2haloz

1999 GS300

When my car has reached operating temps, whenever I am driving, if I hit a hard sudden stop, my car surges and either wants to stall or does stall unless I feather the gas. Mind this does not happen until I after warm up. Up until that point the car will not drop RPMs below idle which is about 700. My idling is pretty steady and normal. This issue has gone from a minor surging once in a while to a clockwork issue after warm up. From a complete cold start in winter weather I get very sluggish response until the car warms up.

It does not throw a code whatsoever. Zilch.

I have done the following:

Taken off and cleaned TB

Changed plugs and wires

Cleaned original MAF and also replaced with another working used one

Ran vehicle without MAF - still stalls

Replaced PCV valve

Cleaned OCV solenoid filter

Unplugged TPS and it still will stall in limp mode at a hard stop

Unplugged IAC (throttle motor) and still stalls in limp mode

I have yet to replace ignition coils or 02 sensors as they are expensive to just run around throwing money on, and I have yet to justify doing so without a code. But those are possibilities no?

I also just picked up the my car from the shop and they were of no help and could not figure it out. They serve free diagnostics, but I they looked slammed and so I think they just didn't really try because it wasn't economical to do so when they had other cars piled up. Plus I have had issues with them needing me to bring my car in twice to observe that my water pump was bad despite the fact that belts were squeeling and the bearing was shot. They basically changed a tensioner pulley for no reason before they figured that issue out. So I have very little faith in their competence.

I'm starting to look towards break booster and vac lines? Could that do this?

I'm really not sure where to go with this. I would really appreciate some insight. If there is any other information I can provide please let me know.

2haloz

No ideas? Anybody? This is driving me bonkers.

Deadpool88

Well, all these issues and no CEL makes me want to ask if your CEL light is workings. You've actually had it hooked to an OBD scanner right?

2haloz

Its one issue. Stalling at hard stops after warming up. This list is all things I have tried to do to fix the issue.

Yes I can make it throw a code and light up CEL if I for example unhook TPS and start the car. It has been hooked up to an OBD scanner and there are no codes.

2haloz

OK. So I have made a discovery and would like to know if this could be the culprit...

When I'm under the hood and hit the throttle cable, I get a loud clear hissing sound. Its not intermittent. Every time. It is coming from somewhere around between the throttle body and ABS unit. Trying to figure out if this is maybe a gasket. I for sure have a leaky valve cover. But this sounds like its coming off of a hose.

Could this cause stalling at hard stops? I would imagine a leak would create an issue regardless of the car being warmed up or not? Or would the logic be that during warm up loop ECU is telling it what to do, and then after warm up the car relies in sensors thus the leak then creating an issue?

2haloz

Also I am thinking maybe torque converter... But would a failing TC do this only at operating temp?

marshun

sounds like a fast idle valve. idunno what toyota calls their version. hop that helps

LALEX1

iTrader: (22)

Have you checked your motor mounts? Could it be that there is heavy movement when braking hard because the mounts are bad, therefore possibly the movement causing it to stall?
Just throwing things out there

2haloz

I would consider this except for the fact that when I throw it in neutral and slam the brakes, the car does not stall.

I know I for sure have a leak. It hisses pretty loud when I hit the throttle cable. But my car is more prone to idle low so I'm having a hard time understanding how this could be a vacuum issue. However if I reset the ECU it idles extremely high (2k range in park) until I restart the car. Then at that point maybe ECU idles lower to compensate perhaps? When I changed out my plugs they were fouled and black on the tips which leads me to believe the car was running lean.

2haloz

I don't think 2gen has an idle valve. From my understanding it is controlled by a throttle motor which takes the place of IACV.

2haloz

Screw it. I'm obviously not competent enough to figure this out. Dropping it off at Stevenson Toyota today. I'll report what they find when they are done for the future if somebody else experiences a similar issue. I'm interested to know how far off the mark any of my conjectures are.

Deadpool88

Look up the "rough idle issue" thread in the 2GS section. Although your car seems to not be throwing codes which is crazy. I swear mine will throw a code for my drink being empty.

My car had a similar issue (granted it through a code) and it was the oil control valve (VVTi solenoid). Once the car was warm and I came to a stop or just in a lower rpm range it would stumble and misfire (and throw a CEL). Usually it throws misfire codes and timing codes. I could unplug the solenoid and drive the car around just fine (with only the code for the sensor not being plugged in). Anyway, it was like 90 bucks to my door for the part.

Just a thought.

2haloz

Well my transmission theory held up. It's the torque converter lock up solenoid. It doesn't want to let go when it comes to a fast stop. And it's not going to be as simple as replacing the TC.

They said depending on how bad the actual transmission is they could possibly just do the TC, but most likely its going to need another tranny.

I could get a used one, but by the time I pay for that with labor etc, I may as well swap. I guess 2jzgte here I come. I'll just have to feather around town until I can afford it.

marshun

all the solenoids are relatively easy to change. i dont know which one is the "lock up solenoid" though. i guess i got some reading to do cause my car recently started not downshifting to first gear smoothly. a little hesitation

http://s3.amazonaws.com/2cp-images/q...8980/large.jpg

2haloz

But what I don't understand is that if this is electrical it should set off a code.

Thus leading me to believe this is mechanical. I might try pulling the pan cleaning it out, seeing what's in there... Flush it a couple times with new ATF and see if that gets things moving.

This was suggested by another member. I hope he's right. I can get a used tranny for 3 or 4 hundred and find somebody to pop it in or do it myself at worst. Aren't these transmissions supposed to be buller proof?