Practical Standalone Tuning: Step 5: initial Startup
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Step 5: initial Startup
08.10
| 00:00 | - In the next step of our process, we finally get to try starting the engine for the first time and I know that this is a step that a lot of novice tuners do get worried about, thinking that they're going to damage the engine if they don't have the fuelling and the ignition absolutely perfect. |
| 00:14 | The reality is that nothing could be further from the truth and if we have the engine running massively too rich, our only real danger at this point is perhaps fouling the spark plugs and if it's too lean, chances are it's simply not going to start. |
| 00:27 | We'll also see during this step just how quickly we can make block changes and get our air/fuel ratio into the target and get our engine running happily. |
| 00:36 | And on that point, it is important to note here, we aren't aiming for perfection, all we're trying to do is get our air/fuel ratio approximately into the ballpark. |
| 00:47 | We also need to remember that we are starting from a cold engine, if we look at the moment we can see that our coolant temperature's sitting just below 10°C so we are going to be dealing with some warm up enrichment. |
| 00:57 | Our air/fuel ratio's likely to be moving around so perfection is not what we're aiming for within this particular step, we just want to make sure that the engine will run and make sure that we can get our air/fuel ratio approximately within the ballpark. |
| 01:10 | On that note, we probably want to at least refresh our memory on what we're aiming for in terms of air/fuel ratio so we can come across to our lambda target table and we can see below 1000 RPM, we've set our targets to 0.95 lambda so that's about what we're going to be looking for there. |
| 01:29 | Again not super critical at this point. |
| 01:32 | Another note here during our startup and this will also come into play when we are doing cold start, warm up enrichment testing and optimisation, is that we do want our lambda to come online straight away and you'll remember we've already discussed this but let's just go back and have a quick look at this. |
| 01:52 | If we come to our inputs here and we come down to our lambda sensor, we can see that we've got our sensor warm up set to ECU startup and generally what I would suggest is that you would start with this on engine startup, we already discussed this in a previous step. |
| 02:09 | That's how we want to leave the lambda control set because it will delay startup of the sensor and helps to extend sensor life by avoiding thermal shock but the problem with that is if we leave it on that setting here, we're going to have the engine running for perhaps 30 or 40 seconds before the lambda sensor actually comes online so during that time we're blind to what the actual air/fuel ratio is so we'll leave it to ECU startup at the moment and we can come back to our fuel table, we can also see that we've actually got our lambda already displaying here down in our bottom screen so we know what our lambda is, albeit at the moment the engine obviously isn't running. |
| 02:46 | Next let's have a look at what we're actually going to be doing in our fuel table and we'll start with how we can make some of these changes so we know what we're going to be doing so if we just click and select an individual cell here, there's a variety of ways we can make changes. |
| 03:00 | The simplest of course is using our plus key, that will add 1% to our volumetric efficiency every time we press it. |
| 03:07 | Likewise, pressing the minus key will of course take away 1%. |
| 03:11 | Obviously that's a reasonably fine adjustment and we're likely to find during our initial startup that we're going to need coarser adjustments. |
| 03:19 | So we can also use our shift and plus, that will add 5% per press and of course shift and minus will subtract 5%. |
| 03:28 | Just for the sake of completeness, and we'll see this as we go further through the worked example, we can also make finer changes by using the control and plus, that will add 0.1% and control and minus of course subtracts that and again for the sake of completeness we can use math functions as well. |
| 03:46 | Let's say for example we want to increase the current cell by 5%, well we can enter a value of 1.05 and then holding down the shift key and pressing the asterisk key, or multiplication symbol, we enter 1.05 multiply, when we press the enter key, we can see that that's the change that has been made there. |
| 04:05 | Another point that is worth keeping in mind, if you make an adjustment that you're not happy with, we can always use control Z and that will undo that change. |
| 04:12 | So that's the broad ways we're going to be making changes, you'll see some other techniques as we get into our steady state tuning but again for now, we're not aiming for perfection. |
| 04:21 | The other thing to consider here is the path that the ECU is going to actually map through this table. |
| 04:26 | We can see the little cross hairs showing that at the moment, obviously the engine's not running, we're at atmospheric pressure here so we're sitting at about 98 kPa and what we're going to end up doing is seeing this trace sort of do something probably a little bit like this as it starts up. |
| 04:42 | So that's where we're going to go through the map and in order to accommodate all of that, what I'm going to do is simply highlight all of the cells here out to 2000 RPM and we're going to adjust all of them together, again just making a point, we're not trying to individually tune each cell, that will come a little bit later. |
| 05:02 | We do need to consider here that at least during the cranking and initial startup, we will be affected by our cranking enrichment tables, as I mentioned we've also got warm up enrichment coming in here but for the time being, we can really overcome this just by increasing or decreasing the entire fuel table to get us up and running. |
| 05:20 | Last thing to mention before we actually crank the engine for the first time and try starting it, is that we do have no idle speed control on those engines so we will be needing to use some throttle input to keep the engine idling, particularly when it is completely cold like this. |
| 05:35 | So during this process we'll be able to see the throttle position here in the bottom right hand corner and it's likely that we may need somewhere in the region of maybe 2-3% to initially get the engine started but we'll be able to manipulate that with our foot once we get going. |
| 05:50 | Alright at this stage, let's try cranking our engine for the first time and see if we can get it to start. |
| 06:06 | Alright so straight away our engine actually started up actually relatively well. |
| 06:10 | Just using a little bit of throttle at the moment just to keep it idling and if we look at our lambda, we can see, 0.85, 0.86, 0.88, it's changing around a little bit. |
| 06:20 | We are obviously a little bit rich but we also are quite high in our revs so we'll bring that down just by closing our throttle and see where our lambda comes to. |
| 06:28 | At this stage, let's just use the minus key and we'll pull out a few percent fuel here. |
| 06:34 | I do want to just allow a little bit of time after I make an adjustment to let that change actually take place, so we can see we've got ourselves down to 0.90 at the moment, take another 2% out of there just using that minus key, we can see at this stage we're pretty close to our target, another couple of percent should get us to 0.95 which it has and we can see our throttle position there, still sitting at 2% so I am still using the throttle to keep us idling. |
| 06:59 | At this stage as well, also worth taking note that if this is an engine of unknown origins, we'd be wanting to watch at this stage for any obvious fluid leaks, listen out for any nasty mechanical noises and while we are running the engine here as well we can see we've got our three pressures over on the left hand side here. |
| 07:18 | The top of these, analog voltage three, this is our map sensor, the one in the middle there, analog sensor eight, that is our oil pressure, so we've got 4.5 bar of oil pressure, nice and healthy there, nothing to worry about and our final one is our fuel pressure. |
| 07:34 | Alright so let's have a look at what we've got now. |
| 07:36 | Still using a little bit of throttle, let's just see if we can let the throttle go and see if it will idle by itself. |
| 07:42 | I'd expect it will be quite low but we can see that it's holding an 800 RPM idle. |
| 07:47 | Down at this point here obviously we are a little bit richer so again we can use a little bit more of our minus key there just to get our fuelling into the ballpark. |
| 07:57 | At this stage I'm comfortable, we've got our engine started for the very first time, everything looks like it's OK, we're ready to move onto the next step of our process. |
