Emerald ECU advice

[simonjrwinter]

Ok, cobra replica, jaguar 42.supercharged V8
Emerald ECU was mapped by Dave Walker on rolling road when owned by PO
As the car was hot when setup the cold start was not addressed
It starts pretty much instantly when cold but dies instantly unless the throttle is pumped to keep the revs up
I've got the software from emerald but despite a cold start crib sheet sent by emerald, I've had no luck in getting it starting cleanly. Any advice?
Simon

[SuperchargedVR6]

Sounds like it hasn't got an idle valve, or if it has, it needs further tuning work to get more air and fuel in.

Edited by SuperchargedVR6 on Monday 7th March 14:10

[DVandrews]

It needs more air, I would crack the throttle open a little on the adjuster and see how it fares, also make sure idle control is turned on and the idle throttle position is within its remit, allow a generous adjustment of say 20 degrees and set the update rate to 10. If you find the hot idle too fast then drop back the idle advance until it is where you want it.

Dave

[Steve H]

If the OP is describing accurately when he say the throttle needs to be "pumped" then I'd suggest the car is short of fuel when cold, not air.

[DVandrews]

Not necessarily, pumping the accelerator also introduces a lot of air. I have seen the same situation 50 or so times with Emeralds having installed over 200. Sometimes it is a combination of low fuelling (cranking fuelling soon Decays) and air, sometimes just air. In my experience it is far easier to adjust the throttle idle position than it is to recalibrate the injection corrections. If the extra air doesn't hit the spot, then some adjustment to the cold start injection corrections might be in order, it is a tricky thing to adjust as the engine quickly warms up and moves on to another entry in the table.

If the OP would care to post here the cranking fuelling adjustments and the injection corrections for coolant temperature I can probably comment more succinctly.

The ignition timing value at 500RPM has a role to play in preventing idle drop back too.

Dave

[simonjrwinter]

How's that?
Simon

[reggid]

http://www.emeraldm3d.com/media/software-manuals/E...

[simonjrwinter]

Already downloaded that..........can't get my head around it........I'm from the carburettor generation!

[DVandrews]

The initial prime and cranking enrichment look low, but most importantly the coolant correction for temp is low, try these figures..

-30->-10. 55
0. 50
10. 40
20. 28

Then leave the higher temperatures alone.

I'll have a look at the cranking and initial prime later and post up.

Dave

[spitfire4v8]

Spending 150 pounds on a basic wideband lambda would tell you most of what you need to know (with a display .. one update I'd like ememrald to do is have the afr displayed on the injection corrections page, I'll suggest it to karl) .
But also you must have the engine set up correctly in terms of base idle airflow, ignition timing etc. The start up and warm up strategy is the bit you do last when you are absolutely sure youve got the basic running right otherwise anything you do on the main map will affect the warm up phase.

[DVandrews]

The wideband won't help with the startup, it's great when the engine and sensor are up to temperature. Once the basic map is good, the injection correctIons can be applied, the ones I have posted will help and then some judicious adjustment should perfect the cold start.

The Emerald has self learning so you can set a target AFR and then use the engine normally, the ECU will then suggest fuelling adjustments at the various speed/load sites which you can choose to apply.

Dave

[Pumaracing]

Baseline cold start values for Emerald systems are here.

http://www.emeraldm3d.com/media/software-manuals/E...

[simonjrwinter]

Pumaracing said:

Baseline cold start values for Emerald systems are here.

http://www.emeraldm3d.com/media/software-manuals/E...

Thanks, but see first post.

[Pumaracing]

So you already have this Emerald document but have taken absolutely no notice of the information in it? You post a photo of your map with completely different cold start values in it but still say you don't what what the problem is. Are you really that stupid or just too lazy to change the values in your map?

[simonjrwinter]

Thanks for the insulting words, if you had bothered to read the post you would see these are the figures I am STARTING with.

[DVandrews]

How DARE you post again .

Dave

[reggid]

here's an out there idea, if you know nothing about ECU's and dont want to learn. then drive back to shop that tuned it and leave it over night and get them to sort cold start in the morning(s)....

[Pumaracing]

reggid said:

http://www.emeraldm3d.com/media/software-manuals/E...

Oops, sorry I didn't spot you'd already posted the same document as me. Seems we were both wasting our time anyway, lol.

[simonjrwinter]

Seems like I came to the wrong place for help and advice (with one notable exception, thanks dvandrews)
So glad you other guys know it all, please accept my apologies for wanting to learn.
I won't make the mistake of asking here again for assistance.

[stevieturbo]

simonjrwinter said:

Seems like I came to the wrong place for help and advice (with one notable exception, thanks dvandrews)
So glad you other guys know it all, please accept my apologies for wanting to learn.
I won't make the mistake of asking here again for assistance.

There's a difference between wanting to learn, and heeding what you're being told.

Whilst it is very very basic indeed....may as wells tart here, given it's from Dave/Mr Emerald himself.


http://www.amazon.co.uk/Engine-Management-Optimisi...

And as others have said....you're making the assumption the problem is with ecu settings. The problem could equally be with the mechanical install, namely the amount of air you're providing the engine via the throttle, as you havent yet confirmed whether there is an idle air valve in use ?

So it could be as simple as just needing more air. With the lack of an idle valve, this air will need to come via the throttle blade.

But really...get a good hot start, good hot idle then you almost need to work back from there.

Starting with no cold enrichment etc and adding some fuel etc until it starts easily when cold.

Starting rich from the outset, starting with too little air, can just mess things up making starting hard whether things end up right or wrong.