What controls cold start?

[edwinm3]

What specific engine component makes the engine cycle through the cold start function? I know software can turn it on and off but I ask because my car is not cold cycling like it used to. It tries to cycle for a couple of seconds and then it idles normal. I have a tune but the cold start was kept on.

[BMRLVR]

Pretty sure that the DME uses coolant temperature to decide wether to enable cold start or not.

[M3takesNYC]

You would think but countless times I have turned my car off for a few minutes and then restarted after a quick trip in the store or something and the cold start loudness happens and the car is still fully warm so I wondered this same question myself.

[edwinm3]

Originally Posted by M3takesNYC

You would think but countless times I have turned my car off for a few minutes and then restarted after a quick trip in the store or something and the cold start loudness happens and the car is still fully warm so I wondered this same question myself.

Yeah exactly mine did the same thing. I just tested the secondary air pump and it is good but still no cold starts

[BMRLVR]

Originally Posted by M3takesNYC

You would think but countless times I have turned my car off for a few minutes and then restarted after a quick trip in the store or something and the cold start loudness happens and the car is still fully warm so I wondered this same question myself.

The coolant temp is probably the main thing but no doubt some other values may be taken into consideration, like oil temp, IAT, catalyst temp, etc

[aussiem3]

Originally Posted by edwinm3

What specific engine component makes the engine cycle through the cold start function? I know software can turn it on and off but I ask because my car is not cold cycling like it used to. It tries to cycle for a couple of seconds and then it idles normal. I have a tune but the cold start was kept on.

Why won't you ask Mike Benvo. He can disable cold start in his stage I tune and I am sure he can tell wheat exactly is involved. I think cold start is all about the cat pre-heating process.

[edwinm3]

Originally Posted by aussiem3

Why won't you ask Mike Benvo. He can disable cold start in his stage I tune and I am sure he can tell wheat exactly is involved. I think cold start is all about the cat pre-heating process.

Yeah I'm hoping Mike can chime in. I'm catless and tuned but the cold start was definitely kept on. No codes or anything when scanned. It sounds like it wants to go through the cycle but it cuts off, weird

[VCP]

why dont you call or email active since you have a tune from them and they can help you out

Originally Posted by edwinm3

Yeah I'm hoping Mike can chime in. I'm catless and tuned but the cold start was definitely kept on. No codes or anything when scanned. It sounds like it wants to go through the cycle but it cuts off, weird

[edwinm3]

Originally Posted by VCMperformance

why dont you call or email active since you have a tune from them and they can help you out

I did that already and they couldn't help because no codes come up. Car runs fine but it bugs me that I know there is something wrong. It's just one of those things

[aussiem3]

Originally Posted by VCMperformance

why dont you call or email active since you have a tune from them and they can help you out

I am not the one with a cycle issue. Read the thread properly before getting a bee on your bonnet.

[aussiem3]

Originally Posted by edwinm3

Yeah I'm hoping Mike can chime in. I'm catless and tuned but the cold start was definitely kept on. No codes or anything when scanned. It sounds like it wants to go through the cycle but it cuts off, weird

Is this a new issue or has existed since the tune and the catless option? The reason me asking is because the DME may be sensing there are no more cats and cuts off early. It might be normal. From your signature I picked up you have AA Tune. So I don't think it will be a good idea to ask Mike about the issue. He might be able to give you some direction but not a fix. Good luck

[IMG]

Originally Posted by BMRLVR

The coolant temp is probably the main thing but no doubt some other values may be taken into consideration, like oil temp, IAT, catalyst temp, etc

+1

[edwinm3]

Originally Posted by aussiem3

Is this a new issue or has existed since the tune and the catless option? The reason me asking is because the DME may be sensing there are no more cats and cuts off early. It might be normal. From your signature I picked up you have AA Tune. So I don't think it will be a good idea to ask Mike about the issue. He might be able to give you some direction but not a fix. Good luck

It's a new issue, cold start was working fine with the tune.
I totally understand what you're saying about Asking Mike, I was just hoping anyone would help, thread wasn't directed to him.

[edwinm3]

Originally Posted by aussiem3

I am not the one with a cycle issue. Read the thread properly before getting a bee on your bonnet.

Not sure what you guys mean

[aussiem3]

Originally Posted by edwinm3

Not sure what you guys mean

I was reacting to OP, nothing to worry.

[VCMpower]

So who is the OP? Maybe down under you are upside down

Originally Posted by aussiem3

I was reacting to OP, nothing to worry.

[JHFW89225]

I am curious about this too because I have a issue which I just noticed this week and it happens when I start up the car after parking it for around 5 min and I put it in gear and drive off right away. When I do that it sounds harsh like my 335i when it was misfiring... But when I let the car wait for as little as 20 seconds and drive off its perfectly fine.

No idle issue whatsoever... Dinan tune + Akrapovic delete R +