Hi, I have a RWD converted Mk2 Scirocco running a 1.8T AGU engine controlled by an Emerald K6+ standalone ecu. I've been building the car the last couple years and its now at the stage of the final build up and getting it running after paint etc. However I just can't get the damn thing to run!! Prior to paint it ran quite well, I even had it setup on the dyno at very low boost just to get it slightly more fine tuned and it made 250hp at the rear wheels at roughly 1bar of boost - great! Couple weeks after the dyno run in it developed a bit of a missfire, it then refused to start up, at this stage I pulled the plugs on it and they were pretty sooty and covered in fuel. Tried in some new plugs and it ran fine again. Since then it has never really been driven and was subsequently pulled apart for paint. Now the engine is back in, fluids in, loom all plugged in etc and it just will not start! It fired ever so slightly a couple times but never came to an idle, I've tried multiple sets of plugs on it, and every time I try to start it they get soaked in fuel. I've pulled each coilpack and tested for spark and yes there is a good spark on all 4! So there seems to be fuel, there seems to be spark, maybe the timing is out... so pulled the cam cover off last night, cam timing is spot on with 16 links between the two cam notches with the far left link slightly offset, with the cam at TDC the crank pulley timing mark lines up spot on too. Pulled the cam sensor off to check the cam trigger wheel wasn't chewed up and it looks pretty much brand new. Really scratching my head with this one and running out of ideas quick! Any suggestions welcome! Thank you
I will check this tonight and see what it does! I was also thinking to unplug the fuel pump relay, spray some brake cleaner into the intake and crank it over to see if it runs off the brake cleaner or not, if it does then I guess the spark can be ruled out and the issue is fuelling related.
As far as I'm aware the emerald is set to do an initial injector prime the moment it detects crank signal to basically wet the inlet walls to aid cold start The Initial injector prime 2D table at the top of this screen dictates how long (in mS) the initial injection pulse is. This function is triggered the moment the ECU detects and locks onto the selected trigger pattern, via the crank sensor. This function has a big influence on how fast the engine starts. With no injector prime, it can take a number of engine revolutions and injection events to fully wet the inlet port so there may be a delay before the fuelling reaches the required ratio for the engine to fire. My initial inj prime is currently set to 50ms. I'm wondering if this intial prime is soaking (and subsequently fouling (?!)) the plugs before it has even attempted to ignite the fuel - just thinking out loud really
yep thats also a plan. my thoughts were maybe sticky injector(s) or maybe fuel pressure is too high for whatever reason. would be odd for something like that to happen though but you never know. a friend of mine had all 6 injectors in his v6 fail somewhere between engine being yoinked out of the running donor and plonked in his car
Update on this, with the fuel pump relay unplugged and some brake cleaner sprayed into the intake, the car will start and run absolutely fine for a few seconds until the brake cleaner is burned. I have a stack dash that gives me fuel pressure on crank, this is reading around 60ish PSI on crank - which would be correct as the fuel pressure regulator is a 4 bar one (the map is also for 4 bar just to be clear) The injectors were brand new genuine Bosch 550cc's at the time of piecing together the engine together for paint etc, so whilst they have only maybe covered no more than 50 miles (dyno miles) they have sat around quite a while, I'd still be surprised if they were failing however!
Yeah unlikely to be that tbh. Maybe pull the rail and see if it sprays with just fuel relay bridged, then when priming, and then when cranking
Pulled the rail yesterday, and filmed the injector spray during prime, and crank Turn key and pump primes, nothing from injectors as expected... Turn key again to commence cranking, there is a small pulse where all 4 injectors spray at the same time which I'm assuming is the initial 50ms inj prime setting, then the injectors start firing sequentially, in the firing order 1-2-3-4, 1-2-3-4 and so on so forth. I know the usual firing order for a 1.8T is 1-3-4-2 but I'm not sure if the Emerald has been setup to fire 1-2-3-4 instead, I'll need to investigate that. Not really sure how much or how little fuel they should be spraying also, its hard to tell if the spray pattern is healthy or not but all 4 spray something anyway!
Sounds good apart from the spray order thing, hopefully an easy fix I guess? If nothing else you could just swap the plugs to injectors till it's right May be worth checking the injector wiring back to ECU to make sure that's all good, and if you can see if that's something you can set in the map. I'd assume injector spray would.be linked directly to spark firing order... We know firing order is ok since it runs on brake cleaner
I'll need to have a dig through the Emerald screens to see how its been setup. But something must not be right if its not starting and plugs are getting soaked in fuel. Either the injectors are spraying at the wrong time on the wrong cylinders, the spray pattern is dodgy or the pressure at the injectors is not right. I do have 4 spare injectors of the same spec I could try however the 4 that are on their just now are new-ish genuines!
You asked this on facebook and Darren Francis from VW E - Emerald dealer gave a few suggestions. With these things, you need to trace the last thing you did before the problem. The map cannot undo itself and the wiring will not just failed if you are confident with the wiring integrity. Needs maybe a more experienced eye on it.
Small update on this. I've found I'm not getting 12v at the injectors with ignition switched on. I've traced back the ce1 -> 1.8T loom I made a fair while back and seems my injector live feed is from fat red N spade - red/pur injector feed, is this right @rubjonny ? Any reason why my N spade is dead with ignition on? When I jumped spade N with perm 12v the car fired up and then cut out shortly after (Think this is map related, the injection corrections shoots right down from 77% to 0% and then it cuts out)
Apart from the firing order seeming very odd a lot of this could be crank sensor as said above. Ours would start, run for a few seconds and then cut out, it was the crank sensor.
So N is fed by the fuel relay in slot 2, I assume you wired your emerald to trigger the relay and you would be using a 67/80/167 in there
Yes, I am using slot 2 of the ce1 fusebox, can't remember exactly which relay I am using however if I switch ignition on the pump is earth triggered to prime by the emerald (pin 20 iirc)
ok yeah so all sounds good, if you probe injectors while its priming you should see 12v and also voltage while cranking as well
hmmm, I'll need to check. Basically with ignition on the N spade reads 0v, and thus my injector red/pur feed has 0v
yeah you only see power at N while fuel relay is energised, if you want to verify more easily you can swap out the relay for a 17/18/100 relay that will just go live with ignition regardless of what the ECU wants
So with my current setup, as long as the fuel pump is running (relay activated) the injectors should have 12v? So if I switch on ignition and the fuel pump primes for 5 secs say, then stops, I walk round to the front of the car (ign still on) and check voltage across injectors it should be 0v? Until I start cranking it over (fuel pump relay energised again) where they would then read 12v?
