Initial Ignition Table

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jammy86
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Initial Ignition Table

Post by jammy86 »

Hello,

I have a 1600 Ford CVH Turbo which fires up and idles no problem on my MS2v3. I have not yet moved the car more than a few meters but it's not too far off! For the initial spark map the imported base map didnt go above 100kPa and so with a bit of googling about I've created this as a base spark map to use to get me going. Does it seem an OK starting point? I know this is an "every engine is different" topic, but there is a wealth of experience on here and if anyone spots a rookie error then this post will have been worthwhile.

Picture and msq attached.

Thanks,
James.
Red_bull
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Re: Initial Ignition Table

Post by Red_bull »

I am running the same engine. However i'm deff not final on mapping and haven't looked into if for a while. Can you post you AFR as well. I will have a look for you. Mine runs pretty wel
jammy86
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Re: Initial Ignition Table

Post by jammy86 »

Hello,

I've not altered the AFR table yet from what the AFR generator makes. I fired up yesterday and found it difficult to get the engine speed down to a reasonable idle. I have a Piper 285t2 camshaft and I think there may be too much air at idle. I've wound in the idle screw and the idle speed valve loses reliability below 25% duty. With duty at 0 and the idle screw wound all the way out it still wasn't quite happy enough. I did this work previously on my MS1 and only upgraded to MS2 over the past few weeks. I'd like it to idle at ~900. My plan is to put a restrictor in the feed to the ISCV to try and reduce idle speed with the ISCV at 25 minimum duty.

I found 18deg of ignition is where it was happiest at about 1000-1100 RPM idle speed, but I had the AFR quite low at 13. I was reading up some stuff on the FRST engine last night and standard AFR at idle is 13.9. I'm going to try and sort the air issue before going much further.

Attached are msq and log of yesterdays running.
grom_e30
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Re: Initial Ignition Table

Post by grom_e30 »

have you tried less timing at idle,usually having more air and less timing at idle can be more stable. is this a erst? if so series 1 or 2?
1990 bmw 320i daily driver with m20b25 ms3 sequential fuel, 380cc injectors, d585 coil near plug, home made cam sync, launch control, fan control, vss, homebrew egt logging what's next????
jammy86
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Re: Initial Ignition Table

Post by jammy86 »

Fiesta RST engine in a Ka. Less timing seems less happy (subjective), but then I've not done the full sweep of timing and fuel yet. I'll probably have another run through it today. I've set the AFR table up with 13.9 in the idle region so I'll have a play with that. I'll also confirm fuel pressure soon.
grom_e30
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Re: Initial Ignition Table

Post by grom_e30 »

you have a kaT :D

the stock timing for a erst is some where about 12btdc at idle if thats any help.
1990 bmw 320i daily driver with m20b25 ms3 sequential fuel, 380cc injectors, d585 coil near plug, home made cam sync, launch control, fan control, vss, homebrew egt logging what's next????
jammy86
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Re: Initial Ignition Table

Post by jammy86 »

grom_e30 wrote:you have a kaT :D
Yes, had it for many years and it's been off the road for...oh... 6 or 7 now being restored. I bought an MS1 back in 2008 and never got it going properly, finally got it up and running within the past few months and changed the cpu for the MS2. Slight financial issue which means it wont be on the road before winter now I don't think but maybe....

Anyway... Yesterday I played with it a little more. I added a restriction to the ISCV and this helped to pull the revs down a little. I'm surprised how little a difference this made, I probably reduced the diameter of the pipe to 1/3 or 1/4 of the original diameter and this only made about 200RPM difference. This lead me to think there may be an air leak, but if I unplug the ISCV then the engine pretty much dies so I'm going away from this theory.

Back to the original questions about ignition... Once up to temperature I tried to set the AFR to 13.5-13.9. I was constantly chasing my tail as I appear to suffer from significant MAT soak. The car is in the garage right now with no airflow and the pipework to make the engine fit the Ka is long and heats up pretty badly. The air temp sensor is not an open/exposed element type, it is the standard sensor however, so my MAT is getting up to 50degC just sitting in the garage. I can rig up a small fan to pass some air over the intercooler but it's not going to be much.... It's not helped by the air filter living behind the radiator either.... (to be addressed in the future). When its all up to temp I can make it idle about where I want it to (~900rpm) at an AFR in the mid to high 13's. I can swing the ignition massively and it has a significant effect on both engine speed, AFR and vacuum. I have checked the running base timing with the strobe and believe it to be good. I may be 1-2deg out as access to the timing marks is very difficult and so I need to lie under the car looking up at the timing marks, it's as good as I can get it anyway. The engine will idle at 12deg BTDC but sounds a little rough. At 16deg, my previously favoured value it all sounds a little better. However if I go as far as 26deg BTDC then I get an increase in engine speed, an increase in vacuum (a smaller number, from ~50 to ~43kPA) and it all sounds much happier but getting the engine speed down below 1000RPM is difficult...

I do know that the stock vacuum is 50kPa (absolute) on this engine. I have checked fuel pressure and it's 3barG.

I think I may be worrying about nothing here... it's idle... it works... the cam is probably throwing it all and it's not exactly an engine known for good idle. I should probably just start driving the car and worrying about the loaded conditions instead of idle...

Anyone have any further thoughts about the ignition map shown previously? I need to tidy it all up as I've been modifying it with the shotgun approach when playing with idle.

I captured some of the warm up on a log, but it stopped when I started playing with the tables and I didn't notice. I'll try to grab a few examples later and post them up. How should I approach the MAT soak issue? Just get it all up to temp and stable then start the tuning? Disable the air density correction? I may change the sensor to an open element type, this should fit: http://www.ebay.co.uk/itm/361410827046? ... EBIDX%3AIT
jammy86
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Re: Initial Ignition Table

Post by jammy86 »

Brief log of idle and ignition swing...
jammy86
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Re: Initial Ignition Table

Post by jammy86 »

Reading a book earlier it suggest you keep the ignition well retarded when using a high duration cam to keep the idle speed down. I guess that's the route I should go down...
Yves
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Re: Initial Ignition Table

Post by Yves »

That's plain wrong.
jammy86
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Re: Initial Ignition Table

Post by jammy86 »

Really? It does seem counter intuitive. I'll admit that the engine does sound its happiest at 26deg advance.

Today I did a few things. I checked the injector dead time and found that although the base value was about correct at 1ms, the slope was actually about 100us/volt. While doing this I also realised that the fuel pressure was 0.5bar too high. It was 3 barG when engine running, but with a manifold pressure of 0.5barA (-0.5barG) this makes the actual fuel pressure at the injector 3.5barG. I tweaked this and re made the fuel table using the VE generator. Overall result pretty similar, just larger VE numbers as you'd expect. It does seem to handle the increase of electrical load a little better and the fuel pump sounds a little happier :) Auto tune for idle was able to hit 13.9AFR which it had struggled to do previously.
Yves
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Re: Initial Ignition Table

Post by Yves »

a high duration cam will cause additional overlap at TDC. This will cause a less than perfect mixture that will burn slower, thus requiring more initial timing.
jammy86
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Re: Initial Ignition Table

Post by jammy86 »

Thanks for the feedback. How should I transition from idle advance to running? Here is my latest ignition table after a little more reading about from people with similar engines.
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