20v Tune problems: Microtech LT10s

[GOT-20V]

Hey,
I have a 20v in my corolla with a microtech lt10s, and i'm asking for help on the best way for it to be tuned? Currently tuned in Map but it gets 330kms to a tank of fuel and has a hesitation right on 2500rpm everytime. Would a tps tune be a better option? Can you tune it to have tps down low and map up top?

I know microtech is awful due to the quads on 20v but i have seen cars running fine with this ecu, car has exhaust and standard plenum.

Please help as my tuner is more an adaptronic man.

[Skylar]

Well, you aren't really helping diagnose the issue without fuel and spark maps. Tuning off hand controller or laptop? A 3D graph of RPM and load with AFR would really help to see if the car is tuned super rich or you have a fuel leak somewhere but you won't have this.

Flatspot at 2500rpm: Does it do it at any load/throttle? Is spark being pulled/advanced? Check AFR with a wideband? Where does the VVT switch(I have no idea if this is the cause)?

I would rather not do a TPS tune since you have a working MAP. Some ECUs allow two maps to be blended with different load inputs but I don't think micros do it; never looked into them too much.

Where are you? maybe someone could recommend a tuner who could re-tune it close to you specialising in microtechs.

[GOT-20V]

Tuner has been doing it with hand controller plugged in as well as his latop. unfortunately i don't have a 3D graph..

Flatspot does it no matter what, in the morning you take it for a drive and it takes 5 mins for it to kick in. Makes me think its some sensor that only comes in after it's heated up :/

I say tps tune because my mates 20v with haltech runs great in tps tune and gets 550km to a tank, i'm really itching to get economy from this car.

Here is my dyno graph when the conversion was first done, as you can see vvt kicks in hard, does anyone else have this with there microtech.

[Skylar]

Do you have the tune file that's on the ECU? Take snaps of fuel and spark maps see if the 2500rpm cells are really different to the other cell around it. Even injector opening times for a few cells will half tell you whether they're near what they're supposed to be(did that even make sense?).

Switching to TPS as main load source won't really help if the tuner can't tune an engine. Not saying he can't but the car seems to have problems. It even sounds like you map line isn't connected but the car would run like shit if it wasn't.

I would like to help but without fuel and spark maps or even a AFR line on that graph, there's not much I can do.

[GOT-20V]

Skylar: Unfortunately i don't have the tune file either.

Could you enlighten me more on what you mean when my map line isn't connected propely?

I was doing some research on how people convert there ST to map with the BT ecu and how they need to change around there vacuum lines etc, i placed a carby fuel filter inbetween my vacuum line to my microtech map sensor and rearranged my Fuel pressure regulator hosing and my 2500rpm hesitation wasn't as much of a jualt just a slight bump i could barely feel. This makes me think it's something to do with vacuum pulsation with the quads?

[Skylar]

Where is the MAP signal taken from? If you want to check for pulsations, you really need an O-scope. MAP line not connected properly=tube between plenum and ECU has come off at an end or has a tear in it increasing the load reading to ECU and making ECU fuel for higher load.

Been a while since I played with a hand controller but wasn't there a screen that should you sorta which cell you were operating in and how much the injector opening time is? Really would like to watch what the MAP reading shows up as on the ECU at the 2500rpm stutter.

[GOT-20V]

Okay, now tuned in tps and i find it running alot better. Seems to run a little rich still as it isn't all that economical.

My problem is the bump at 2500rpm thats circled, what the hell is it? could it be to do with an air valve not opening properly,a wiring issue perhaps? has anyone else had this happen to them.

[meadan]

my 20v has a similar flat spot around there according to the dyno graph.

I havent had it it tuned personally, but the previous owner got it done. Mine has a microtech LT-8 by the way.

I get about 400km to a tank.

[Jonny Rochester]

Look at both your fuel and ignition maps and correction maps and see if anything erratic is happening at 2500rpm.

Is the fuel map in "all maps the same" or "matrix" mode? Once you have your 2D fuel graph/map roughly sorted, you should switch to 3D "matrix" mode. Then once in 3D mode, you will need some extra fuel around 1000 - 2500rpm at thottle openings less than 50%. This is because lots of air is let in by the quads once they are cracked open. You will also need extra fuel around full throttle and 7000rpm, and less fuel at full throttle and 2000rpm. (Also less fuel at 0% and 6000rpm than at 0% and 3000rpm, but not so important).

Once the mixtures are ok at most throttle openings, at steady speed, you may then find you have a dead spot on acceleration. Find your "accelerator pump" settings and give it heaps. The quads will love it.

The circle in your graph is only at 14 afr, which is not too lean. But is a little lean if the throttles are open. You want more like 12.5 afr when the throttles are open, which the later part of your graph is.

Look at the ignition map. When you were on the dyno, I expect the throttles were at 100% the whole time, so you only need to look at the 100% parts of the the fuel and ignition maps to find a problem.

At 100% throttle, ignition should go from about 10 degrees up to maybe 36 degrees through the rev range.