Tunning Problems

insane_clown · Post by **insane_clown** » Wed Jun 28, 2006 10:13 am

This is it, I have just about given up on the injector timing and take it to a dyno.
The hassle is when the car idle it will idle smooth when I have the A\F @ 11.5-12.0. Any leaner the car will start to cough and splutter. When I get it down to 14 the car will just stall.

Under load everything is going pretty good. I have the A\F @~10 -11 at pressure and 12 @ crusie.

I'm going to take the car for a bit of a drive this morning and see if i can figure it out but any advice would be appricated.

Microtech mtx-8
4g63 turbo
450cc injectors
standard fuel pump and turbo
Brand new spark plugs and 4 wire O2 sensor

crshbndct · Post by **crshbndct** » Wed Jun 28, 2006 10:17 am

wouldn 12 at cruise be better and 14 at load?

insane_clown · Post by **insane_clown** » Wed Jun 28, 2006 10:43 am

It's just the idle which I'm trying to work out. Is 14 to lean, should it be around the 12.0.
The rest i'm slowing getting, they are better than what they were.

jakobsladderz · Post by **jakobsladderz** » Wed Jun 28, 2006 11:20 am

Idle ignition timing might be the issue.. I couldn't get my engine to idle leaner that about 13:1 when I was running 20+°BTDC at idle. Dropped the timing down to about 10°BTDC and it happily idles at 15-15.5:1. I had the same thing happen with the G54 engine in my old turbo magna too.
A mate of mine has a microtech in his Gemini and he also had trouble getting the engine to idle stoich. Part of the trouble with the Microtech ECU's is that the injector dwell resolution is ~0.1-0.2ms which is way too coarse when trying to tune idle with bigger injectors. 0.1ms one way is lean, 0.1ms the other way is rich.. Also, there's no opening time compensation to handle battery voltage changes(electrical loads cause significant mixture changes due to opening time changes in the injectors).
14.7:1 (stoichiometric = good for economy + emmisions) or leaner is the target for less that 1/2 atmosphere (say 7psi of vacuum, whatever that is in "Hg)
smoothly progress to 13.5:1 (max power mixture level) or so at atmospheric pressure.
heading towards 11:1 (safe for pinging/cooler valves etc) at 7PSI or more.

If you don't have a Wideband set up permanently on the car (and keep an eye on it) you'll definately want some margin on these values to guarantee that the mixtures dont lean out at any stage..

insane_clown · Post by **insane_clown** » Wed Jun 28, 2006 12:45 pm

Thanks jakobsladderz, I was thinking that but I thought I would post the question to see what other people say.
I also had a problem with the TPS. I would touch the peddle and the TPS screen would show the throttle opening, it would go upto 10% then go back down to 00% and start all over again. So i moved the sensor to bypass the first bit.
Now it goes from 00%-99% nice and smooth.
Took the car for a run and it went shit hot, still running a bit rich but a hell of a lot better than what it was.

I put a wideband in the car last weekend (thats another story in its self) and it had helped me out a lot.
Once I get this idle timing done I'll be happy

:beer

jakobsladderz · Post by **jakobsladderz** » Wed Jun 28, 2006 1:30 pm

looking on the net just before and have found some more info about fuel mixtures. Apparently 13.2:1 is the lean end of max power mixture and 12.5:1 is the rich end. Over this range of mixture settings the power is within 1% of maximum (other effects aside). So I was out by about 0.3 AFR. For water cooled lower compression motors like ours, running 13.2:1 will be fine for atmospheric manifold pressure. VW people with aircooled engines run 12.5:1 or richer at atmospheric in order to keep the head temp down..

insane_clown · Post by **insane_clown** » Wed Jun 28, 2006 3:24 pm

I have just been playing with the setting and I have another question.
With the injector setting :sequental or multi.

I know it was set to sequential when I had the ECI but now since I have the L300 setup should I change it to Multi. When I tried it, it seemed to run better and I had better control of the fuel values and A\F ratio.

I asked this question a year ago on a forum (can't remeber where) and was told to leave sequential but now I'm wondering ?

:beer

jakobsladderz · Post by **jakobsladderz** » Wed Jun 28, 2006 3:52 pm

I Remember playing with this setting a while back and neither setting was true sequential. one setting fired all injectors at once, the other fired them at 180°crank from each other.

I'd say use whatever works best in your application though. There is minimal difference in power or economy between any injection regime unless you have the ability to trim individual injectors, which the MT-8's can't anyway.

The setting you have chosen may make one injection per cam rev instead of two, making the opening time twice as long and subsequently half as sensitive to opening time/ dwell resolution errors.. I don't know for sure..

insane_clown · Post by **insane_clown** » Thu Jun 29, 2006 7:25 pm

And it continues.......

I finaly got the Idle at 14.0:1. But now a new problem has come about.
When my thermo fans kick in the engine stalls under the load. Is there a way to adjust the load for when they kick in or do I have to look at another option.

Thanks for all your help sofar guys.

:beer

Post by **TOMSUN** » Thu Jun 29, 2006 8:42 pm

what wideband you using???

Starion VR4 · Post by **Starion VR4** » Thu Jun 29, 2006 8:55 pm

Ok, have a look at yr ignition timming at idle say 800RPM, the next RPM point lower EG 700RPM increase yr ignition timming by 5Deg, then at 600RPM another 5 Deg, also up the fuel below std idle fuel point, as the engine need more fuel as it slows. Now as for Sequential, if U have it setup correctly EG it fires the injectors in firing order 1-3-4-2 & u can control the injection firing point then yes it will be better throttle responce & fuel economy. But yr injector has also got 2 be big eough to inject all the fuel in >2m/s. Now as yr engine speeds up the injection window gets shorter due to the Speed of yr engine, at 4000RPM u have >.5m/s to get all fuel in! Honda & nissan both do sequential injection up to 4000-5000RPM, then they both change to Grouped Injection. My advise.... run grouped injection, the difference between the 2 is not enough. My Staz when i changed from Seq to Grouped injection, I had to take .7M/S of fuel out to keep the same idle O2 setting. :beer

insane_clown · Post by **insane_clown** » Thu Jun 29, 2006 10:50 pm

Okay, Tomsun I have just installed a 4 wire NTK Lambda sensor, hooked up to my ECU and getting the readings from the hand controller.

Starion VR4, I will have a look at all those settings tomorrow.
:beer

insane_clown · Post by **insane_clown** » Fri Jun 30, 2006 4:20 pm

Okay here i go again :)
I got the the main problem solved
I have got the main things done but I'm not happy with it.
With the fuel ratio @ 14.7 idle @ 20hg" 850 RPM with the injectors @ 1.06 ms. The car does not seem to like it, it always seems like it is on the edge of stalling.If i increase any settings to do with the fuel mixture the A/F will jump to 11.0.
When I advance the timing the revs sightly increase and the A/F goes down to 11.3 and no matter what I do there is no inbetween. When i try and lean the mixture it goes to 14.7 and stalls... No fuel.
I have advanced the timing all I possible can using the ECU.
The question I have ( I would try it but I don't have enough time tonight)
I'f I back off the crank sensor say from 10 BTDC to 6 or 5 BTDC would that help with the timing adjustment.

The workshop that installed this ECU did a half assed job (26 weeks to do the job) and I ended up running around getting the bits they needed and it wasn't Maztech

The people who did the crank sensor did it for a Rotory if i remeber corectly and I know that the rotory's have to be set to 6 degrees BTDC.

Just bouncing an idea around
:beer

jakobsladderz · Post by **jakobsladderz** » Fri Jun 30, 2006 4:34 pm

sounds like its stepping between to fuel time steps (like 1.2 then 1.4ms) and that this is 14.3 then 11:1. check what the fuel step is like on the hand controller. If this is the case you may not be able to do too much about it with that ECU..

Duncan

insane_clown · Post by **insane_clown** » Fri Jun 30, 2006 4:48 pm

Thats what I was thinking. What I was saying about the crank sensor is just me grabing at straws. I still might give it a shot when I get a chance and see what happens.
I know Microtechs run rich , but i didn't realise that bloody rich. (might explain why I was getting 200 kms at tank with the standard ECI)
If I can't get the A/F right after playing with the crank sensor I will start saving py pennies and by another EMS.

I will give anything a shot guys, throw some ideas at me.
Nothing that includes petrol,naked flame, brake fluid and chlorine

:beer

Austarion

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