[e320Fred]

How do you just adjust 2nd to 3rd upshift (94 E320 sedan) when I want it to shift sooner... seems to be revving higher and then shifts for about a long second, versus a quicker and lower rpm transition... Gas mileage has suffered and I think this is the issue.

the trans was soft rebuilt 3k ago... 3rd to 4th shifts perfect, never seen 1st (good for45 degree inclines, I guess ...

 

[Clarkz71]

seems to be revving higher and then shifts for about a long second, versus a quicker and lower rpm transition... Gas mileage has suffered and I think this is the issue.

You're not talking about the shift delay that's normal until the engine temp comes up, are you?
It's to warm up the catalytic conveter faster.

Or does this delay happen all the time?

The control pressure cable will affect the shift timing of all gears.

 

[Clarkz71]

From the FSM............



Transmission upshift delay

In order for the catalyst to reach its operating
temperature faster, the no load or partial !oad
2 - 3 upshift is delayed for a maximum of 90
seconds after engine start at engine coolant
temperatures between 0°C and 40°C. Therefore.
the upshift takes place at a higher englne rpm.
The delayed upshift controlled by the engine
control module HFM (N314) via the upshift delay
switchover valve Y3/3. see group 14.
The engine control module processes the
following information for this purpose:

Engine coolant temperature,

Vehicle speed signal (via CAN),

Transmission range 'D" (via CAN),

Elapsed time after start.

 

[e320Fred]

You're not talking about the shift delay that's normal until the engine temp comes up, are you?
It's to warm up the catalytic conveter faster.

Or does this delay happen all the time?

Delay happens at all temperatures. Symptoms sound like the warm up delay module is not disengaging?

 

[Clarkz71]

Possible, either that or the vacuum can at the transmission for the
bowden cable.

Disconnect the vacuum line at Y3/3 and plug it. See if that affects it.

The signal comes from the HFM module, but Y3/3 could be stuck.
Check it for power.

 

[e320Fred]

Possible, either that or the vacuum can at the transmission for the
bowden cable.

Disconnect the vacuum line at Y3/3 and plug it. See if that affects it.

The signal comes from the HFM module, but Y3/3 could be stuck.
Check it for power.

The bowden can was replaced at rebuild but I will try plugging the Y3/3 vacuum line and checking power to it... I'll post progress after I get to test it.

Thanks Clark...

 

[e320Fred]

I think my upshift 2 to 3 issue is the flare symptom that is remedied with valve body kit... link to topic

http://www.benzworld.org/forums/w124-e-ce-d-td-class/1825194-transmission-issue-after-service.html

not sure if my 94 E320 sedan takes same part number though?

 

[e320Fred]

Possible, either that or the vacuum can at the transmission for the
bowden cable.

Disconnect the vacuum line at Y3/3 and plug it. See if that affects it.

The signal comes from the HFM module, but Y3/3 could be stuck.
Check it for power.

You are good, Clark! Checked line and found a cracked elbow vacuum line connector. fixed it. now going to test out today.... Thanks Clark!

 

[Clarkz71]

Well, that may cause a code, but I don't know if it's the problem.

Keep us posted.

I circled the fitting to plug for anyone that wants to disable the shift delay.

 

[e320Fred]

Well, that may cause a code, but I don't know if it's the problem.

Now that you mention it, I remember seeing code 26 awhile back... after test I'll check codes... to be continued...

Thinking current symptom (2 to 3 rpm upshift) is the flair issue remedied by with a spring kit. If so, I think it's a simple fix, drop pan, remove side plate from valve body, replace spring....right?

 

[Clarkz71]

Flare and delay are two different things.


.

 

[e320Fred]

Flare and delay are two different things.


.

Not sure if I have the right nomenclature?

The car is upshifting too late at 2750-3200 rpm (versus 2000-2500 rpm-- delay) with rpm spike and drop (flair-a long second) at that point.

I might video my dash with a good engine/car audio showing symptom then post.

Also, seems a slight change (sooner) in upshift after fixing vacuum tube elbow fix--after a day of work driving....

 

[Clarkz71]

Not sure if I have the right nomenclature?

The car is upshifting too late at 2750-3200 rpm (versus 2000-2500 rpm-- delay) with rpm spike and drop (flair-a long second) at that point.

I might video my dash with a good engine/car audio showing symptom then post.

Also, seems a slight change (sooner) in upshift after fixing vacuum tube elbow fix--after a day of work driving....

No, you have a delay in shift.

A flare is when the rpm rises suddenly and drops back down during a shift.