35i 'surging' under power with no error codes!

[mcbutler]

Car has 34k on it and already had one new HPFP at 18K!!!!!!

Thinking of fitting this coil kit, thoughts anyone (R.E92)

https://www.mlperformance.co.uk/collect ... system-n54

It would be a waste of money unless you are pushing 650hp+. Those coils are an upgrade for people that are going beyond the capabilities of their stock coils. You would also need MHD to run that kit as the dwell times of the coils would need changing in the DME, none of the UK dyno style tuners will be capable of doing that.

If you want more power then get MHD. With a larger intercooler and catless downpipes you would see about 410hp (£120 total). With a custom MHD tune pushing the limits of the stock turbos you could get maybe 430hp (extra £250 for a custom tune). Then if you still want more then you need to upgrade to some larger turbos (an extra £3000 including upgraded inlets and outlets) which would probably top out at 600hp on 99RON fuel.

Thanks for the info, i thought they might be overkill. Already have the larger intercooler and catless downpipes on a stage 1 from celtic.
Once my turbos get rattling I will upgrade as you mention (if we can still buy and use petrol cars then)...

[john-e89]

I don’t even want to imagine an E89 with 600hp let alone drive one….

[mcbutler]

Car has 34k on it and already had one new HPFP at 18K!!!!!!

Thinking of fitting this coil kit, thoughts anyone (R.E92)

https://www.mlperformance.co.uk/collect ... system-n54

It would be a waste of money unless you are pushing 650hp+. Those coils are an upgrade for people that are going beyond the capabilities of their stock coils. You would also need MHD to run that kit as the dwell times of the coils would need changing in the DME, none of the UK dyno style tuners will be capable of doing that.

If you want more power then get MHD. With a larger intercooler and catless downpipes you would see about 410hp (£120 total). With a custom MHD tune pushing the limits of the stock turbos you could get maybe 430hp (extra £250 for a custom tune). Then if you still want more then you need to upgrade to some larger turbos (an extra £3000 including upgraded inlets and outlets) which would probably top out at 600hp on 99RON fuel.

Can you tell me what the expected fuel rail pressure parameters are please?

[R.E92]

Car has 34k on it and already had one new HPFP at 18K!!!!!!

Thinking of fitting this coil kit, thoughts anyone (R.E92)

https://www.mlperformance.co.uk/collect ... system-n54

It would be a waste of money unless you are pushing 650hp+. Those coils are an upgrade for people that are going beyond the capabilities of their stock coils. You would also need MHD to run that kit as the dwell times of the coils would need changing in the DME, none of the UK dyno style tuners will be capable of doing that.

If you want more power then get MHD. With a larger intercooler and catless downpipes you would see about 410hp (£120 total). With a custom MHD tune pushing the limits of the stock turbos you could get maybe 430hp (extra £250 for a custom tune). Then if you still want more then you need to upgrade to some larger turbos (an extra £3000 including upgraded inlets and outlets) which would probably top out at 600hp on 99RON fuel.

Can you tell me what the expected fuel rail pressure parameters are please?

It depends heavily on the conditions. Fuel pressure should be up around 2000 PSI at full chat and 700 at normal cruising.

During a cold start the fuel pressure should jump up to 2500-3000 then settle around 2500 after until the cold start has finished.

A warm start I think would stick around 700.

Here's what my cold start fuel pressure looks like:
https://datazap.me/u/rich/cold-start-va ... data=19-20

Here is a log of some normal driving with some occasional acceleration:
https://datazap.me/u/rich/335i-v53?log=0&data=4-22-23

[mcbutler]

It would be a waste of money unless you are pushing 650hp+. Those coils are an upgrade for people that are going beyond the capabilities of their stock coils. You would also need MHD to run that kit as the dwell times of the coils would need changing in the DME, none of the UK dyno style tuners will be capable of doing that.

If you want more power then get MHD. With a larger intercooler and catless downpipes you would see about 410hp (£120 total). With a custom MHD tune pushing the limits of the stock turbos you could get maybe 430hp (extra £250 for a custom tune). Then if you still want more then you need to upgrade to some larger turbos (an extra £3000 including upgraded inlets and outlets) which would probably top out at 600hp on 99RON fuel.

Can you tell me what the expected fuel rail pressure parameters are please?

It depends heavily on the conditions. Fuel pressure should be up around 2000 PSI at full chat and 700 at normal cruising.

During a cold start the fuel pressure should jump up to 2500-3000 then settle around 2500 after until the cold start has finished.

A warm start I think would stick around 700.

Here's what my cold start fuel pressure looks like:
https://datazap.me/u/rich/cold-start-va ... data=19-20

Here is a log of some normal driving with some occasional acceleration:
https://datazap.me/u/rich/335i-v53?log=0&data=4-22-23

Thank you for the info, your second link does not appear to work but the rail - RPM chart is very useful

[R.E92]

Can you tell me what the expected fuel rail pressure parameters are please?

It depends heavily on the conditions. Fuel pressure should be up around 2000 PSI at full chat and 700 at normal cruising.

During a cold start the fuel pressure should jump up to 2500-3000 then settle around 2500 after until the cold start has finished.

A warm start I think would stick around 700.

Here's what my cold start fuel pressure looks like:
https://datazap.me/u/rich/cold-start-va ... data=19-20

Here is a log of some normal driving with some occasional acceleration:
https://datazap.me/u/rich/335i-v53?log=0&data=4-22-23

Thank you for the info, your second link does not appear to work but the rail - RPM chart is very useful

Second one should work now. I had it set to private

[mcbutler]

It depends heavily on the conditions. Fuel pressure should be up around 2000 PSI at full chat and 700 at normal cruising.

During a cold start the fuel pressure should jump up to 2500-3000 then settle around 2500 after until the cold start has finished.

A warm start I think would stick around 700.

Here's what my cold start fuel pressure looks like:
https://datazap.me/u/rich/cold-start-va ... data=19-20

Here is a log of some normal driving with some occasional acceleration:
https://datazap.me/u/rich/335i-v53?log=0&data=4-22-23

Thank you for the info, your second link does not appear to work but the rail - RPM chart is very useful

Second one should work now. I had it set to private

Excellent thank you wondering if carly can read fuel rail live data, will have a look tomorrow

[mcbutler]

OK - small but probably importnant new detail. After meeting up with phoenixboy (Grant) yesterday I notoced quite a strong smell of fuel after anohter weak hearted warm start.
I am erring towards injectors leaking - been told Indez 12 are arounf £450 each - warranty direct will love this lol
No codes though - surprisingly

Thoughts anyone

[R.E92]

You can pull your spark plugs and see if they are wet with fuel.

You can also use a borescope and feed it into the spark plug hole and see if the injector leaks fuel while the fuel pump is primed.

New injectors are about £250 each. Fitting would be 2hrs labour.

[mcbutler]

You can pull your spark plugs and see if they are wet with fuel.

You can also use a borescope and feed it into the spark plug hole and see if the injector leaks fuel while the fuel pump is primed.

New injectors are about £250 each. Fitting would be 2hrs labour.

Thanks for the idea, I have seen the index 12 injectors, mine are index 6! Considering changing them regardless to be honest.

How long after engine off would you wait to look at the plugs?

[enuff_zed]

How long after engine off would you wait to look at the plugs?

I'd think well after it's all gone cold, as the heat will evaporate any fuel on them to begin with.

[R.E92]

You can pull your spark plugs and see if they are wet with fuel.

You can also use a borescope and feed it into the spark plug hole and see if the injector leaks fuel while the fuel pump is primed.

New injectors are about £250 each. Fitting would be 2hrs labour.

Thanks for the idea, I have seen the index 12 injectors, mine are index 6! Considering changing them regardless to be honest.

How long after engine off would you wait to look at the plugs?

As quick as possible. The injectors leak while the rail is pressurised so if you wait too long the rail pressure will drop and they will stop leaking. You can search YouTube for videos showing it happen on all kinds of cars.

I had index 6 injectors on my 3 series. I changed them as a precaution as i noticed the oil had a fuelly smell during an oil change. The car ran fine but leaky injectors can be disastrous for engine wear as they can dilute the oil.

If you're keeping the car for the forseeable future it would be worth changing them regardless. You could keep an eye out for a used set on eBay, index 12s usually fetch £125 each used. You can get a full set of new ones for £1200 from deutsch parts on eBay.

[enuff_zed]

As quick as possible. The injectors leak while the rail is pressurised so if you wait too long the rail pressure will drop and they will stop leaking.

That's me told then.
I'll get back to my old carbs.

[mcbutler]

You can pull your spark plugs and see if they are wet with fuel.

You can also use a borescope and feed it into the spark plug hole and see if the injector leaks fuel while the fuel pump is primed.

New injectors are about £250 each. Fitting would be 2hrs labour.

Thanks for the idea, I have seen the index 12 injectors, mine are index 6! Considering changing them regardless to be honest.

How long after engine off would you wait to look at the plugs?

As quick as possible. The injectors leak while the rail is pressurised so if you wait too long the rail pressure will drop and they will stop leaking. You can search YouTube for videos showing it happen on all kinds of cars.

I had index 6 injectors on my 3 series. I changed them as a precaution as i noticed the oil had a fuelly smell during an oil change. The car ran fine but leaky injectors can be disastrous for engine wear as they can dilute the oil.

If you're keeping the car for the forseeable future it would be worth changing them regardless. You could keep an eye out for a used set on eBay, index 12s usually fetch £125 each used. You can get a full set of new ones for £1200 from deutsch parts on eBay.

Job for tomorrow then.

I have done a seller search on the Bay for deutsch parts, nothing found!!!

[R.E92]

Thanks for the idea, I have seen the index 12 injectors, mine are index 6! Considering changing them regardless to be honest.

How long after engine off would you wait to look at the plugs?

As quick as possible. The injectors leak while the rail is pressurised so if you wait too long the rail pressure will drop and they will stop leaking. You can search YouTube for videos showing it happen on all kinds of cars.

I had index 6 injectors on my 3 series. I changed them as a precaution as i noticed the oil had a fuelly smell during an oil change. The car ran fine but leaky injectors can be disastrous for engine wear as they can dilute the oil.

If you're keeping the car for the forseeable future it would be worth changing them regardless. You could keep an eye out for a used set on eBay, index 12s usually fetch £125 each used. You can get a full set of new ones for £1200 from deutsch parts on eBay.

Job for tomorrow then.

I have done a seller search on the Bay for deutsch parts, nothing found!!!

https://www.ebay.co.uk/itm/BMW-Fuel-Inj ... 3674093502

You might be able to get them from somewhere closer. Try lllparts
https://www.lllparts.co.uk/en/