Better L400 urban mileage in second ("Hold") gear?

[pajerry]

Yeah, thats pretty much what I figured.

I found that the 33's actually improved the gearing some so it shifted at more appropriate points, and keeps the rev's while at 110kmph down to around 2300 or so, which is nice.

I just found that the shifting between 3rd and 5th is a little off. It doesnt hold to fourth for more than a second before either being forced into OD, or back to 3rd. I also noticed it feels like its a little more sluggish off the line this last week, almost as though I were riding the clutch too long in a manual. Hopefully I can solve both with a little adjustment, and hopefully the latter problem isnt the torque converter or something major. This is my first Auto.

I've been getting crappy gas mileage the past month, and Im slowly working through these things one by one.. TPS and kickdown tuning in the morning, then the fuel filter first thing monday. Im hoping to get it all tuned up before my drive to Kelowna for Xmas this week.




By the way, do you remember what voltage you settled on while setting the TPS with 33's. I'll start at .8V, but just in case you found a huge difference.

[jessef]

I can't say I remember for sure but I think it was .7

[pajerry]

Wow, I can actually pull up a hill in OD without it hopping gears!!

Now, the kickdown cable.. how much did you adjust it each time? A mm or two? More, less? Which way has what effect?

I don't have a whole lot of time for trial and error today, so Im hoping to make a big difference with one or two adjustments before I hit the road tomorrow morning.

[mararmeisto]

tonydca: It would be better for you to turn overdrive off while driving about in the city (instead of turning on Hold). The two functions work differently, for different reasons. The one you are looking for better response/efficiency in town is the overdrive switch.

Overdrive is like a fourth gear for a 3-spd automatic, and I'm assuming the L400s have a torque converter in them also (same as the L300s) which is kinda like a fifth gear (although slightly different). The underlying principle is to get the gearing as high as possible when at speed and to prevent it from uncoupling down to a lower gear (overdrive and torque converter, respectively).

In the city, I find I generally don't get above 62-65 km/h which is when overdrive and then the torque converter usually kick in. The problem is, when on the highway this is when I'm still accelerating and need the extra revs to help get up to speed! This is a double-problem when there's a bit of an incline.

Finally, when towing, it is generally best to keep the overdrive switched out (nearly all automatics recommend this in the owner's manual). Reason being is the torque converter is set up for the weight of the vehicle, not the weight of the vehicle and a trailer (changes the acceleration equations).

[tonydca]

Actually, marameisto, my problem was that the tranny was holding the lower gears far too long before upshifting. The misadjusted TPS made the van think I had my foot deeper into the throttle that I actually did, so now it upshifts much earlier and at a lower RPM (on light throttle) for smoother shifts.

My goal was to be able to drop it into the highest gear practical when I am just loafing along on the level. Switching the OD off will keep it at unnecessarily high revs (I think).

[Van Diesel]

What you say about adjusting the TPS for smoother shifts... My van frequently shifts 'hard'. You can really feel it jerk into the next gear; it pulls forward as the gears engage. It's as if it were a standard transmission and I let my foot off the clutch really suddenly. (Downshifting is normal.)

Will adjusting the TPS fix this?

Thanks.

[tonydca]

What you say about adjusting the TPS for smoother shifts... My van frequently shifts 'hard'. You can really feel it jerk into the next gear; it pulls forward as the gears engage. It's as if it were a standard transmission and I let my foot off the clutch really suddenly. (Downshifting is normal.)

Will adjusting the TPS fix this?

Thanks.

dbox -

I found on mine that it was holding onto lower gears too long, shifting at around 3K rpm all the time, and it was virtually impossible to feather the throttle to make it shift lower. The high-rev shifts were very jerky. My TPS was originally reading around 1.4V, and dialing it back to 0.80 V made a huge difference in smoothness of shifting.

HTH,

Tony.

[pajerry]

I'll second that. Although it still needs work. I think I have to play with the kickdown cable as well to get it runnign through all the gears smoothly and around 2500 rpm. right now I still have to get it to 29-3000 and 75kmph before OD kicks in. It would be nice if it could kick in when Im going slower and steady with no incline so it doesnt have to rev as much and waste energy.

I love this truck, but its easy to hate...

[peterh]

There is another mod you can do to the TPS - http://delicaclub.com/viewtopic.php?t=21029&highlight=

I've had this setup now for quite a few weeks and find I dial it depending on mood.

BTW, I used to use the "hold" allot before I did this mod........

Cheers,

[jessef]

Back to the 'HOLD' topic.

After a few weeks, I have not noticed a better or worse MPG with or without HOLD enabled.

The only thing that is noticeable, is the smoother start off the line and a bit better pickup on acceleration with HOLD enabled due to the turbo working sooner.

It's great in the city.

I just wouldn't leave it on in hilly areas.

[peterh]

Back to the 'HOLD' topic.

After a few weeks, I have not noticed a better or worse MPG with or without HOLD enabled.
The only thing that is noticeable, is the smoother start off the line and a bit better pickup on acceleration with HOLD enabled due to the turbo working sooner.
It's great in the city.
I just wouldn't leave it on in hilly areas.

Same for me - no better milage, the car just drives so much smoother and you get to use the torque of the motor instead of revs. I haven't used hold since I added my mod but I still turn off the over-drive around the back streets and where I want a little more engine breaking........

[tonydca]

Back to the 'HOLD' topic.

After a few weeks, I have not noticed a better or worse MPG with or without HOLD enabled.
The only thing that is noticeable, is the smoother start off the line and a bit better pickup on acceleration with HOLD enabled due to the turbo working sooner.
It's great in the city.
I just wouldn't leave it on in hilly areas.

Same for me - no better milage, the car just drives so much smoother and you get to use the torque of the motor instead of revs. I haven't used hold since I added my mod but I still turn off the over-drive around the back streets and where I want a little more engine breaking........

Jesse, I don't know the inner mysteries of the van's ECU, but I suspect the Hold button overrides the TPS, forcing a shift at lower rpms, regardless of throttle position.

That's why it made such a huge difference for me with my misadjusted TPS. With things put right, I now notice very little difference on takeoff between Hold and Normal mode. On light throttle it shifts around 2K in both gears. Great around town.

Of course now, I seem to be losing power from a leaky PRV ( I think... )

And Peter, I'm very tempted to call "Photoshop" on your mod there... Got any more pics?

[peterh]

And Peter, I'm very tempted to call "Photoshop" on your mod there... Got any more pics?

No worries - it is photoshop'd.... There was a guy in oz a few years back building a stretch delica (don't think it was ever finnished tho) but with only one set of rear wheels. I did this to see what it might look like and I liked it The photo did cause some discussion on the UK Deli site a while back tho so I titled it "Photoshop'd" to save them any more any more stress or confusion

I think the mod would be achievable but not sure how practical. We get a few 6 wheel conversions here - utes and Landcruiser troop carriers mainly, but I think the Deli would end up being a bit long for off-road work

[Van Diesel]

Thank you all for the tips on this one. I adjusted my TPS as low as it can go, which is still above 0.8V. The shifting is smoother. But...

When I compare the shifting of this auto transmission to that in my girlfriends Civic, it's still really rough. In her car, if it wasn't for the sound of the engine you wouldn't notice the shifting. In the Delica, I'm still getting the jerky shift (although less jerky).

Could fiddling with the kickdown cable (or anything else) help this? Do I need even more adjustability as in Peter's mod with the in-cab potentiometer?

[tonydca]

Thank you all for the tips on this one. I adjusted my TPS as low as it can go, which is still above 0.8V. The shifting is smoother. But...

When I compare the shifting of this auto transmission to that in my girlfriends Civic, it's still really rough. In her car, if it wasn't for the sound of the engine you wouldn't notice the shifting. In the Delica, I'm still getting the jerky shift (although less jerky).

Could fiddling with the kickdown cable (or anything else) help this? Do I need even more adjustability as in Peter's mod with the in-cab potentiometer?

Is it jerky because it is still shifting at too-high revs, or is it just jerky overall? If I put my foot into it, there is only so much the tranny can make up for.

And I doubt I'll ever see it shift as smoothly as my old Toyota. But it's a heck of a lot better than it was.

I can't comment on the kickdown cable, as I haven't looked into how the two (cable and TPS) are related. I've been too busy installing a boost gauge