High altitude/cold weather hesitation with MT gears 2 & 3

Food for thought: In my area they blend fuel differently in summer and winter. I have a Chrysler 300 with a 6.4 Hemi and EVERY fall I get some cold start roughness for a month or so and I have attributed it to the seasonal fuel change. It does the same thing in spring. Dead of winter and middle of summer it starts perfectly.

 

You make me feel like a grandpa. I shift at 2000-2400 RPMs, may rev it out to 3k if it's below freezing.

Yeah, summer blend and winter blend exist, and it's why prices typically go up around April/May (and drop ever so slightly around September). I forget the details of it, but it has to do with detonation.

 

2K is too low to shift out of 1st if you intend on accelerating. You need 2500-2800rpm to smoothly accelerate and make 2nd gear work. 3.5 does not like to be loaded at low rpm at all.

 

I probably shouldn't mention that I start in 2nd gear sometimes then.

 

Really? Why? All my truck wants to do trying to start in 2nd is die and be super jerky. I have to slip the clutch big time to get moving enough to finally drop the clutch fully without dying.

 

Because it's not a race car and I'm not in a hurry. I won't start in 2nd if I'm on hill, but if it's flat or especially downhill I nearly always start in 2nd. Blip the gas, off the clutch, and away it goes. Sure it's not fast, but as long as you aren't full throttle it'll manage just fine. If you're too hard on the throttle it'll definitely bog and lurch on you, but if you ease into it, I haven't had any problems.

I've said it before, I would prefer 1st gear be a real crawler gear and 2nd be shorter, but since 2nd is so tall, 1st gear feels absent to begin with - especially since I shift so early.

 

Why would you wanna be shifting at 4600 rpms with normal driving? At 4600 rpms my truck is like a rocket. I shift at 2-3k rpms and there is plenty of torque. I’m not stock, 33” E loads and about 600 of extra weight.

You should really test drive a 3rd gen and see for yourself.

 

Most of the time I shift out of first at 2-2.5k rpms. Usually I’m not in a rush and truck accelerates just fine in 2nd.

When cruising I’m in 1200-1300 rpm range.

 

A rocket?

 

Yes.

 

I have a 3rd gen manual and live in colorado as well. Mine does some weird things in cold weather as well. I definitely feel the "hesitation" from time to time. The thing that really bothers me is the clutch pedal doesn't reset that fast when the truck is cold. It drives me crazy. I know several guys in colorado with the same issues. I've owned 7 manual vehicles and never experienced anything similar.

 

Whoa - I signed up for email alerts on this thread and haven't gotten any for most of these posts... so I assumed the thread died. Sorry about that!

I paid a bit more attention to what was going on the past couple days... The hesitation occurs right at 1,700rpm. I can induce it fairly consistently if I smash the throttle on upshifts below that point.

Unless I'm merging onto the highway or something, I'm coming out of gear at around 2k which means I'm engaging the throttle in the next gear around 1,500. Throughout the summer that worked swimmingly - I could get into the next gear and floor the throttle and I would get smooth delivery until the next shift. Looks like I need to refine my technique a bit for winter driving. If I can reengage the throttle at above 1,700 on an upshift, I'm golden, no matter how hard I mash it, and I can still drop below that as long as I'm gentler with the throttle. That jives with the post above that mentioned shifting at 2,500-2,800. I cut my teeth on pretty torquey rides... '85 BMW 325e and '04 diesel Golf, specifically. Guess I got used to shifting at low revs. Even my 4cyl Outback - which was my most recent manual - worked fine that way though.

I appreciate all the posts, as it does make me feel better about it. Sounds like I really just haven't nailed the technique yet after all!

 

I don’t think I’ve owned an automobile that was happy if I floored it in 2nd gear at 1700 rpm on pavement. That sounds akin to spousal abuse I also have never owned a diesel or a v8.

 

Man, being a n00b on this forum has my head spinning! currently going down the rabbit hole on tuning... wow. That's a deep subject. Anyway, in the course of reading through tuning MTs, I stumbled across the term "rev hang" which I gather has been a big topic on here for MT Tacoma owners.

I didn't have a word for it, but it was the first thing that drove me nuts about this truck and made me have to relearn how to drive a manual! In all my previous MT vehicles, I would float out of gear without the clutch as I let off the throttle and slide into the next gear with clutch (upshifts) or blip the throttle and drop into a lower gear with clutch (downshifts; depends on if I need to be breaking - might clutch out of gear if so). That didn't work for upshifts with this truck because the revs wouldn't fall!

It took me forever to settle into something that works, and it's hard to describe, but I have found a way to eliminate it. If I 'catch' the shifter in the current gear just a bit on the way out the revs fall as expected in between gears. Here's what I tried to do for upshifts when I first got it:

1. put light pull-out-of-gear pressure on the shifter while I'm still on the throttle
2. let off the throttle and apply no clutch - the shifter floats out of the current gear
3. revs fall between gears (<-that never happened)
4. apply clutch as I slide into next gear

That didn't work because of the rev hang, but this does (if it makes any sense):

1. start the pull-out-of-gear motion on the shifter
2. drop throttle as you meet the resistance coming out of gear
3. revs fall
4. apply clutch and slide into next gear

This is hard to describe, and it all happens more or less simultaneously, but it worked for me.

Anyway, not really on topic for this thread, but I was excited and thought I'd blog about it!

 

When you say "apply clutch" Do you mean press in the clutch pedal or engage the clutch? Because it reads to me that you're not using the clutch pedal until the transmission is already in neutral. It also reads as you're riding the clutch a little bit in either scenario.

But yeah, rev hang is a by-product of drive-by-wire and, more importantly, emissions, hence why the tune is a solution - consumers who buy manuals are less concerned with emissions than an organization that is held to standards.

 

It's all a bit hopeless to describe in text I guess... In previous cars I generally wouldn't touch the clutch pedal until I was in neutral on my way into the next gear.

The method that's working for me in the Tacoma has it all sort of happening at once but the key seems to be sliding out of gear such that I catch a hint of resistance on the way out as my foot is engaging the clutch.

'catch' maybe isn't the right word and it makes it sound crunchy and damaging, which it's not. When executed perfectly it's smooth as silk!

There is no riding of the clutch in this house...

 

My 22 MT Taco Sport does the exact same thing. Been driving MT's for 35 years and a lot of them did that. My 14 Hemi Challenger with the MT did the exact same thing too. Not user error on my part considering I can shift smoother than most auto's. Once the engine warms up it should stop doing this. Us old timers call cars like that "cold blooded".