My daughter's 1986 Toyota Cressida... what's wrong with it...

Is it carbureted?

 

Clogged or bad catalytic converter? If they cats are bad it could send a signal to the ECU which would then retard timing, fuel etc.. Not sure if the 1986 cars had such sophistication though. lol It is probably using throttle body injection or some other type of fuel injection besides a carburetor.

If it only does it when cold you might want to see if there are major cracks in the exhaust system starting at the manifolds then back to the catalytic converter. A crack could mess up the observed air/fuel ratio and again cause weird computer issues. When warm the metals expand and reduce the size of the crack which may explain why it runs better when warm.

 

Bad fuel? Contaminated fuel?

I thought rotten eggs smell was not due to over fuelling as such, but also too much sulphur in the fuel? I thought over fuelling gave off a more metallic smell when it floods the cat.

But I am assuming you've already checked the obvious like spark plugs, spark leads, air filter as the symptoms sound like a misfire to me.

 

I'm going to assume the mechanics have checked the obvious like Grumpy mentioned as well as fuel pressure, MAF air sensor (breakage or cleaning), fuel pump, Throttle Position Sensor etc?

 

Toyota M engine - Wikipedia, the free encyclopedia

There is a good chance it has a 5M-GE engine, here are some specs for it.

 

In line fuel filter plugged- but I don't know why this would improve once warm?
Stuck float(carb)- but once again why would it improve?
Early FI might be carb like-in 1986 Toyota was switching to FI-expensive car like the Cressida probably had FI.
Sounds like a fuel problem-mechanical fuel pump- maybe some sort of diaphragm with a hole in it?
Why is it better once warm?
It needs a very rich mixture when cold-which it can't get because of whatever the problem is-when cbut once warm it vaporizes more fuel so it can get by on whatever "the problem" allows to flow.

Will it actually run at full power full acceleration once warm?Or will it just "run ok" at a steady 60 mph-maybe 25% of full power
Charlie
Check/replace in line filter-cheap and easy to replace
Our 1985 Corolla had a carb- 1986 truck also- but it was a low end stripper model-no ac, no bumper, no radio-had to pay extra for all 3.

 

My 1983 Camry had port fuel injection so a 3 year later Cressida surely does. The Camry FI was flawless the 230k miles we had the car except for needing a shot of Techron every 2 or 3 years.

A fuel pressure test during start-up and early running would determine if the engine is getting enough fuel pressure. Definitely a worthwhile test.

If the filter is old, it would be a good idea to replace it on general principles.

 

Bob,

Just let her drive the Corvette in your avatar until her car is troubleshot and repaired.

Out of curiosity how many miles does a 25 or so year old Cressida have on it and who's older the car or your daughter?

 

I'd buy it and 1JZ-GTE it.

 

Dear Sir,
Not sure if you've solved the problem with your daughter's 1986 Cressida or even if she still has it, but I had the exact same problem with my 1986 Cressida, even after a complete engine rebuild... Seems that the Airflow Meter ( AFM ) or Mass Airflow Meter was dirty. Took it to another mechanic and he figured it out... Car seems to run pretty good right now. Just thought I'd drop that off on you. They also replaced the TPS or Throttle Position Sensor, plus it has a new Oxygen sensor. Thought maybe the ECM ( Engine Control Module ) could have been bad, but no... It was the AFM / MAF sensor.

 

FOOTNOTE: We also replaced a kickdown cable about a year prior to the rebuild as well... That will also cause a loss of acceleration in a 1986 Cressida... Think it goes from the Tranny to the carburetor to throttle it.

 

wow.