my 3VZ-FE in not behaving

[DJPsystems]

I have an issue that I cannot figure out. The best way to describe it is a lack of low end torque/sluggish exeleration. When stopped completely I floor the gas it feels like a 4 cylinder intill it reaches about 3000 rpm, then the "power" kicks in and it pulls good all the way to redline. I also lost about 2 mpg. This started happening right after I had the transmission rebuilt. I have looked around the engine compartment and everything looks normal. It does not throw any codes. I have replaced:
ECM
air flow meter
plugs, wires, cap, and rotor
distributor
fuel pressure regulator
fuel filter
fuel pump
timing belt
O2 sensors
played around with timing
played around with air flow meter
fuel pressure is withing specs
tps is within specs

Car had around 150k, it now just turned over 200k. This is a 92 ES300. I do not want to throw any more parts at it and I would rather not take it to the dealership. If anybody has any ideas I would gladly appreciate it.

[oldfirebird]

Two guesses:
If it's an automatic transmission, put the gear selector in 2 and run it up to about 35 miles an hour. Can you feel the 1-2 shift? Maybe the transmission isn't shifting all the way down to first?
Or, the variable intake runners may be stuck on long runner? Is the actuator diaphragm torn, vacuum line cracked or disconnected? I honestly don't know how much of a difference that variable intake system makes....

[camry6]

Originally Posted by DJPsystems

I have an issue that I cannot figure out. The best way to describe it is a lack of low end torque/sluggish exeleration. When stopped completely I floor the gas it feels like a 4 cylinder intill it reaches about 3000 rpm, then the "power" kicks in and it pulls good all the way to redline. I also lost about 2 mpg. This started happening right after I had the transmission rebuilt. I have looked around the engine compartment and everything looks normal. It does not throw any codes. I have replaced:
ECM
air flow meter
plugs, wires, cap, and rotor
distributor
fuel pressure regulator
fuel filter
fuel pump
timing belt
O2 sensors
played around with timing
played around with air flow meter
fuel pressure is withing specs
tps is within specs

Car had around 150k, it now just turned over 200k. This is a 92 ES300. I do not want to throw any more parts at it and I would rather not take it to the dealership. If anybody has any ideas I would gladly appreciate it.

Also check the Throttle Valve cable adjustment for the transmission. Sounds like it's starting out in second or shifting to second too early.

[DJPsystems]

The trans is working normally. I can feel the shifts 1-overdrive and lockup. The throttle valve cable is set according to the repair manual, I even played with this adjustment but it does not help.

[Gothmog3VZ]

take off your intake manifold, clean out the acis system, see if that fixes it. Seafoam would also be a good idea

[Jason.MZW20]

Originally Posted by DJPsystems

When stopped completely I floor the gas it feels like a 4 cylinder intill it reaches about 3000 rpm, then the "power" kicks in and it pulls good all the way to redline.

Originally Posted by DJPsystems

The trans is working normally. I can feel the shifts 1-overdrive and lockup. The throttle valve cable is set according to the repair manual, I even played with this adjustment but it does not help.

Sounds like a torque converter stall speed issue or fluid pressure issue.

Fully set the e-brake, also apply full pressure to the brake pedal, start the car, put it in drive, and floor the accelerator. Read the RPM quickly. Obviously, you'll want to be on an abandoned road or some other safe location.

The stall speed should be 2400rpm +/- 150rpm. If the engine turns higher or lower than that, take it back to the transmission shop and tell them the stall speed is incorrect.

[DJPsystems]

I have done the seafoam and cleaned the throttle body with carb cleaner but it did not help. As for the torque converter stall speed the tranny guy swore up and down that the torque converter was the proper one, he said the old one had some kind of color code and that is how they determined the application. Unfortunately he has since gone out of business. But even if it was the converter why would I lose about 2 mpg?

[73sport]

Originally Posted by Jason.MZW20

Sounds like a torque converter stall speed issue or fluid pressure issue.

Fully set the e-brake, also apply full pressure to the brake pedal, start the car, put it in drive, and floor the accelerator. Read the RPM quickly. Obviously, you'll want to be on an abandoned road or some other safe location.

The stall speed should be 2400rpm +/- 150rpm. If the engine turns higher or lower than that, take it back to the transmission shop and tell them the stall speed is incorrect.

If your statement about ithe cars power was "it was fine before" and then it had the trans rebuilt is correct, I'll say Jason nailed it 100%. Not all converters are alike and certainly not all torque converter rebuild shops are alike. Subtle change to the pitch of the stator/impeller inside the torque converter can change the stall speed. If your's dropped, it could give you the feeling of having less power as the engine is not in its powerband as it was before.

That's not to say it doesn't have other issues. We're just saying be advised that this could be roll and it could be changed but it'll require pulling the trans again.

FWIW; in the towing world its common practice to tailor the converter to the load by lowering the stall speed. Same is true of race cars raising the stall speed.

As ammunition, the ECM is programmed to lock the converter at specified car, gear, and engine speeds. Having the correct stall could play a role in how long the converter lasts (likely in a favorable direction this case), could be why it has a lower stall?

What fried in your trans and at how many miles?

[DJPsystems]

I had about 150k when the trans "malfunctioned", the pump was whining and in D when taking off from a stop it would feel like it was in 2nd or 3rd. WHen put in 1st it would take off like it should. The rebuilder said one of the drums was bad, something about the splines where worn and also the pump was bad. Do you think that because of the lower stall speed it throws off something in the ecm programing and that is why it behaves like that?

[Jason.MZW20]

Originally Posted by 73sport

FWIW; in the towing world its common practice to tailor the converter to the load by lowering the stall speed. Same is true of race cars raising the stall speed.

Yep, my 05 1GR Tacoma with the tow package has a stall speed of about 1800-2000rpm, but the engine really doesn't come alive until about 3000rpm. It doesn't feel like a 4 cylinder though, but it's also a 5 speed and not a 4 speed, so it has a very strong 1st gear to get the truck moving.

That's why I mentioned stall speed.

Yours could be a combination of reduced stall speed combined with reduced engine power from wear/tear. Those two combined could make it feel like a dog until it gets up to speed.

[oldfirebird]

The mechanic swears it's the right converter, but did you check the stall speed for yourself like Jason.MZW20 described?
The intake might be as clean as the day it left the factory, but if the actuator is bad or not being actuated, you'll still have a problem.

[oldfirebird]

OK, I just checked into the way the ACIS functions. There's to be NO vacuum at the actuator motor when idling or at low RPM. At high RPM the ECM opens the vacuum switching valve (vsv) the actuator actuates, and off you go.
If your vsv has failed or is getting bogus info from the ECM, you'll get vacuum at the actuator when idling.
Pull the vacuum hose from the actuator, cap the hose off, go for a drive. If you suddenly only have low end torque and the motor falls off at higher RPM, well then you need to do some more diagnostics on the vsv or the ecm.

[Jason.MZW20]

Well a malfunctioning ACIS system wouldn't be a drastic performance change. Most people wouldn't know the difference.

[Luckynumber5]

The acis system wont affect low rpm torque like that, it closes in the upper rpm band to extend runner length.

I doubt this is a stall speed issue, though I cannot rule out bad converter yet. The 3vz makes almost full torque after 2000rpm, this sounds like a fueling issue.

Get one of those cheapo 02 sensor gauges and hook it to one of your sensors and look at what the sensor is reading when the bad behavior occurs. I bet it will read dead lean.

[DJPsystems]

Today I did the stall speed test and it went to about 2300 rpm. I also filled up the gas after doing mostly city driving, I calculated 17.2 mpg. As for the ACIS it did have a bad diaphragm but I had to buy the whole assembly because toyota would not sell me just the diaphragm. I was thinking I had a vacuum leak so I took some carb cleaner and sprayed it in different areas while the engine was running but I did not notice the engine rpm change. I feel like this car is possessed.