Random URGENT QUESTION!!!

4GTuner

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D3bb4

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Jan 22, 2008
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Hey guys,

anybody on here messed about with tuning???

I've built an engine testing rig for my capstone project/thesis at uni (Mech Eng Degree), and been given a base map to run it the engine I've attached to it (also wired up MoTeC M800 to it)

No errors, nothing... cept I'm having to pre-load the motor with a crapload of fuel to get it to fire up, upon doing so it dies almost instantly...

Considering the lack of backfires, I'm pretty sure the CRIP and timing is alright, so am thinking it might just need more fuel in the map...

Any suggestions about this? Just want to get this thing idling, nothing more for the time being... been told to mess with an 'overall fuel trim' to get it to work? So I'm assuming this might bump up fueling across the board?

Feedback appreciated asap, thesis is due friday! Considering just messing with it tomorrow... Won't blow it up dumping fuel in it :D
 
The overall fuel trim simply adds or subtracts a specific amount of fuel across the entire map.

I would firstly look at your injector settings, trig/ref settings and ensure they are spot on.
Use a timing light and ensure you're light is showing what your Motec is indicating when cranking.


Are you using a base map of some sort? If not, call Motec for one.

I use an m4 but the concepts on the Motec are pretty much the same.

You should be playing with your cold start settings.

Injector timing is also something you needed to consider.

Check it the Motec website/forum. Very helpful. Calk the tech support guys also, they'll take type map and look over it for you via email.
 
Pretty sure it's an open loop setup. Might try looking over the readings though.

Using a base map supplied by motec. Tech support basically told me that I'm now up to tuning... play with the fuel.

Tech support has already told me that the timing should be right (in that a 2GR-FE has a CRIP of 516 deg, maybe plus minus 5 deg) - so the trig/ref settings should be spot on, otherwise it wouldn't fire in the first place. If the sync/ref don't line up, or it chucks a sync/ref sync error, don't get spark.

Wish I had another week to mess about with the map!!! Think I'll mess with the overall fuel trim then, just dump fuel in it. Just needs to run, not necessarily very well. :)

Thanks guys :)
 
So you have checked your actual engine timing with a timing light to ensure that your ECU and actual is matching?
There are 2 ways of doing this.
1. set your entire ign map to a value (probably 10 deg btdc), crank your engine and confirm that the light sees the same value.
2. there is a setting somewhere in the software for setting static ign timing. set to value and test to light. If not matching, adjust your CRIP until they match.

Also you can run tests with the MOTEC ECU.

Go to:
ECU Manager: Ignition test / Injector test found in the utilities menu. Just make sure your fuel pump is off. You should hear the injector pulsing when selecting.

Have you wired the injectors based on firing order or by cylinder order?

Keep in mind that by default, injectors are wired in by firing order. If you have done cylinder order, you will need to change your injection / ignition sequencing in the software. Or change the pins on the ECU loom. Easier in firing order in my opinion.

With the fuel:

MOTEC is open loop until certain conditions are met before it goes into closed loop.

Play with these settings:

* IJPU (this determines the type of injector used) - F1 for more info in the s/w - you can use this value instead of trim. I believe from memory, the bigger the number, the more fuel that is injected.

* Fuel - Cold Start (start with typical values) - use F1 for help

* Other compensation tables (keep in mind, when cold, you will have all types of other trims happening - cold start / eng temp comp / etc)

* Fuel - injection timing for a cold start or first start, best to inject before the valves are open. Depending on your cams being used, this will determine the value. There are calculators online. Or find out with motec for your cam specs. To fine tune this area (after you get it running), allow the engine to run (full temp), and monitor the a/f ratio while you adjust the related cell. Adjust and obtain the value with a richer value. This is more critical for start up and low load as up top, the injectors are pretty much open most of the time anyway.

Hope it helps.
My Motec M4 fired up first time on the AMG. But I tweak it every day!
 
I'll have a go of it, thanks.

I tested all the components ages ago. It's wired up 100% (firing order, sensor readings, etc.)

Think it's just the software side of things that needs doing now, so I'll play with the settings you've recommended :)

haven't configured the cooling system yet, so won't be getting it up to temp until after then ;) was just a test to see if it'd run.
 
hahahahahahahaaha.............. IT RUNS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Over_the_freaking_moon...

Suspected the injectors werent firing when we were cranking, so hooked up an oscilloscope to test the signal output from the motec. First to the test output function to get tune the reading, and then tested signal when press accelerator. Both times showed signal.

Tested ignition signal as well to be sure. First test output again, then decided to dump fuel and see if they're firing when it runs (on 5 of 6 cylinders). No worries, it gets signal...

Next test dumping fuel and cranking, testing for injector signal... NO SIGNAL...

Called motec tech support, told to look for a few things... eventually saw that when stopped, the fuel compensation was -100%... we have a winner...

went into fuel settings, leveled the compensation map to 0 across the board... STARTED FIRST GO!!!!!!!!!!!!!!!!!!!! (dumping fuel because of previous attempts to fuk with the map. hahaha)

It wants to idle at 6k rpm, so killed the ignition... let the tuning begin!!!!!!!!!!
 
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