ista+ there’s absolutely nothing with fuel injectors in that system

Morning Nick

Then I am at a loss here, my assumption was the DME has retained the settings for your old Injectors which is causing the misfires. So if there are no leaks and the Injectors are correct (my contact in BMW has seen instances where Euro 5 or Euro 6 Injectors were fitted) but without diagnostics ???

Just been next door (7.00am) and asked my neighbour if I could run my copy of ISTA on his E46 M54 engine and can find the DME and Injectors no problem ran a smooth running check (Happy to say he has no issues) also ran INPA and could get the same results took 20mins but needed to confirm what ISTA was saying. So really confused now? I am still convinced that ISTA should be able to sort it if only by pointing to the retained faults

Dave

As an after thought have you tried the Pelican Parts website ? they have a lot of great articles with pictures that may help