Hello,
I got a 1989 Cressida with a 22r carburated engine. Yes, they came in Toyota Cressidas in my neck of woods. and i have had this car for more than 23 years and it has really served me well.
The odometer broke a long time ago but if i had to guess it probably has over 400k miles. I try to stay on top of maintenance.
MY issue is this. The car does not "LIKE" to go over 50mph. This doesnt mean that it cant. It will keep going if i floor it and that too, smoothly without misfires or clutch slippage , but right around 50mph mark, i feel the engine starts screaming, like rpms are high and it is under severe load. However, i dont think it is the clutch, as in the city driving even when i punch it, it accelerates normally and smoothly. Idles perfect , starts up perfect, and has plenty of power in the city and is very responsive.

In my mind, it seems either transmission or maybe worn piston rings, but i don't know if these would cause this condition. Please discuss these 2 in detail for me w.r.t. my issue..

• I have rebuilt the carburetor recently. ( maybe i messed up something here but the vaccum secondary seems to be working)
• changed fuel filter, air filter, spark plugs.
• timing is fine, maybe slightly advanced but that would not cause this.
• tires are fine and aligned.
• there is no cat on the car.
• no vaccum leaks .

also, something i have noticed recently is that the car has become a gas guzzler. whereas before it has great gas mileage.

Hope, someone can help me accurately diagnose this issue.
Will be highly appreciated.

 

My first question. Did you rebuild the carb because of the problem? Did the problem start after anything you did? What do your plugs look like? What is your timing set at? Besides the cat missing is everything else correct? What transmission?

 

• Rebuilt the carb because it was leaking a little gas at the base, fixed it with the rebuild.
• NO, don't think the issue appeared suddenly after a change.Rather, i feel it happened gradually over a period of time.
• The plugs get black carbon deposits on them and more importantly oil on them though the valve cover cover gasket has been replaced. Also i know that the car burns a little oil. Maybe less than a quart in 2 months. it smokes at the back only when revved really high and the amount if smoke is not very bad.
• I do not have a timing light so couldn't give you an exact number. But the distributor is set more towards the clockwise(right) end of the adjustment. BUT, there is no pinging or starting issues.
• Transmission is w56. Shifting is smooth, no grinding . Could it still be related to the issue at hand.?

 

Sounds like the Trans is just fine. I would want to know why your plugs are getting black and fowled? My guess is something is off in the carb. I honestly dont know a lot about 4 stroke carbs but it seems fueling related with fowled plugs. How long does it take you plugs to go from new to black deposits on the electrode?
I dont see how valve cover could be a suspect for the plugs. The important parts are either in the head or covered by plug wires. If it's hemorrhages oil then maybe but thats like a quart a week amount of oil. I would try and rent/borrow a compression tester for a quick check. Most auto parts stores will rent you one and then refund your money when you return it. Also rent a timing light from them as well. Its always better to confirm everything is set properly before trying to "fix" things.

 

Thanks your your suggestion. I will test the compression and report back here in a couple of days. However,..

• Can worn piston rings lead to this condition where it starts screaming loudly (violently) over 50mph ?? I mean lot of car cars burn oil but they still drive normally, right? However please note here that it will actually keep on accelerating higher if i push it further but i avoid going higher so as to not overstress the motor since it feels like it is about to explode over 60mph. though 50 seems to be the sweet spot.
• Plugs get dark within a week so yes it maybe running a little rich and as mentioned before it consumes lot of fuel. Please tell me exactly what circuit/component of the carburetor would lead to my scenario.so i can look into that. ?

I know this car is old. I have another newer vehicle but this one has sentimental value since its been with me for so long and i want to keep it.

 

Ok, i am back with the compression results.
Cylinder#1: 160-165 psi
Cylinder#2: 165-170 psi
Cylinder#3: 160-162psi
Cylinder#4: 140-143psi

I see that #4 is low on compression. But before i dive into a rebuild, i want to eliminate the issue i am having if it is not related to this.
There is no shaking or misfire in the motor and ides smooth.
i would to like to request all the experts to please chime your opinion in here. Will be highly appreciated.
Thank You.

 

You said your valves are getting oily, this likely leaking valve seals. And explains some if your oil consumption

You don't have a timing light, get one and check the timing. A cheap one works just fine your not doing it or you any favors by holding onto that $20.

Once you have a good base timing, you need to look into your vacuum advance.

 

Number 4 is a bit low but that alone isn't your problem. After the timing is confirmed and the vacuum advance is confirmed correct then we can get to the carb. But lets verify everything is set correctly before we start ripping a carb apart.

 

Thanks for your suggestions. Been busy but will check these and post here what i find. Thanks.