Rough idle/ shuddering in idle.

[iboughtatahoe23]

If you buy plugs, check the gaps. They say you don’t have to gap them but almost every one of my AC Delco plugs I bought from Rockauto were gapped at like 15-20, instead of 40. They tell you to return them and purchase new ones but that might take a while, with how many are not correct.

And you can get a gapping tool? Like at an auto store?

 

[iboughtatahoe23]

We had a 2002 flex fuel surburban and when I used E85 it was hard starting and I could tell the starter and battery wouldn't last near as long so I only occasionally ran it.

Hmmm. I don’t notice a difference in starting. I know they aren’t new (battery in alternator in my 2014 Tahoe)

I will get “starter lag” only on the first start of the day (sometimes)

It’s like it will skip or something but it always turns over and the crank isn’t slow. The crank just stutters or something sometimes. And this is only if it’s the first start and or if it’s cold. The battery usually hovers around 14.0V

 

[iboughtatahoe23]

Hmmm. I don’t notice a difference in starting. I know they aren’t new (battery in alternator in my 2014 Tahoe)

I will get “starter lag” only on the first start of the day (sometimes)

It’s like it will skip or something but it always turns over and the crank isn’t slow. The crank just stutters or something sometimes. And this is only if it’s the first start and or if it’s cold. The battery usually hovers around 14.0V

In reference to running e85

Wonder why that would happen for you with e85…. The slow starting?

 

[iboughtatahoe23]

Tahoes are one of the most heavy vehicles on the road, and slow as balls because of it but once they get up to speed its like riding on a cloud and that's where they shine.

The nearest freeway onramp near my house is a 20mph cork skrew onramp and I nearly get ran off the road every time I need to use the freeway because I have like less than 1 football field to get from 20mph to 70mph merging speed after the cork screw and sometimes the semi trucks don't have room to move over for me.

Ya not happening in our boats

 

[iboughtatahoe23]

We had a 2002 flex fuel surburban and when I used E85 it was hard starting and I could tell the starter and battery wouldn't last near as long so I only occasionally ran it.

Wondering how this would happen. And wasn’t aware they did flex fuel in 2nd gens… maybe I stand corrected? Thought it was only 3rd gen and up

 

[iboughtatahoe23]

I’ll keep adding to this thread about my idle as I keep running e85 consistently

 

[Fless]

In reference to running e85

Wonder why that would happen for you with e85…. The slow starting?

An informative read: https://eflexfuel.com/us/blog/do-cars-using-e85-start-in-the-cold

Keep in mind that the models with the virtual sensor may not be reading the alcohol content correctly, and may not apply the correct fuel table.

 

[Onlyone]

And you can get a gapping tool? Like at an auto store?

Yes. There’s a coin type that looks like it has a keychain hole but it’s actually where you can bend the tip without touching the delicate parts. Don’t use the Slide part to gap, only to check the actual gap. Use the little hole to widen the gap.

 

[OR VietVet]

Yes. There’s a coin type that looks like it has a keychain hole but it’s actually where you can bent the tip without touching the delicate parts. Don’t use the Slide part to gap, only to check the actual gap. Use the little hole to widen the gap.
View attachment 403334

They have stacks of those at AZ stores.

 

[Meathead16]

I admittedly didn't read through all the posts so this may have been mentioned but how's your motor / trans mounts?