Truck shaking at idle

[Cristyan]

I wouldn't bother. I've ran a few tanks of 89 to check mileage and performance and found a negligible difference, not enough to offset the extra cost. And it certainly didn't make the engine idle any "smoother".

If I was towing heavy regularly like 8k+, I might consider 89. But for daily driving and 5k towing on the weekends (twice a year 8k), I can't tell the difference between 87 and 89.

Thanks for sharing your experience. It's a bit of a mixed bag; on one hand, it's good to know that running the test might not be worth the effort, thus saving time and money. On the other hand, it's a bit disappointing to think there might have been one last potential solution to the issue
Well, the search for the perfect fix continues! Thanks again for your input.

 

[Slutzk]

fuel octane isnt going to make a difference. people on this forum are cringe sometimes. Ive only ever ran 87 in hemis ever. and everyone i know except 1 person off the top of my head runs 89 or 91 (depending on prices in the country hes living in.... California i mean.). he switched to 87 when he got his 2022 and he said it runs... EXACTLY the same with now 45k miles on it. never met anyone running 93. never made a difference from beginning till end of life with the owner. cant tell me other wise, i legit have see it multiple times and no difference. your motor isnt shaking because of fuel. now if your vehical REQUIRES 91-93.... yeah running 87 probably aint smart. but 2 octane levels aint doing crap. if anthing going to high will be worst

 

[23RAM]

Thanks for sharing your experience. It's a bit of a mixed bag; on one hand, it's good to know that running the test might not be worth the effort, thus saving time and money. On the other hand, it's a bit disappointing to think there might have been one last potential solution to the issue
Well, the search for the perfect fix continues! Thanks again for your input.

Apparently I had a bad wire in the harness causing a shake/stumble at first, leading to intermittent missing, to full time misfire on cyl 5 where the injector was not firing like it was dead. Somewhere in the harness a wire or connector was bad and caused the injector to not fire. Mine started with a stumble at stops like it wasn't combusting properly like I had some bad fuel or water in the fuel system.

 

[Fantastipotamus]

Also, just incidentally, check your oil level. My truck developed a weird, vibrating idle not long after an oil change, and it turns out they'd just put in the new oil on top of the old, so i was running double the recommended capacity. Yowza. They fixed/admitted wrongdoing, refunded and gave me a free oil change for next time and made note in case anything went bad (good dealer, tbh). But the only thing that tipped me off was the weird idle characteristics and a tiny bit of extra smoke out the exhaust at idle.

 

[Nascar Tommy]

I agree on idle of 500 rpm seems low to me. I'll have to pay attention next time I'm in mine. Thought it was close to 700rpm.
Checked my idle, it's 650 RPM. I think you should raise your idle a little bit.

 

[Ramhighflyer]

I agree on idle of 500 rpm seems low to me. I'll have to pay attention next time I'm in mine. Thought it was close to 700rpm.
Checked my idle, it's 650 RPM. I think you should raise your idle a little bit.

Idle control is 100% computer controlled, there has not been a ”upping your idle a bit” in 20 years……there is very little to nothing to “adjust” on a modern engine

 

[theblet]

Idle control is 100% computer controlled, there has not been a ”upping your idle a bit” in 20 years……there is very little to nothing to “adjust” on a modern engine

I think you can adjust this with alpha or jscan.

 

[Nascar Tommy]

Idle control is 100% computer controlled, there has not been a ”upping your idle a bit” in 20 years……there is very little to nothing to “adjust” on a modern engine

Yep! I'm old!

 

[Wirerat]

I think you can adjust this with alpha or jscan.

It's takes a unlocked pcm with tune for idle adjustment.