MI16 wiring help - No spark

[Omorgan 1 1 Cars]

No worries I'll get on that when I get home. Thanks for explaining it all to me. 

[SRDT 175]

Don't waste your time looking for the right fuse box or using another relay, the setup from the 405 is perfectly fine.

 

A bit more info:

http://www.ckc.dk/pubs/XU9J4-Controle_Reglage_Diagnostic.pdf

https://www.bxclub.cz/files/elektro/Fuel.pdf

[Omorgan 1 1 Cars]

Spot on those are great thank you.  As @petert said, I ran the fuel pump power from the fuse and wire 76 and installed the relay that @DamirGTI recommended into the green relay holder, left the brown disconnected and the thing fired up and ran. Thank you all for your advice. I can't yet leave it running for more than a few seconds because I haven't set up the cooling system and I haven't made up a heatsink for the AMP yet + I need to make an exhaust longer than just the manifold. Once this is done I'll see if its all working properly. 

 

Cheers, Owen.

[Omorgan 1 1 Cars]

On 5/1/2024 at 2:38 PM, SRDT said:

It's a dual output relay on the schematics but pin 4 is unused so a regular relay should do.

 

Here is the ECU and fuel pump relay setup from a 35 pin 405 in more detail, a loom from a BX 16 Valve or 309 GTI16 may vary a bit regarding relay type and location.

Hi guys, I'm just after a bit more advice please. I now have spark but I've made a mistake while bridging the injection relay and have melted the insulation on wire #32 meaning my fuel injectors at being inconsistent, shown on the diagram above. I'd like to replace it but the diagram only states that wire 32 goes to ground and to AC supply so I'm guessing the coil. Just hoping someone would be able to tell me where the yellow wire goes please. 

 

 

[SRDT 175]

54 minutes ago, Omorgan said:

the diagram only states that wire 32 goes to ground and to AC supply

 

It doesn't go to ground, U4 with the arrow means that it's for testing.

It's +12V ACC from the ignition switch, not sure how it was spliced on your car.

[Omorgan 1 1 Cars]

Amazing thanks mate I'll have a look 

[Omorgan 1 1 Cars]

Hi again guys. Really sorry for all the questions but this swap is kicking my ass. I now have an issue with the injection system not wanting to inject. I have spark. I have the relay in place for the fuel pump and have fuel pressure, I can hear it prime when cranking. I have removed all the injectors and cleaned them with Injector cleaner and 12v to flush them and they all spray nicely. 

 

When I crank the car with all the injectors plugged in and the injection relay disconnected, they don't spray, but one or two buzz when I turn ignition off, spraying a small amount at the end, visable in the video attached. 

 

When I crank the car with one injector disconnected, and the injection relay disconnected again, the other 3 injectors open and spray and continue to after I stop cranking until I turn ignition off, making a strange buzzing sound. 

 

When I connect the injection relay or bridge it and crank the car, there's nothing coming out the injectors. 

 

The voltage at the injectors is common at 0.95V on ignition 2 (ecu on). They all go to 4V when cranking. 

 

Does anyone maybe have any ideas please? Perhaps I'm being an idiot 

 

Cheers. 

 

https://youtube.com/shorts/ofG6wJygW88?si=fr1B3XeWSGP7Tu31

Edited May 7 by Omorgan

[welshpug 1,657]

injectors should be getting 12v.

[Omorgan 1 1 Cars]

I just had another play. With ignition on and the injector relay unplugged. All the injectors get 12V. Plugging each one in on its own makes them buzz and inject a very small amount of fuel. With more than one connected up they stop injecting 

[Omorgan 1 1 Cars]

Hi guys, I'm now struggling from a new issue that I've been struggling to diagnose, but think it might be spark so have left it in this thread. The only way I can reliably rev the car is by spamming the throttle and it won't rev past a certain point before bogging. If I hold the throttle, it sounds like the revs hold almost like a golf R with launch control. I've changed the AFM and unplugged the SAD and TPS but it didn't change anything. I've checked and re-timed the car 3 times and all looks good.

 

https://youtube.com/shorts/PN5uid25YuA?si=RePhpqHxOnime3Hf

 

You can see what I mean above with volume turned up. 

 

Any help would be appreciated, thanks. 

[SRDT 175]

Are you using a "made in germany" blue ignition module ? Some Motronic engines won't work with the newer black modules.

[Omorgan 1 1 Cars]

Yes mate I got one from Miles at pug Racing near me. The proper blue top one. I was reckoning it might be the module but wanted someone else's advice. Interestingly this evening, from cold I did the same thing, planted my foot and it made the launch control sound and then revved right up once, perhaps suggesting it's temperature related

[DamirGTI 342]

Youtube says : private video , i cannot open it ..

 

Dirty/clogged injectors can cause similar issues , but a little bit different at least from what i understood from you're description .

 

At idle , when you press the acc. pedal sharpish and let off it'll bog down/sputter ie. it wont respond "cleanly" shifting the revs up accordingly to the acc. pedal application or none at all ... and when you try to do the same but pressing the acc. pedal slowly/gradually then it revs up "cleanly" without bogging down/sputtering  - classic sign of dirty/clogged injectors . 

 

D

[Tom Fenton 1,541]

How old is the petrol, I have had similar with old stale fuel.

[Omorgan 1 1 Cars]

2 hours ago, DamirGTI said:

Youtube says : private video , i cannot open it ..

 

Dirty/clogged injectors can cause similar issues , but a little bit different at least from what i understood from you're description .

 

At idle , when you press the acc. pedal sharpish and let off it'll bog down/sputter ie. it wont respond "cleanly" shifting the revs up accordingly to the acc. pedal application or none at all ... and when you try to do the same but pressing the acc. pedal slowly/gradually then it revs up "cleanly" without bogging down/sputtering  - classic sign of dirty/clogged injectors . 

 

D

Hello mate, I've changed the link, it might work now. 

 

 

 

I've tested and cleaned my injectors for a previous issue I was shaping and I'm happy they're okay. The fuel pump is new and flows a lot. I understand what you mean about the revving slow and fast but I don't believe it is the same issue necessarily. It seems more like something hits a brick wall and will now allow it to rev higher than roughly 2-3K (I don't have a tacho I'm not too sure) 

 

I'll take a look at them again though to be sure. Thanks 

 

[Omorgan 1 1 Cars]

5 minutes ago, Tom Fenton said:

How old is the petrol, I have had similar with old stale fuel.

The fuel is brand new so I don't think it should be that but thank you for the idea. 

[Omorgan 1 1 Cars]

This is an update of trying to diagnose this issue. I notice the car revvs fine when I move the AFM arm and the throttle butterfly. Does this suggest a dead AFM to anyone?