Cadillac CTS-V Forum banner

1 - 9 of 9 Posts

·
Registered
Joined
·
136 Posts
Discussion Starter #1
Since the pulley and flex install I've had a intermittent hard cold start issue. Do you tuning gurus think this could be tuning related? Only does it on a cold engine start after sitting for awhile. I thought I had it solved with a very small fuel leak I found. Showed up again after switching back to flex for awhile. Although it did it before when I went back to 93.

I'm out of town for awhile so my tuner can't look at it now. He suggested I check battery voltage to make sure I'm over 12V at start up and I am. Here is the video. Any ideas?? Thanks.

https://youtu.be/IxU_CvB1xHE


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
2,038 Posts
Does it only happen when you have significant amount of Ethanol % in the tank? Because Ethanol in general is much harder to ignite (part of the reason it is better against detonation).

I know it is a very common problem for hard cold start on E85 when your tuner doesn't exactly know what he is doing. My old friend and tuner for my subaru was always fixing people's E85 tunes because we were in the great white north of MN. With proper tuning I never had a problem with hard starting on E85 even in the dead of winter below zero.

I have no idea what you have to change to fix it but I know it is a common problem.
 

·
Registered
Joined
·
136 Posts
Discussion Starter #3
Does it only happen when you have significant amount of Ethanol % in the tank? Because Ethanol in general is much harder to ignite (part of the reason it is better against detonation).

I know it is a very common problem for hard cold start on E85 when your tuner doesn't exactly know what he is doing. My old friend and tuner for my subaru was always fixing people's E85 tunes because we were in the great white north of MN. With proper tuning I never had a problem with hard starting on E85 even in the dead of winter below zero.

I have no idea what you have to change to fix it but I know it is a common problem.
Well it first happened on E62 and I switched back to 93 gas and it continued. I fixed my small leak and switched back to E and all seemed good. Made a 400 mile drive all on E and had the problem yesterday on start up.

Of course had no issues on initial tune but car was hot. My tuner of course wants to look at it and address the problem but I'm just out of town for about 3 weeks. I have faith that if it's a Tuning Issue then he can fix it. He tunes alot of Vs on E.

Just wanted to get others opinion.


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
2,811 Posts
Tri-texan can write you a novel about this I'm sure.

Very likely a tune issue and not enough 'cranking fuel' when cold.

But who knows, if the tuner is well versed in V tuning, you'd think they would have this figured out.
 

·
Registered
Joined
·
618 Posts
It is easily corrected via tune. It is in the open loop fueling parameters. You have to be careful though -- it is hard to test the colder values unless you have a way of getting your car down to those low temps. A small change can make it where your car floods out during cold start. It's a tricky business. However, you can see from the pictures below that there are parameters for gas values vs alcohol values. It uses a weighted average between the gas table and alcohol table depending on the percentage of alcohol being reported by the sensor. You could start by having your tuner add say 10% to the alcohol table.

 

·
Registered
Joined
·
136 Posts
Discussion Starter #6
Tri-texan can write you a novel about this I'm sure.

Very likely a tune issue and not enough 'cranking fuel' when cold.

But who knows, if the tuner is well versed in V tuning, you'd think they would have this figured out.
Yeah I've read Tri's novel.

That's what my tuner is thinking but I just haven't been able to get him the car to address it.


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
136 Posts
Discussion Starter #8
Were you able to get this resolved? A friend is having similar issues.
Yep just a little more fuel on the crank cycle and is all good now.


Sent from my iPhone using Tapatalk
 
1 - 9 of 9 Posts
Top