Transmission morning sickness?

[Q45man1]

For the last few days (morning only) my transmission is experiencing some weirdjerking when you put into gears.

Issue. I start my car and I've noticed the tach goes up to 2K rpm, and when I put into reverse the trans jerk badly and it feels like it's coming apart. When I shift to D it does the same thing. But when it get to speed and engine start to warm up, the problem disappears. It happened to me twice last week and this morning.

I had trans flush, gear oil and fuel filter changed last Saturday. The dealer also checked my ECU for error codes and nothing came up. The car has 119K miles. It is well maintained with service history on file.Today, I have unplugged my TCU and bolted back in tight. I've checked my ECU for error codes and nothing came up.

Any help is appreciated.

[quicksilver03]

any trans service prior to this flush? are you the original owner?

[Q45man1]

It had a pan drop 11K miles ago. All fluids are fresh.

[goody90q45]

I start my car and I've noticed the tach goes up to 2K rpm, and when I put into reverse the trans jerk badly and it feels like it's coming apart....... But when it get to speed and engine start to warm up, the problem disappears.

It sounds like the problem is not with your transmission but with the engine warm up idle speed. 2000 rpm is awfully high, especially in SoCal where it's not cold at night. Even in Sacramento my Q starts at about 1500 rpm or less, settles down to about 900 rpm after 20 seconds and a tap on the gas pedal, and idles at 650-700 rpm after warmup. If you're shifting out of park at an rpm above about 1000 it's going to jerk the transmission. What's your idle rpm with a warmed up engine?

[Q45man1]

Mike-My idle is between 750- 800 rpm at warmed up engine. I went back to my 95 TCU. My trans is running smoother with this on. I have to check my FSM and let you know.

Thanks,Percy

[maxnix]

Check the throttle cables on top. There is slack designed in, and if removed, the idle goes haywire.

[Q45man1]

Brian,I have to adjust to slack a little bit. We'll see tomorrow.Thanks,

[3Q Jay]

true, dat. but, i did check that on sunday, and there was plenty o slack.

Percy, next tfew times in the morning, you might check to see if the throttle arm is resting on the fast idle cam (that little almost nautilus shell flange i was showing you). if it's not resting on that, then something is holding the throttle plate slightly open.

[Q45man1]

Jay-I'll do that and thanks again.

[Q45tech]

I have to clean my throttle housing to spotless every 12 months to remove the tiny bits of oily vapor dirt at the bottom near the 2 signal vents...........this shows up as increased IAC duty cycle and a change in rpm and the slope of rpm during warm up.

Expose the TB and look with a flashlight when the plate is cracked open any dirt [blackness] requires removal.

As the miles and blowby [cold start warmup] builds up - maintenance frequency increases.

Same with IAC interals dirty oily sticky film changes the as designed operation.

With 120k and all those years the AT is probably ready for a Lubeguard Red infusion.

[PachoC]

Is it "normal" that after you clean the TB you need to adjust the idle speed (usually bring it down) using the IAC needle/plunger?

[96Qowner]

Common, yes, not sure about normal - doesn't seem like you should have to.

But common, yep.

[Q45tech]

Assuming that the IAC manual bypass is set correctly at the factory it should not need changing - adjusting ever! Unfortunately lazy techs or cheap owners don't keep the intake path as brand new every year.............the easy quick fix is to constantly adjust the manual bypass valve.............then after cleaning adjust it back again forever to nauseum.

The IAC duty cycle tells you somethings is off by being out of 15% range.

The ecu tries to maintain idle rpm by changing IAC duty cycle and or adjusting ignition advance and injector open time..........If it adds IAC it adds injector time.

When you add IAC duty cycle you take away from the dynamic range during cruise and coast down............even ac control suffers.

[PachoC]

So I guess this means: Clean the plenum and the IAC at the same time you clean the TB....

[maxnix]

So I guess this means: Clean the plenum and the IAC at the same time you clean the TB....

And the EGR valve. Might as well do the KS, harness and under plenum rubber while you have it off.

Every 100K or ten years, which ever is first.

[Q45man1]

After thoroughly cleaning my TB the night before, the idle speed went very smooth. Driving to work this morning while the freeway (scary moment), I have noticed some hesitation. I pushed the gas pedal and it get worse, and it feels like it's going to die. Good thing I was pretty close to work and I knew it could be my MAF or something in my fuel lines.

During my lunch break, I pulled out my spare MAF and installed back in. It coudn't be my fuel pump since I had it replaced 3 months ago and my fuel filter is brand new. Start the car and drove around the block and hesitation went away.

It was running the way it should be- smooooth. We''ll I'm glad I have some spares (ECU, FPCU, MAF) in my trunk ready to tackle simple job like this.

Thanks to all for the assistance.