Enrichment during warm-up

[oldeskewltoy]

Above is my current warm up enrichment table........ It isn't much to be desired.... I KNOW that....

My little 4AGE refuses to even get near a non-stalling idle, until 136 degrees, and even then I have to monitor it.... untill fully warm(160).


Any helpful assistance here???? I doubt things could be worse then they are.......

[JP]

What idle AFR does it run at each temp with those enrichments?

How are you controlling your idle-up?

[abently]

My little 4AGE refuses to even get near a non-stalling idle, until 136 degrees, and even then I have to monitor it.... untill fully warm(160).

This surely can not be a standard 4AGE ?

I have to agree on the AFR question, running it too rich is just as bad as running it too lean in terms of idling.

What CR, cams, pistons & piston wall clearance?

[oldeskewltoy]

This surely can not be a standard 4AGE ?

What CR, cams, pistons & piston wall clearance?

smallport 4AGE(.5mm overbore = 1606cc), CR 10.75 to 1, measured down to the first compression ring, cams are 226 @.050" 8.38mm lift

initial tune has 145hp and 112#/ft @ the wheels - dyno - http://i79.photobucket.com/albums/j1...eptitious3.jpg

It also is emissions compliant (once warmed up) - http://i79.photobucket.com/albums/j1...sionscert2.jpg

More details -
http://www.toymods.org.au/forums/sho...&postcount=294
http://www.toymods.org.au/forums/sho...0&postcount=24
http://www.toymods.org.au/forums/showthread.php?t=35553

What idle AFR does it run at each temp with those enrichments?

How are you controlling your idle-up?

There is no idling it during warm up... , it just stalls

Idle up is not yet in the system, my plan is for a simple single stage unit, similar to an AE86 idle up for load. I was trying to get the upper temp range (where the extra air isn't needed) percentages set, and then go back and add the idle up and the idle up enrichment

[abently]

How is spark holding up at those enrichment levels? 30% enrichment is potentially 8-9 AFR...

Factory piston-wall clearance?

Sounds like there is not much you will be able to do... if you want to keep those cams set the way they are.

[JP]

Do you have any ignition correction in place for cold idle seeing how there's no valve?

[jondee86]

Are you still using the OEM thermostatic idle-up valve on the throttle body ? If you don't have
the valve, you will probably have to crack the throttle open some to get enough air for cold idle.

Cheers... jondee86

[allencr]

I think it's more of an atomization problem then the engine needing to be drowned in fuel when cold.
A DCOE carb can start & idle smooth in just seconds without touching its enrichment device at all, temp around 40F/5C.

[oldeskewltoy]

the engine needing to be drowned in fuel when cold.

Let me rephrase....... the above enrichment levels are INCORRECT...... I'm looking to get some suggestions as to how much the enrichment should be.

I do fully realize that when temps get cold enough, she will need additional air, BUT from about 70 degrees or so, and warmer, she should NOT need more air during warm-up, just the CORRECT amount of fuel.......

I'm asking for some suggestions to input new percentages........

[JP]

when I setup my cold enrichment tables, I get the engine started and then tweak them while monitoring the wideband as the engine warms up.

[abently]

I'm asking for some suggestions to input new percentages........

Reduce it by 20% across the board and continue doing so, till you notice it gets harder to start/idle? Will mean having to do this once a day for the next week or two....

What rpm are you holding the throttle at, whilst this warms up?

You can get injectors which atomize the fuel better, may be worth looking into.

[oldcorollas]

for 4K on MS i have.

16C +35%
27C +26%
38C +15%
54C +5%
71C and above 0%

needs air bleed to idle for first minute or so.


to tune, basically....
crack throttle enough when cold to get it to idle, or have a bleed valve to help.
tune fuel and time as quick as possible to get smooth running at idle speed at a given temp, as it warms up.
repeat next day

you could, at a stretch, do something like remove thermostat while doing your cold start tune, as that gives you more time, since it will warm up slower.
it may not be perfect in terms of realistic warm up speed, but will get you closer quicker, then can fine tune after

[jondee86]

Depending on your ECU, you may have other corrections that affect cold start. Besides coolant
temp enrichment, I have air temp and post-cranking enrichments, as well as the ISCV adjusting
idle air. And ignition timing has a big effect on cold idle... a few extra degrees can make all the
difference. It is a real balancing act

Cheers... jondee86