Old Toyota 4 will not start reliably

My 89 4Runner does not start reliably. It has a 6cyl and auto, and I’ve replaced the starter, battery, battery cables to improve starting reliability. When the engine compartment gets hot it wont start and when I’ve started it several times over in an hour (like when running errands), all electrical works but the starter does not have enough juice to turn the engine over. It just clicks. So I have 2-3 alternatives. I can wait until cools and/or naturally recharges or I battery jump it from another car. Very Frustrated

Double post.

Two things come to mind.

The first is the possibility of a defective starter relay that’s become heat sensitive. In that vehicle I believe there’s one in the relay box on the top of the wheel well, under the hood.

The second is a starter motor being cooked due to an exhaust leak or missing heat shield.

Clean up the engine to firewall ground wire at the firewall end. Scrape the paint off the firewall too.

Did the new parts make any change, for better or for worse?

These starters’ most common failure is the 2 copper contacts inside the solenoid, which is built into the side of the starter casting. The contacts wear down, the plunger gets a little gunked up with dust, etc. and the net result is the plunger slides and bottoms out (that gives a muffled click sound) without moving quite far enough to firmly touch both contacts firmly. So the circuit is not completed and the starter motor does not turn. I repaired this on an old Toyota truck and also a Plymouth minivan - both use the same starter brand.

That it is heat related makes the rest of the starter motor suspect, too, but I don’t know much about that.

Several things

  1. Apologies for the double post.
  2. These are all great suggestions. I will check the ground wire attachment and the solenoid contacts.
  3. I’ve always thought that its becoming heat soaked. The 6cyl and auto leave little room between the exhaust manifold and the starter. But the new starter has a small heat sheild so I’m now looking for other possible causes. BTW, this is the second starter I’ve installed in 4 years to solve the problem. But I think the solenoid may be the problem and I recently learned that I can add a separate Ford solenoid up higher in the engine compartment to keep it in “cooler” air.

I thought “starter solenoid contacts” at first too, but if this vehicle is like my Toyota trucks the solenoid is built in as part of the starter assembly rather than mounted onto the side. When he changed the starter he would have had to change the solenoid at the same time.

I have a 90 4runner and I am experiencing the same exact problem right now. My husband has replaced the starter twice in three months and replaced cables, battery and battery cables. After this last starter, the runner worked for one week, then, PFFt, it started clicking again. We were advised to have the ignition system checked for “security issues with the theft protection system”. We are taking it to a mechanic friend later this week, if we find out anything I will be sure to let you know.

Usually heat soak means that the starter cranks slowly. Too bad the ground wire trick didn’t work, a 74 to 79 Corolla was the car that this trick worked on. I’m sorry to see that the newer ones aren’t so easy to figure out.

Is it charging OK? My experience with aftermarket alternators is not good on Toyota?s. If it is not charging at 14.5 volts and putting out the amps it should, replace the alternator with a new one from the dealer. This test is to be done with a voltmeter and an amp meter with a shunt.