4afe Intermittent Starting Problems

[click99m]

I have a 4afe in a ae111 as a daily.
When i turn the key to start it i get no noise from the motor, a hum can be heard at the back of the car which i can only presume is the fuel pump.
Crash starting the car works. The battery is fine (jumper leads from a running car has same result) , alternator works once running (multi meter reading).
The wires on the starter motor feel firm.
Rocking the car in gear and then trying to start has the same result.
Alarm + Demobiliser is fine and well.
The catch is that it starts fine and normal half the time.
Has anyone heard of this happening before?

[Kiwi-Corolla]

Have you done a quick diagnostics check to see if there are any fault codes?

Look in the engine bay and you'll see a small black box next to the left hand side strut tower that says 'Diagnosis' on it. Get a paper-clip or a small piece of wire and put one end into the port labelled TE1 and the other end into the port labelled E1 (the labels are found on the underside of the diagnosis box cover, much like a fuse-box).

Turn the key to the 'ON' position, but don't start the engine. If your connections are correct then the check engine light on your speedo will start flashing. Keep note of how many times it flashes as this is the code it is giving you. For example, if the code was 35 it would flash 3-times, have a short pause, then flash 5 more times, then have a long pause. If it repeats the same code after the long pause then that means it's the only fault detected, but if it flashes for a different period of time then that means there is more than one fault. However, if it flashes continuously then it means there are no fault codes detected. Take note of any codes it's giving you and post back here.

[sergei]

Brushes are gone on starter motor.

[Stu-]

Or the trigger wire has dropped off (/been taken off by comedian work mates)

[Grrrrrrr!]

Sticky starter solenoid/brushes or starter signal not getting to starter motor. Not sure how accessible 4afe starter motor is, but if you can see it/poke it with a broom handle then get a mate to sit in car and hold the key on start when its not starting, and give the starter motor a moderate tap with the end of a wooden broom handle. If it starts then remove starter and strip, clean/rebuild. (or replace if thats easier/cheaper). Make sure its not in gear, dont want you getting squished.

[click99m]

Got a test light on the ignition tab of the starter motor and it has power when the key is turned so starter motor it is.
Now to try and get the friendly little unit out.

My first time trying to find any error codes and it flashed constantly (well over a min) so glad thats my only issue

[92mr2paddy]

had this is my supra awhile back, nothing,, then sometimes would start perfect, i took starter out and the copper contacts where so worn they hardly made contact, replaced them and it started everytime like a new car.

[allencr]

When i turn the key to start it i get no noise from the motor,

No loud noise, a heavy metallic thunk coming from the back & bottom of the engine?
OK, then the starter's solenoid isn't even working and you know for sure that any problem with the starter motor itself, like brushes or copper contacts, can't possibly be diagnosed right now.

Test light to check if the ign key is putting power to that small wire going to the3 starter solenoid.
Jump the starter with 12V directly from the battery to the small solenoid terminal to help out a weak but still saveable solenoid.

[Crucible]

Its good practice to do voltage drop tests (loaded circuit) and double check batery terminals are tight, just to make sure before pulling starter.

[sergei]

When i turn the key to start it i get no noise from the motor,

No loud noise, a heavy metallic thunk coming from the back & bottom of the engine?
OK, then the starter's solenoid isn't even working and you know for sure that any problem with the starter motor itself, like brushes or copper contacts, can't possibly be diagnosed right now.

Test light to check if the ign key is putting power to that small wire going to the3 starter solenoid.
Jump the starter with 12V directly from the battery to the small solenoid terminal to help out a weak but still saveable solenoid.

Due to how the solenoid is wired the worn brushes will make it not engage at all.