1jz - Is this the starter motor??

[JustCallMeOrlando]

I have a 1JZ MZ20 and a 1JZ MA70 both have had this problem. I puled the starter out and put in some new copper contacts inside the starter and haven't had a problem since. I'd bet they are worn and dirty and your not getting a good contact.

This is usually the problem, and it's common to Mk4 Supras too. Contacts get ratty over time. The relay just usually gives it that extra kick it needed to overcome this, but it doesn't solve the real problem. That is achieved by replacing or cleaning the contacts.

[allencr]

ok, I think you have some sort of psychic ability. I just checked the terminals and gave them a wiggle. refitted switch and starts first go. You are the man! +rep

CLEANING and RE-FITING, so that they make good contact may give you better long term results, as wiggling just breaks through some of the corrosion/oxidation/buildup on neglected stuff that would be happiest with zero resistance.!! No 'Roo Doo at all in the electrical system connections; all bright metal to metal matching surfaces with a little electricity conducting & corrosion/oxidation preventing grease(dielectric??) smeared on it.
For more then a temporary fix it will have to be taken apart and ...