ninja180

I know these ecu arent use a lot on mx5's but I thought I just try here for some help anyway. I hope someone has good general Tuning knowledge.


I have had some starting problems with my miata 1999 1.8 turbo.
When I turn the key on a cold start it takes 10secs then stalls;
second time it takes 5 secs then stalls.
eventually it takes 4 secs then starts.


My 0-500 ignition maps are minus 1.92 degrees
500-1000 ignition maps are 13.92 degrees
1000-1500 ignition maps are 14.43 degrees

When I look at the the adaptronic and megasquirt ignition maps in those ranges they are between 10-15 degrees.

If I alter my igniton map to 15 would I run the risk of knocking in those RPM?

Thanks in advance

OZMX-5

Just you answer your question quickly, it would be pretty safe if you were to run up to 20degBTDC timing at idle, depending if your AFR is at least stoich, and preferably a bit on the rich-side (say, 14.2:1). Anywhere between 16-19degBTDC is generally the acceptable range.

Have you not tried the manufacturers in South Africa for help?
No forum for these over there?

Ignition timing is probably the least of your concern when trying to get a good idle, there are things like amount of fuel, pulse width, TPS vs MAP, warm-up enrichments, Idle air control valve, etc. that would have a more significant impact on idling.

If you have a manual, I would regress everything and start from scratch and follow the instructions to the letter.

Also, check that everything mechanical is working fine, ie. Injectors, coil, spark plugs and leads.

If all else fails, you can cheat a bit and turn the throttle butterfly stopper bolt so that the butterfly remains ever so slightly more open at closed throttle, hence you increase your idle that way.

ninja180

Thanks for your reply.

I have gone through the manual and checked every mechanical mechanism. battery wires etc.

Adjusting the timing has helped tremendously. Cold starts takes one go but it still takes sometimes 5-10 seconds to catch on. I have noticed that the Cranking rpm speed is 200 rpm. Should it be higher? I am wondering if the starter motor is at fault?

OZMX-5

my cranking RPM is approx 250RPM. My starter and battery is strong.
Does your starter turn over quickly? In other words, does it crank as per usual before installing GoTech? If not then maaaaybe it's that.

One thing that I did with my MegaSquirt to help it fire-up easier, and I am a bit baffled as to why this fixes it, but is to change the "Required Fuel" value.

"Required fuel" tells the injectors how quickly and/or how long to open according to what AFR you are trying to achieve.

Try finding whatever you have as an equivalent in GoTech to change the Required Fuel value and increase it, ie. tell the injectors to open quicker.

Does GoTech have a "Flood Clear" option? this is where the engine will crank and provide spark, but does not open the injectors in order to clear the cylinders of any unburnt air-fuel mix.
Maybe it's on when you don't want it to?

ninja180

The flood clear option is interesting on the megasquirt but I dont think I have that on the GOTECH.

My car has low miliage of 25k and started fine before the tune.
The garage to tune my car also set my engine bay on fire. He had explained that some petrol spilt on the shop floor and my car was there.

I am concern that that might be a factor.

The reading on my ecu for idle is 900rpm and on the rev counter its 1000rpm.

So if my reading is 200rpm on the ecu it should be a little more.

What year is your car?

Other people are saying that the normal cranking speed should be 350 rpm.


I have just replaced the battery as it was easy but I'm not keen to replace the starter as it is quite awkward to reach.