Have they updated the ECM to the latest?

Mine seems to be adjusting at fill ups properly.

2010 Sierra hard to start when cold (not freezing just cool)

 

Is this being caused because you are switching between E85 and unleaded?

 

Only thing I have is 10 percent ethanol here... Its in all the gas...the mechanic I deal with was suppost to check on the ECM updates as well... Haven't heard anything...

 

The mechanic said this time is cause of my catch can.. The unmeteted air he said... Im all confused...

 

If it's a proper catch can there is no unmetered air

Sent from my iPhone using Tapatalk

 

The air is "Metered" through the cold air intake at the Mass Airflow Sensor. THat is what meters the air. I see nothing about at catch can that would affect the airflow or it's "metering" and hence screw up the ethanol percentage. The only difference between a motor with a catch can and one without is that a tiny bit of moisture and crank case gunk gets filtered out...it doesnt change the air flow itself.

I have a feeling the mechanic doesn't even know what a catch can is. I would blame the aftermarket CAI before I would blame the Catch Can. Maybe the mechanic was confusing the two.

It also seems like winter is the time when this issue seems to arise the most. I don't have any stats on that, but looking back, it does seem like this issue crops up in waves on the forum and I am thinking weather might have something to do with it.

 

I have no idea where to get updates for the ECM at. The only place close to me is about 45 minutes away... And if there telling me there are no update to perform, how do I argue that? All I know guys is this is the second time I had to reset the fuel /alcohol composition sensor... First time was free... This time was 40...he does give me a break. Big break bit I'm just curious as to or if I'm gonna have to do this every other month now...

Truck only has 35k miles and it's a 13. It baffles me
I thank you for the reply... Just wish I had something solid other then reset this parameter.... I put 87 in at all times... 10 percent ethanol.. Even had it check... The content. A few times... Highest I got was 11 percent...
..

 

I would call around to different dealers and ask about the update. I have a 13 as well, but no issues with the alcohol percentage getting out of whack. I just read mine the other day and it was 10.8.

I guess if I was you, I would be very careful about where i buy my gas. Make sure it is a name brand station like Exon, Mobile, BP, Velaro, etc... Don't go to the Mom and Pop outfits even if they save you a few cents. They don't put in the additives that the big chains do and they don't have the reputation to uphold like the chains do.

GM recommends Top Tier stations and here is a list: http://www.toptiergas.com/licensedbrands/

 

Well to be honest I have no clue if the ECM update they did at the dealer had anything to do with this issue and if it will prevent it from reoccurring. I have no info on what it was....what I did and that is such a crock. Even a cell phone update tells me what is effected. So there is no guarantee that will fix your issue.

Have you had the engine looked over really well for any intake gasket leaks or issue with connection of the intake? If something is wrong with the system....that can throw things off as well. So I was told.

 

Just a thought, if his catch can has an air filter on it (like the one shown below) would this not let air into the system bypassing the MAF?

 

That would not bypass the maf. the maf is in the cold air intake between the air filter and the intake manifold.

 

How did you make and install your homemade catch can?

 

I have no codes.. Runs good.. Just starts like shit... I got it reset Tuesday

 

Was run in line with the pcv. One similar to the picture you posted.. Just no filter...

 

Does this, mean it has to be reset again...?

 

Does this, mean it has to be reset again...?

 

You just had it reset and it is already up to 29% alcohol????? And you are running only E10 gas? If so, something is wrong. I wonder if you have some bad gas or contamination in it. You don't use any kind of fuel additive like HEET gas line antifreeze do you?

 

No... Nothing... Never have... What do you mean contamination? Just got gas today to... 87

 

Any other clues, as to what it could be... Im bout to trade it in... Lol. Only 35k miles...

 

Excess water in the gas, bad gas at the pump, or additives that might be messing with the readings.

 

You might mix some diesel in to help offset the alcohol also. And contrary to popular belief it will nit hurt anything. Ive used it in high compression engines to offset octane rating. And yes I know diesel is rated by pentane. The point is to make the fuel less flammable. And diesel isnt flammable. Which is precisely why they have such high compression, so it will get hot enough to burn. Ive ran it in my sierra also but really needs a but higher compression to be worthwhile. As much as 8 gal per tank and as little as 1. I'd start with 2.5 gal without calculating it for the purpose of ethanol content. If you mix just add the diesel first then gas to mix well. It would be interesting to see someone try in an ecotec.

 

You need to refill your tank with good gas, then do a reset and update. Readings will continue to be high if the etank doesn't get better gas. Also alcohol percentages are calculated through the O2 sensors as there is no physical sensor in nnbs trucks. Here's my bill from the dealer to reset and update ecm. And that's in cdn dollars.

1

• talon118
• Jan 6, 2018

 

You might mix some diesel in to help offset the alcohol also. And contrary to popular belief it will nit hurt anything. Ive used it in high compression engines to offset octane rating. And yes I know diesel is rated by pentane. The point is to make the fuel less flammable. And diesel isnt flammable. Which is precisely why they have such high compression, so it will get hot enough to burn. Ive ran it in my sierra also but really needs a but higher compression to be worthwhile. As much as 8 gal per tank and as little as 1. I'd start with 2.5 gal without calculating it for the purpose of ethanol content. If you mix just add the diesel first then gas to mix well. It would be interesting to see someone try in an ecotec.

I had never heard of anyone running diesel in a regular engine before for any reason in any amount. I would like to hear more about it.

 

Here's another idea also. Get a gallon of the same fuel that continues to read high. Let it sit still for a month. It will separate and you can see if it looks to be over 10%.

 

I say just go to a station that you can trust...for sure one other than the one you have been using. That station might be mixing in more ethanol than 10% to "water it down" and pinch a few pennies.