Lexus 1UZ Starter Motor Problems

[JON1D]

One thing to check is the battery cables positive and earth connections also earth straps.

Your seeing good voltage at the starter but you need to ensure load current is being supplied.

With it failing cold and hot that's eliminated heat soak. Unfortunately when starter motor windings start to go bad you get intermittent and slow crack when hot.
I did a lot of checking and in the end it can down to a starter motor replacement on a different engine. With intermittent problems they can be frustrating.

[Ian C]

Tommy,

No don't think so, it only fails to start very intermittently and can be either when cold or after a run.

When the fault is evident pressing Start Button causes a 0.5 - 1 volt drop and a current drain of a few amps which indicates that the solenoid is pulling in (it can also be heard as a click) but the contacts don't close so no power is getting to the starter motor coils.

The starter motor is the original unit so is now over 30 years old, I did think of replacing it before I installed the engine but it never faltered when I bench tested it.  It is the only aspect of the engine that I don't love - clever packaging but a nightmare to change requiring the removal of intake ducting, throttle body, induction plenum, intake manifold, fuel rail & injectors before trying to access the M10 fixings - which are at the rear of the engine in the narrow gap between the block & firewall where the wiring loom also lives.

Happy days, take care.

Ian

[Tommy-boy]

Is this not a side effect of heat soak mate?

Would a mini hi-torque be of any use? Sorry i'm not at all familiar with the setup on your engine.

[Ian C]

Hi,

Have not been on the forum for some time and was wondering if any of the 1UZ fan club are still around?

I have been suffering from an intermittent starting problem lately - the ubiquitous "click" when the starter button is pressed, volts drops by 1 - 2 volts so assume the solenoid is pulling in but the contacts to switch the power through to the motor coils are not closing - or if they are there is a high resistance between contacts.

You will be aware of the difficulties in replacing the starter motor on an installed engine so I want to make sure the fix is reliable.  The options appear to be a second hand (pre loved!!?) starter motor from a variety of sources at circa £70 - £80, or to go for a NOS or remanufactured item at circa £300.  Buying a used starter motor risks more problems further down the line and I might be better just refurbishing the current motor?

Can anyone recommend a reliable source for good quality starter motors for the 1UZ engine. 

Still loving the engine - it has never missed a beat (once it is going) since I had it tuned.


Ian