Toyota 4AGE woes...

pclancy

I've got a 1995 Toyota Levin 4AGE Blacktop 20V engine.

For ages its had a weird electrical or fuel problem, I cannot work out which.

Symptoms:
Accelerating under normal or high power somewhere between 1500-3000rpm the car stutters and hesitates and "coughs" for a while then suddenly gets amazing power, drops a gear and drives away fast. Sometimes you put your foot down and the corresponding increase in RPM is very poor. Usually only when below 4000rpm or more. The cars got great power but often at low revs, especially when cold, its got terrible stutter and power problems below 4000rpm. WTF?

When idling at the traffic lights, auto gearbox in D, the car sometimes will stall. Rpm drops from 800 down to 700 600 500 then stalls. I've never known an auto to do that before. Unless its revved up or driving it will stall itself.

Troubleshooting so far:

Found:
1 plug on distributor was totally burnt out and not working, lead replaced also.

Replaced:
Oil, Transmission Flushed, Spark Plugs, HT Leads, Fuel filter, Distributor Cap, Battery.

Checked hoses, Checked Oxygen Sensor, Everything I can think off and have been to several garages. Alternator appears okay.

Shorted diagnostic breaker and dashboard light shows no error codes.

I can't for the life of me decide if this is a fuel or electrical problem.

Any old Toyota engine experts out there?

Next step will probably just have to be auto electricians but i'd love to solve this

Anan1

Have you checked the fuel pump/lines?

R.O.R

Does it have a kickdown switch under the accelerator?

Sounds similar to what used to happen to my Dad's Carlton years ago.

Took 3 trips back to the dealer before they discovered the kick down button was getting stuck.

pclancy

A garage did so about a year back but I will check again.

pclancy

R.O.R wrote: »

Does it have a kickdown switch under the accelerator?

Sounds similar to what used to happen to my Dad's Carlton years ago.

Took 3 trips back to the dealer before they discovered the kick down button was getting stuck.

Its not at the point of harsh down pressure on the pedal that a kickdown would function that the problem occours, its low rpm/low pedal pressure when its dying, like when just idling or taking off.

MB1380

Have you checked the air flow meter? something similar happened to me and i gave that a quick clean with carb cleaner and solved it. Happened me with a golf aswell which had no air flow meter and i sprayed carb cleaner into the intake just before the butterfly valve while it was running and gave it a few revs, seemed to clear it out!

R.O.R

pclancy wrote: »

Its not at the point of harsh down pressure on the pedal that a kickdown would function that the problem occours, its low rpm/low pedal pressure when its dying, like when just idling or taking off.

I have absolutley no idea why the kickdown being stuck was causing the issue, but I do remember it stalling at lights and generally being very sluggish under acceleration.

Might be worth checking as it's possibly the easiest fix if a bit of WD40 would stop it.

pclancy

Its got a map sensor not afm, i think i checked it before but worth look again..

PADRAIC.M

hi, this is quite a common problem with this engine actually and has 2 possibilities, if its the older model with the big air flow meter between the airbox and manifold- they gave trouble them, but the main cause of this problem was the crankshaft position sensor, this should solve all your woes ;-)

pclancy

Mate said its got a map sensor not an air flow meter would that be right?