350i New Owner

[Penelope Stopit]

KKson said:

What we need here is input from Penelope.......

Ok KK, your wish is my command

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There is a possibility that the injection relay fitted is incorrect (of the wrong terminal configuration)

See below diagram that I posted to a topic in the past, it shows the circuit clearly

Earlier topic is here https://www.pistonheads.com/gassing/topic.asp?h=0&...

Have included the information from the earlier topic as it may help

Enjoy. Click image and click again to go full size

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Penelope Stopit said:

I recall that someone posted in the past stating that the pump didn't prime with ignition on, there is only one way the pump could possibly prime with ignition on and that would be from a ECU pin 20 positive output when switching the ignition on, I thought ECU pin 20 received an input from the airflow meter contact......I could be wrong but.....

Take a look at the diagram I've drawn for the Pektron circuit and you will see that the fuel pump relay is operated when turning the key to the crank position and also when the airflow meter contact switches in

If you are 100% sure that your pump primed when switching the ignition on, there is the possibility that a incorrectly wired Pektron was causing it or a relay fitted in the wrong place, a faulty diode inside the Pektron could also cause this

You could do with someone verifying that an identical cars fuel pump does or doesn't prime when the ignition is turned on

Edited by Penelope Stopit on Sunday 15th December 10:46

[Penelope Stopit]

XXXXXXXXXXXXXXXXXXX NOTE XXXXXXXXXXXXXXXXXXXXXXXXX

The above injection relay will very likely have 2 x terminal 87s

Below diagram shows relay numbers if needed

[CJD2005]

The fuel pump primes when cranking on mine, and pressure is great. Cold start injector not working also

[CJD2005]

CJD2005 said:

CJD2005 said:

The fuel pump primes when cranking on mine, and pressure is great. Cold start injector not working also

the left bank of 3 relays pektron down over I believe are the ones in question, looking at the wiring configuration underneath

[Penelope Stopit]

Have a hunch that you've misunderstood the above information

Only included information from a topic from the past as thought it may be of some help

CJD2005 said:

So.... Tried the damp start, no joy... Injectors are not opening, however if I stick 3v across them I can hear them open and close, so is not getting a signal.. I've tested most things, I'm getting 12v to the injector plugs before cranking. Resistor pack tests out OK.

However as mentioned previously I'm still getting 12v to pin 10 on the ecu plug when ignition off, and 0v when ignition on.??

I'm looking to get the ecu checked out as I don't know what state its currently in.. Am I missing something simple, quite happy to have ecu checked for piece of mind..

Is pointing to an incorrect injection relay or its wiring, suggest check relay first

See below images

This first images are of incorrect relays (note they have a terminal 87a rather than 2 x terminal 87s or 87 and 87b)





This second image shows the correct type of relay



No supply at ECU Pin 10 with ignition on means...

No worky worky and no Xmas Turkey

Edited by Penelope Stopit on Sunday 15th December 12:19

[CJD2005]

Thanks for all the info, apologies being new to this its taking time to sink in, will source a new relay, the injection relay I take it is the same as the relay labelled "main relay" assume these are easily available?? Many thanks again

[CJD2005]

[Penelope Stopit]

CJD2005 said:

Above relay shows diode in series with relay coil

Need to order relay without diode

[Penelope Stopit]

https://www.autoelectricsupplies.co.uk/product/172...

[CJD2005]

Great thanks so much...

[mrzigazaga]

The SD1 site that was posted is a wealth of knowledge too
http://www.vintagemodelairplane.com/pages/Download...

[CJD2005]

New relay ordered, will let you know how it goes.. Thanks all..

[mrzigazaga]

My cold start injector went to ground, a lot of people say you do not need them but you do, that is why it is on there!..So rather than try to trace the wires into the loom I decided to convert a cigarette lighter socket lamp and cut the wires and connected it to a spare CSI plug...now I put it in to the socket, turn the key ...3 rotations of the engine and she bursts into life, before that without the CSI...even on a warm day she took an absolute age to start...some really need that extra squirt of fuel to kick into life...

Bad starting pre modified Cold Start Injector
https://www.youtube.com/watch?v=YvL4sn1qS5M
(Excuse my language)

After:
https://www.youtube.com/watch?v=qQUTblbqmvA&li...

[adam quantrill]

A better way to test the injectors are being driven from the ECU:

1. Ignition on.
2. From under the bonnet, rotate the throttle butterfly fully, and quickly by hand.
3. You should hear the injectors "click".

THis is the ECU fuel enrichment kicking in on full throttle.

Yes the fuel pump primes when cranking or the air meter is puched open (by air).
So my usual starting procedure from cold is to: crank for 1-2 seconds. Wait 5-10 seconds, leave ignition on. Crank again, it usually goes on the first whirr.

THis saves much load on the battery and starter motor.

[KelvinatorNZ]

mrzigazaga said:

My cold start injector went to ground, a lot of people say you do not need them but you do, that is why it is on there!..So rather than try to trace the wires into the loom I decided to convert a cigarette lighter socket lamp and cut the wires and connected it to a spare CSI plug...now I put it in to the socket, turn the key ...3 rotations of the engine and she bursts into life, before that without the CSI...even on a warm day she took an absolute age to start...some really need that extra squirt of fuel to kick into life...

Bad starting pre modified Cold Start Injector
https://www.youtube.com/watch?v=YvL4sn1qS5M
(Excuse my language)

After:
https://www.youtube.com/watch?v=qQUTblbqmvA&li...

Interesting, I wonder what is different from the Vitesse config? Its well known in the SD1 circles that unless you live under a constant sheet of ice the CSI is rubbish, not needed and best removed lest it begins to leak as so many do. I disconnected and never ran mine on my first car with standard flapper as I saw no difference hot or cold, and it was removed on the other two due to running aftermarket ECUs.

The CSI should not be doing anything (nor is it needed) for a hot day or hot start as the thermotime switch contacts are fully open at any coolant temp over 35c, so the injector will not fire.

I believe you have a bandaid for another issue with your injection system by manually firing the CSI. Have you smoke tested your intake and breather system for air leaks? Is your over-run valve adjusted correctly?

[KelvinatorNZ]

adam quantrill said:

A better way to test the injectors are being driven from the ECU:

1. Ignition on.
2. From under the bonnet, rotate the throttle butterfly fully, and quickly by hand.
3. You should hear the injectors "click".

THis is the ECU fuel enrichment kicking in on full throttle.

Yes the fuel pump primes when cranking or the air meter is puched open (by air).
So my usual starting procedure from cold is to: crank for 1-2 seconds. Wait 5-10 seconds, leave ignition on. Crank again, it usually goes on the first whirr.

THis saves much load on the battery and starter motor.

That test will only work if the throttle position sensor is working and correctly adjusted, this can be measured with a multimeter checking for certain voltage when throttle is open and closed. IIRC should be about 0.3v closed, 4.7v open.

[KKson]

I'm on to my third Wedge and cold start injector has been disconnected on all, without issues. I reckon Marks starting issue lies elsewhere but using the CSI to prime the system at least gets the car started. The idea of temporarily wiring the CSI to the lighter socket does however concern me somewhat.

[mrzigazaga]

KelvinatorNZ said:

mrzigazaga said:

My cold start injector went to ground, a lot of people say you do not need them but you do, that is why it is on there!..So rather than try to trace the wires into the loom I decided to convert a cigarette lighter socket lamp and cut the wires and connected it to a spare CSI plug...now I put it in to the socket, turn the key ...3 rotations of the engine and she bursts into life, before that without the CSI...even on a warm day she took an absolute age to start...some really need that extra squirt of fuel to kick into life...

Bad starting pre modified Cold Start Injector
https://www.youtube.com/watch?v=YvL4sn1qS5M
(Excuse my language)

After:
https://www.youtube.com/watch?v=qQUTblbqmvA&li...

Interesting, I wonder what is different from the Vitesse config? Its well known in the SD1 circles that unless you live under a constant sheet of ice the CSI is rubbish, not needed and best removed lest it begins to leak as so many do. I disconnected and never ran mine on my first car with standard flapper as I saw no difference hot or cold, and it was removed on the other two due to running aftermarket ECUs.

The CSI should not be doing anything (nor is it needed) for a hot day or hot start as the thermotime switch contacts are fully open at any coolant temp over 35c, so the injector will not fire.

I believe you have a bandaid for another issue with your injection system by manually firing the CSI. Have you smoke tested your intake and breather system for air leaks? Is your over-run valve adjusted correctly?

Hi Kelvin.

You are correct, there is an issue somewhere, my guess is an air leak as I need to pull the plenum off to replace the fuel hoses on the fuel rail...I noticed the other day that the vacuum on the plenum to fuel pressure regulator is a bit naff..I used blue hylomar last time but was going to redo with wynns gasket seal...the Thermotime switch and coolant temperature sender were checked for their resistance etc, all good, the cold start was found to be going to ground through methodical testing from ecu to component..and the 12v from the socket is enough to trigger the injector for a couple of seconds, mine just needs a bit of a kick start, especially if it is a bit of a cold morning, however it does need it sometimes on a normal warm-ish day, so definitely an underlying issue somewhere...

I will get to the bottom of it...Dont worry Keith, it is okay, it is plugged in pre-ignition...cranked on, then removed..it does not get hot and it is fused so ..all good..

[mk1fan]

CJD2005 said:

So.... Tried the damp start, no joy...

If the car didn't run when you sprayed 'damp start' into the plenum then you have no spark. You may have no fuel as well, but the engine should run on 'damp start'. Did you disconnect the plenum hose and spray it directly in?

[Penelope Stopit]

CJD2005 said:

New relay ordered, will let you know how it goes.. Thanks all..

Ok then

The baby could be up and running once the supply to ECU Pin 10 is sorted