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[coopertrooper2001]

Anyone with experience of the Emerald ECU and cold start issues?

I am running a Supercharged MPI and for the first minute or so the engine sounds rough, it kinda chugs, like there is insufficient choke. It also take a lot of cranking before it catches.

I have been looking at the cranking enrichment settings on the injection corrections tab. This has been modified by my tuner which improved things slightly but its still not right. I have attached a copy of my map to this post.

Any suggestions folks? I am guessing increase the enrichment in the 30-50/60 degrees C range...

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[Sprocket]

Not ever having seen the Emerald software, im using an educated guess.

You have to understand what is happening when you turn the key fisrt to work out which bit to tune.

Cranking enrichments is the first, this builds up the fuel film on the manifold and port walls, this is added to the warm up enrichment pulse width which is added to the VE (injection) map pulse width. Once the engine has cranked and cought the crank PW drops out and the afterstart PW jumps in, this is again is added to the warm up and VE pulse width. after a short period of time, the afterstart PW is reduced so that all you have is the warm up and VE PW. as the engine warms up the warm up PW is reduced untill the engine is up to temperature and purely running on the VE PW

If you have issues cranking and getting it to catch, adjust the crank PW, if it catches but then stalls almost imediately, adjust the after start PW, if it starts and runs for a short period but then faulters or stalls, adjust the warm up PW. This is assuming you have a well tuned injection map.

I Assume the 'Initial inj Prime' is the crank pulse width this is the bit that will start the engine when its cranked. The warm crank pulse widths are rougly around 50% of the warm idle PW, that will be around the 80c area, and the cold crank PW is a rule of thumb 3 times the warm crank PW, at around -40c.

The next bit is a little confusing with the terminology used i'll assume this is the afterstart enrichments. I assume that 'Engine Turns' is reffereing to engine cycle. One engine cycle is is 2 revolutions and 100 cycles is 200 revolutions. at an idle speed of 1000rpm ( for ease of explaining) thats 1000rpm divided by 200 equals 5, 60 seconds divided by 5 is 12seconds, so the after start lasts 12 seconds and during that time the % of the Initial inj Prime PW is reduced.

I dont know if thats right, but looking at the map there are big holes in it and some large steps.

Thats the crank and afterstart out the way

The warm up enrichments also look a little bare as you start to get warmer. The coolant temp enrichment around 30 degrees is almost non existant. As for the air temp enrichment, i dont understand that one, lol though it is probibly self explanatory.

Like I say, I dont know much about the Emerald set up, but most programamble ECUs work the fueling enrichments in a similar manner, its just the software that differs and the ease of its use

Do you not have a manual for Emerald MD3?


If this is a Vmax Scart kit, do you not have a back up file you can use, may be worth giving Stu at Vmax a phone, im sure he wouldnt have let it out the work shop if it was that bad.