# Cold start and warm up enrichment



## L33t A2 (Aug 5, 2003)

Aside from other tuning issues my car will not start in the cold weather. I read a few old threads where need a vr6 mentioned 300% at 32 degrees, 200% at 100 degrees, 100% at 180+
Also if I get it to fire up it stalls out lean after firing up for a couple seconds. That is warm up enrichment correct? I was only able to search briefly. It's been a few months since my car ran. Last time I started it, ambient was 50-60 F and getting hard to start. Now the ambient is 20-30 F


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## L33t A2 (Aug 5, 2003)

Oh forgot to mention. I am running an 87 gti 1.8 8v turbo, wg flapper disconnected until NA tune is solid, stock block with 200k+, metal g60 spacered Hg, g60 head. Running stock ign module and distributor with msns 029y4. MSnS (ms1) from diyautotune.


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## ValveCoverGasket (Mar 20, 2002)

it first uses cranking, then after start + warmup enrichment. you can see when each of these is active in the log file, or at the bottom of the tuning window.

if its dies lean after cranking strong you need more WUE
richer is better once youve got it to catch and fire.


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## need_a_VR6 (May 19, 1999)

Those were %reqfuel for cranking. Warmup doesnt need to be that big, usually. 

How long does it run after cranking? Any way to wire the wideband to be on/warm to watch some cold starts?


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## L33t A2 (Aug 5, 2003)

ValveCoverGasket said:


> it first uses cranking, then after start + warmup enrichment. you can see when each of these is active in the log file, or at the bottom of the tuning window.
> 
> if its dies lean after cranking strong you need more WUE
> richer is better once you've got it to catch and fire.


Thanks VCG, def going to increase both, starting is hard enough and then it dies immediately after.



need_a_VR6 said:


> Those were %reqfuel for cranking. Warmup doesn't need to be that big, usually.
> 
> How long does it run after cranking? Any way to wire the wideband to be on/warm to watch some cold starts?


Okay thanks Paul, I wasn't sure if both the cranking and WUE _both_ needed to be jacked up.
It will fire up if I'm lucky, but dies immediately after letting go of the key on the first cough of the engine.
But once is enough, each time I crank the engine over getting it to fire up it will take less cranks.
Then run a few seconds longer until I can feather the throttle enough to keep it running around 2k rpm.
I usually hold it there for about 30 seconds and slowly lift throttle until the idle holds around 600rpm and I let it run for a few minutes at idle which will eventually settle around 850rpm warm.

I have an innovate wideband, the one where the gauge is the controller, I forget the model number.
I have to re wire a few things anyway, been driving it with a rat nest of sorts above the clutch pedal for too long.
I appreciate your input, I'll wire the O2 so that It stays on during cranking, right now its triggered off one of the circuits that opens during cranking so after the engine starts running it triggers on into heating mode for 30 secs.


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## wrbusa (Jun 13, 2007)

It doesn't sound like you are running any type of idle valve? Idle valves will help cold starting, but aren't totally necessary. They tend to give you a little more room for error in the cold start parameters.

for cold starts/warmup the trick is to get fuel/air matched up within a couple %. I was frustrated by this when setting mine up, and here's what I learned:

If it's not catching, start with cranking pulse. If it wont catch unless you're cracking the throttle, you have too much fuel, so dial it back until it catches without throttle. If it won't catch even with throttle, you have too little fuel, go up in cranking 5% at a time until it fires. This is step 1, do it first before moving on.

Once it catches, runs for 1-2 seconds then dies, start with ASE %. It's a little bit of guess work to determine if it died lean or rich, since likely the wideband isn't reading yet. I like to start lean and add 3% or so at a time until it goes for more than a few seconds.

If it catches, runs for 3-5 seconds then dies lean, add more ASE taper. I found longer taper times help when cold, but I'm running e85 which is a different beast.

Dial WUE as it idles itself up to temp. Watch the AFRs, but really just give it what it wants to idle smoothest all the way to operating temperature.

Doing this you should have all but the coldest temps worked out in a few days or so.


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## ValveCoverGasket (Mar 20, 2002)

wrbusa said:


> Doing this you should have all but the coldest temps worked out in a few days or so.


and turning it off and restarting every ~10 deg or so during the warmup cycle helps speed up the tuning as well. 
though you really only get "one shot" at firing it up from dead cold every 10-12 hours, but you can get close-ish just turning it off and firing it up again.


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## L33t A2 (Aug 5, 2003)

*FV-QR*

I never said thanks, but thanks guys, the car fires up without having to touch the gas pedal, idles around 300-400 rpm, and I just wait a few minutes and it slowly warms up and the idle raises to 800-900. After driving it 15 minutes it idles around 1100 or so. Looks like I am going to start messing with the ISV, I want it to idle around 900 when fully hot but it wont start with the idle screw turned down that low.

I read a topic in the Mk3 or 2.0 ABA section a while ago with people saying they run 30*-32* total timing at WOT. Is this true for most 8v engines? I have my ignition map tuned for 30* at WOT starting around 3000 rpm all the way up to redline. It does move but doesn't feel as fast as when it was running CIS. It also seems like I run out of power before 7000. I'm not sure if this is also because I lowered the compression from 10:1 to around 8.5-9:1 and I'm now running a stock g60 cam instead of the gti cam. I don't have extra money laying around for someone to spend a day tuning my car on a dyno or I would. The car is fun to drive, I just feel like there's a little more power hidden in the NA section of my tune. I haven't hooked the wastegate up yet.

Bottom line it's a 1.8L 8v counterflow, around 8.5-9:1 compression, g60 cam... like a g60 engine with higher compression, better rod ratio, and no boost yet. How much timing can I throw at it? I run 93 octane, I'm at sea level. What is a good rev limit? It keeps going up to 7k if i keep the pedal mashed but my butt dyno is telling me the power drops off after 5-5.5k


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## ValveCoverGasket (Mar 20, 2002)

you could try bumping the spark up some, though youre about at the limit of what id feel is safe street tuning... but your lack of pep is more likely (IMO) due to the smaller cam and lower c/r.
one of those on its own would have been enough to neuter it, doing both is sure to slow it down


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## Prof315 (Jan 5, 2009)

You can try bumping the timing up a bit (2-4 deg) but no matter what you are going to be a bit sluggish at high end with that compression ratio and cam.


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## need_a_VR6 (May 19, 1999)

Unless there is a specific reason to run the G60 cam right now, get it out of there and put in at least a stock or cheap aftermarket cam.


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## L33t A2 (Aug 5, 2003)

Okay, since I don't have money for a new cam right now, and the g60 cam was put in for intentions of boost friendliness, it looks like I'm at the point where I hook up the wastegate and start throwing some boost at it. Thanks for all the replies. I'll check back in soon.


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## L33t A2 (Aug 5, 2003)

wrbusa said:


> It doesn't sound like you are running any type of idle valve? Idle valves...tend to give you a little more room for error in the cold start...
> ...start with cranking pulse. If it wont catch unless you're cracking the throttle, you have too much fuel, so dial it back until it catches without throttle. If it won't catch even with throttle, you have too little fuel, go up in cranking 5% at a time until it fires. This is step 1, do it first before moving on...


Thank you, I need to focus on this, I've been getting stranded during hot restarts.


wrbusa said:


> Once it catches, runs for 1-2 seconds then dies, start with ASE %...I like to start lean and add 3% or so at a time until it goes for more than a few seconds...If it catches, runs for 3-5 seconds then dies lean, add more ASE taper. I found longer taper times help when cold...Dial WUE as it idles itself up to temp. Watch the AFRs, but really just give it what it wants to idle smoothest all the way to operating temperature...


Thanks again, the tips really help me, I find that all this information is out there but I never seem to find it in my searching right away. 


ValveCoverGasket said:


> ...restarting every ~10 deg or so during the warmup cycle helps speed up the tuning as well...you really only get "one shot" at firing it up from dead cold every 10-12 hours, but you can get close just turning it off and firing it up again.


I will start doing this, I find that I can get the car started fine in the morning. On a hot restart I'm screwed, and when the car sits a couple hours but still kind of warm I have to fire it up 3-5 times before I can feather the throttle to an idle.


ValveCoverGasket said:


> you could try bumping the spark up some, though you're about at the limit of what id feel is safe street tuning...your lack of pep is more likely due to the smaller cam and lower c/r...one of those on its own would have been enough to neuter it, doing both is sure to slow it down





Prof315 said:


> You can try bumping the timing up a bit (2-4 deg) but no matter what you are going to be a bit sluggish at high end with that compression ratio and cam.





need_a_VR6 said:


> Unless there is a specific reason to run the G60 cam right now, get it out of there and put in at least a stock or cheap aftermarket cam.


I call it learning from experience, I should have researched the cam profiles a bit more before choosing the g60 over the stock gti cam. 


L33t A2 said:


> Okay, since I don't have money for a new cam right now, and the g60 cam was put in for intentions of boost friendliness, it looks like I'm at the point where I hook up the wastegate and start throwing some boost at it. Thanks for all the replies. I'll check back in soon.


I finally saved up and had a free moment to figure out my boost piping. The silicone hoses etc. have been ordered. I'll update with some pics hopefully the next time.

On a side note, would anyone share with me their cranking settings page with the pulse widths table? If so, what size injectors are you running?
Also is there a free hosting site I can upload my msq or vex/table files to for sharing?


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