[LPG2CV]

The purpose of the FP prime, is really a purge of air, and hot fuel from the system back to the tank. Depending on how good the sytem is, will depend on how long the purge needs to be. It's useful that the injector prime follows the purge. Generally, it only need be one tenth of a second after.

[Shalmaneser]

Well she wants to start! Got some encouraging noises but couldn't quite get there. refitted the OE ECU and marveled at how easily it sprung to life! definitely smelling a lot of fuel though but i guess I need to keep bumping up the the cranking enrichment until it springs to life for a second or two?

[LPG2CV]

Try turning the ignition key on, let it prime, the turn the key off, then on again to let it prime again. In effect, priming twice. If that gives a better result, then you need more priming for the temperature you are at.

And don't forget to keep an eye on the VE table when cranking/idling. Enrichment is a multiplier of the current VE value. If the VE is low, then the enrichment will be low.You can give it a small amoutn of pedal, but to much may bring you into flood clear, and you will get no fuel.

We could probably do with looking at a log of it cranking, along with the tune the log was taken with.

[Shalmaneser]

Thought I'd turn my attention to the ICV as I've been ignoring it since it makes scary noises when I connect it up. But I need to pick this particular scab, so I disconnected the ICV and shot a quick vid of it with the OE ECU and with Speeduino:

Anyway can't see how to embed a video clip so here's a link:

https://youtu.be/SB7iU1RDZcg

[Shalmaneser]

Anyway here are a couple of logs and the tune - having looked at the logs I think the spark is too advanced at idle @15deg - does this sound too much? Doesn't run for long and sounds like sh*t but something is happening!

[LPG2CV]

From the log, as soon as you start cranking the gammae drops! Looking at the tune, there are low VE values in the top left column of the table. This is just to help start up rather than idle.

So try changing the VE values of the top five cells of the first column to match the MAP bin values. The rationale behind this is that any enrichment is a percentage multiplier of the current VE value. So, with this in mind, once the engine fires up, it move out of cranking and into ASE (WUE is applied all the time). So then we are looking at the VE value of where the engine is trying to idle. The ASE values will apply to this cell in the VE table.

Tuning in the first instance appears a bit backwards, in that the engine needs to get to normal operating temperature to enable the tuner to set the correct idle VE value. Once you set that value, then appropriate warm up enrichments can be applied dependening on engine temperature.

[Shalmaneser]

She starts! And runs! Amazing really.

Confession time - it was due to a really stupid/lazy error. On the wiring diagram the injectors are down as injector 1, injector 2... and coil 1, coil 2... I assumed these aligned to cylinder numbers. Wrong! They are related to firing order! So while firing order in a flat 6 is 1-6-2-4-3-5 the firing order of the labelled injectors is 1-2-3-4-5-6. Makes sense (kinda). Anyway I only checked cylinders 1 and 4 (closest to the front of the engine) and those ones lined up with the numbers. So cylinders 6+3 and 2+5 were back to front. I does make the spreadsheet neater.

Lesson learned - check everything properly, and don't assume.

Some real head scratching to figure that out but it's there in the wiring diagram in black and white, just lost in a load of lines. When I switched that it sprang to life pretty easily. Everything works pretty nicely really.

Had a small emergency when the coil ground started smoking on the ECU connector PCB, clearly that is undersized for the current.

Next question is to figure out how to run the power. The OE ECU has a permanent high current live coming in which is switched internally from a signal wire. Need to replicate that functionality, I think Pazi has done something similar in some of his BMW plug n play boards.

I'm going to work on a PCB layout for the current connections as it's just a mess of wires at the moment and would be lovely to neaten it up, plus hopefully it'll be a good learning experience!

[LPG2CV]

Well done on starting.

Had a small emergency when the coil ground started smoking on the ECU connector PCB, clearly that is undersized for the current.

Please elaberate on this. This does not sound correct. How do you have this wired?

[Shalmaneser]

Well done on starting.

Had a small emergency when the coil ground started smoking on the ECU connector PCB, clearly that is undersized for the current.

Please elaberate on this. This does not sound correct. How do you have this wired?

The ECU has a specific pin for spark ignitor ground (as the motor uses dumb coils). the trace on the PCB adaptor started smoking after a bit of running so I assume the trace wasn't up to the amperage? The wiring diagram specifies this as a 2.5mm^2 cable to carry this current which I think is about 20 Amps? I guess the trace on the adaptor wasn't up to the job...
It's the thickest wire in the ECU loom, everything else is max 1.5mm

[jonbill]

I reckon coil ground goes to the head or block, not the Speeduino.