ST185 intermittent starting problem

PDoane

New member
This problem has occurred both before and after a Gen 4 3SGTE swap.

Lots of power, all the dash lights come on, relays clicks when ignition switch is turned, but no turnover. With key turned to start, pressing-and-releasing the clutch pedal also clicks the relay, but no turnover.

Sometimes pressing-and-releasing the clutch pedal gets it to start, sometimes it doesn't. I have thick rubber floor mats and I pull them out when I'm having this trouble to make sure the clutch switch is being hit.

Push starting the car works and sometimes the problem is gone after that and sometimes it isn't.

Since the relays are clicking I don't think that's it, but it could be. Could the starter have a dead spot?
 

celi703

Member
Check your grounds. I put a new motor in my alltrac and had the same problem. Replaced every ignition component and still same issue. Turned out to be a bad ground on the transmission and body. Now it turns on everytime no problem.
 

underscore

Well-known member
Definitely check your grounds, the easy way to check is to take jumper cables and run one from the block near the starter to the negative terminal.
 

quieter

Member
if you have the same problem after changing/adding grounds i would replace that starter. i had the same problem, very common with our cars unfortunately.
 

aus jd 2703

New member
depending what loom you are using you may need to perform the starter mod.
pretty much you use the old starter signal to trigger a 30amp bosch style relay.
due to old age the wires resistance increases until its to much and the voltage isnt enough to engage the starter solenoid.
bosch relays will trip at this lower voltage and then nice new wires take 12v straight to the solenoid.

its a work around but unless you want to run all new starter wires its the best solution.
 

mx6er2587

New member
^^^This^^^^

Toyota undersized the wire a bit and as the car ages and the harness builds up some corrosion you don't get a strong enough signal through to kick the starter solenoid.
 

PDoane

New member
Further data (that confuses me even more).

The only consistent time it does this, is after driving through a strong rain. When I try to start it after first stopping after a rain drive, it starts fine. Apparently when it cools off after the rain drive, then it won't start. This kind of led me to go with the bad/flaky ground theory offered above. I did try the "jumper cables for ground" idea, but it had no affect.

The last couple of times it did this (one with rain drive, one w/o), a failed bump start jogged something so that the ignition switch worked again????
 
I fought the same issue on my st185 for almost a year. I regularly had to pop the hood, unplug the signal wire from the starter and jump it straight from the battery with a large 8 gauge wire. What I found out was that after a previous starter rebuild and a possible over tightening of the 12v main to the starter, the contact inside was no longer aligned nicely for contact.

If you can regularly jump a good 12v source to the starter signal wire and you get it turn over, I recommend having the starter rebuilt and make sure you do not over tighten the main 12v wire for the starter.
 

alltracman78

Active member
You need to figure out if the starter is clicking or not. If the starter is clicking you need to focus on it and the wiring for it [power/ground]. If it's not clicking you need to focus on the wiring for the starter solenoid.
 
Top