9a vs ACE 2,016v

[UrS4boy]

The trigger signal, would that come from the hall sensor?

For a 3B it would come from the J220 ECU at Pin T55/1, as per the diagram. For an ACE, I have no clue.

3B ECU connector pin-out (for reference only):

[fish]

Ground and positive work fine, do we know if the hall sensor signal up to the module plug is positive or negative?

[fish]

New problem. Pulled the plugs (only checked spark before with a spare plug) they are all bone dry... Fuel is coming up to meterhead anyway and i loosened all the banjos to each injector and all let fuel out on top of meterhead. Somehow its not getting to the injectors from there. Pulled plug of the tempsensor but nothing happened. Really doing my head in this.

[newsh]

If it's like S2 then injectors will not run if hall signal is outside of timing window. Time to check timing, maybe worn dizzy gear or crank pulley has moved.

https://www.picoauto.com/library/case-studies/audi-s2-intermittent-and-progressive-failure-to-start

[fish]

If it's like S2 then injectors will not run if hall signal is outside of timing window. Time to check timing, maybe worn dizzy gear or crank pulley has moved.

https://www.picoauto.com/library/cas...ilure-to-start

Don,t know if it works the same as an S2 as it has a mechanical injectionsystem...

[newsh]

Well , fuel pump wont run if timing is out.

Check the timing anyway and check the dizzy for play.

[fish]

Well , fuel pump wont run if timing is out.

Check the timing anyway and check the dizzy for play.

If the timing was out, would it not spark at all then? Car ran fine thursday evening and them not at all friday morning.

[newsh]

It only needs one pulse from the dizzy at the correct time and it will start and keep running. Then if the timing then moves, just a bit, and you switch off, it won't restart.

[newsh]

Not hard to check the timing is it and it would rule it out if it's all ok. Here's a quote from that link above..

Both of these allowed the engine to start but not reliably as the flutter in the distributor drive train meant that the start position was not always with the zero crossing inside the Hall pulse. Any further either way prevented it from starting completely.

Eventually we came to the conclusion that the Hall negative pulse acts as a "gate" during the start sequence and only allows the ECU to act on the TDC information when the zero crossing occurs when it is low. Testing has revealed that this is very critical and that if the distributor backlash range is as much as 0.1 of a millisecond outside the Hall pulse it won’t start reliably.

[JariP]

ACE ignition uses only the hall sender in distributor for the timing. There's no pins on the flywheel and no senders reading the flywheel teeth. Distributor runs directly off the exhaust cam end, so there's not many parts to wrong. It can have some weird faults though, for example mine stopped running after the lambda probe died. Have you tried disconnecting the lambda probe?

KE-motronic has a fuel cut off feature for the overrun, it uses the pressure differential regulator, so it can cut the fuel out.

Here's the factory manual for 6A/ACE KE-motronic.

[fish]

ACE ignition uses only the hall sender in distributor for the timing. There's no pins on the flywheel and no senders reading the flywheel teeth. Distributor runs directly off the exhaust cam end, so there's not many parts to wrong. It can have some weird faults though, for example mine stopped running after the lambda probe died. Have you tried disconnecting the lambda probe?

KE-motronic has a fuel cut off feature for the overrun, it uses the pressure differential regulator, so it can cut the fuel out.

Here's the factory manual for 6A/ACE KE-motronic.

Thanks for that mate. When you say fuel cut off valve for the overrun, do you mean while it is cranking on the key before it starts? Does it cut the fuel off while i turn the key? Did you loose your spark when your lambda went out?

I was thinking that it didnt run the pump until it sparkad, and with no spark it would not just full the cylinders with fuel. So i was sort of thinking it might be the coil or power output stage for the coil.. When i say thinking i mean i was hoping

[newsh]

Well it was a good theory (I'd still check the timing marks, just front pulley and dizzy marks)

Anyway according to that manual it looks like you can use Vagcom on it.

[JariP]

I don't think It should cut the fuel when starting. The fuel cut off happens when your lift off your foot from the gas pedal on gear so there's no fuel injected in to the engine when decelerating. I just mentioned it because even it is a mechanical injection system, it can cut the fuel if the pressure differential regulator is getting a wrong or no signal from the ecu.

I don't know if it lost spark when I had the lambda probe problem, I found disconnecting the lambda probe helped before I started to check everything else. But it didn't even try to start, so either spark or fuel or both where off completely.

[fish]

Well it was a good theory (I'd still check the timing marks, just front pulley and dizzy marks)

Anyway according to that manual it looks like you can use Vagcom on it.

I will try to check the markings tomorrow.

Would VAGCOM work instead of the vag1551 tool? If i used the 2+2 adaptercables?

[newsh]

Yes I think Vagcom will work with the 2+2