[toycam88]

DOING my head in.

I have had a 92 sedan and now the 91 wagon do exactly the same thing! Yet my 88 sedan manual I have owned for over 20yrs has NEVER done it. Nor a 89 wagon also series one auto I had prior to these later models.
The problem is VERY specific to certain things.
1. ONLY at operating temp (middle of guage) 2. ONLY on deceleration (touch the gas or the brake it stops) 3. ONLY at Speed range 60km to 50kmph or 1000 rpm or less.
Its a surge, and its lunges the car back and forth. Both are autos. SO its something they added /changed in the series twos . 1990 - 1992
I will try to attach a video if allowed. We have changed only the coolant temp sensor and cleaned the throttle body. has anyone else had this and fixed it?
Two camrys both doing it a coincidence ? I think its more common..and hope someone has the answer. Thanks so much in advance.

 

[toycam88]

Hopefully the gif vid loaded.

 

[cd8000]

My 91 camry had no surging but at times it will lug 4th gear from 30mph and kept it there forever. No downshift occurred when I pushed the gas to wide open throttle. The transmission cable was adjusted properly by the mechanic.

5 speed manual = It will never ever have any issues with power. Unless it wore out.

 

[white90dx]

For those North American people reading - Toyota delivered the gen2 in '92 to other parts of the world.

As for your issue... In either '89 or '90 Toyota changed the programming of the ECU a bit that caused this issue. They all do it.

What you are feeling is an oscillation between 'idle' and 'decel' control in the ECU. The engine is coming back towards idle and is in fuel cutoff, then it gets below a certain RPM (1100 or so?), the idle control turns on (adds some fuel), which in turn increases the engine RPM above the idle RPM, then fuel is cut off again, etc. The hysteresis between these two modes is small enough in the later gen2 cars that the oscillation can occur.

When you put your foot on the brake, the car stays in 'idle' mode and the oscillation stops. If you put your foot on the gas, the engine RPM increases and it stays out of 'idle' mode.

If you turn off the overdrive, it probably won't do it... It is such an odd area of operation that you may have to just live with it.

-Charlie

 

[toycam88]

Thank you for that information Charlie.
I will definitely try to take it out of overdrive and retest it. As for living with it, its too severe jerking for that. :frown:
I also find it bizarre that it will only do it at operational temp, wonder if there is a way to keep the engine reaching that eg. running cooler but unsure if that would be optimum.
Has anyone been able to swap out a earlier ECU from the series 1 and had success? I have a "Donor" Ultima 1989 but not sure if it would be compatible by way of plugs etc.
Short of changing out every component its really sad that such a common issue has not been recalled or offered by Toyota to reset.
Did the Video / gif load at all guys? I cannot see it as an attachment.
Again thanks for the help/input.

 

[toycam88]

Also Like to mention that I have done a few diagnostic code readings and come up with Zero fault codes to date.
We also changed the coil pack as we know its common for the distributor and the oil seals leak as did this when I purchased it.

 

[71Corolla]

This can be caused by a bad or improperly adjusted TPS. Combine that with a transmission that would benefit from fresh fluid and you have a herky jerky driving experience.

 

[JimBowNut]

Video did not load mate.

 

[Temeku]

Don't see a video anywhere. And the way you worded it, it sounds like your car is just horny (lunging, surging, hunting).....

 

[toycam88]

Update.

LOL Temeku Then it would be a Pleasant experience :grin:
Ok We have done a service on this old girl , we replaced the plugs, oil, filters and removed a badly coked up throttle body which was cleaned. Distributor removed as its a given they leak from the inner seal and have cracked coil packs. Havent changed the tranny fluid but will thanks.


So under advisement I took her for a drive down some back roads where I could concentrate on the gauges (what the vid was showing) so here is what happened. Maybe the files too big I will try to reduce it , here's a still shot within the rev range lowest point between 60 and 50 on deceleration.


Overdrive OFF A/C OFF still surged but lesser speed and RPM 40kmph 500-700rpm
Overdrive OFF A/C ON surged at around 55kmph and 1000 Rpm
Overdrive ON A/C ON or OFF no difference original issue 60kmph/1000rpm
:frown:

 

[dem2757]

It's possible any egr buildup makes the programming much worse when it occurs as the a/f mixture is now not ideal


Sent from AutoGuide.com Free App

 

[white90dx]

Based on the description, it still sounds normal to me... (reason number 127 to drive a manual transmission car...)

If you really want to chase it down (and likely not get anywhere), you can try adjusting the TPS (make sure to follow the factory service procedures exactly) and check the EGR function, though I don't think either one is very likely to fix the problem.

-Charlie