Starting issues, please help

[RockinRunner]

1990 4runner 3.0 auto 4x4

So I have this problem with my truck. 99% of the time it will start up the first time I drive it for the day, however after driving for a while like to work (15 miles on freeway) and park, it won't start, it just clicks.

The click comes from the open circuit relay (5 wires) behind the right speaker above the ecu. I probed the relay and when I turn the key the black/white wire shows like 6 volts going thru it, when's give that wire power with my probe, it starts right up.

Then it will start after that until I drive for a bit and repeat the process.

Has anyone else had this problem? It's not the starter, it has been replaced and so has my alternator and battery (because of previous issues) though my starter was replaced because of this problem and I was a fool to replace without checking wiring first.

Is it just the relay. Should replace or is the concern somewhere else?

Thanks for your time guys.

 

[KidVermicious]

It's a combination of tired ignition wiring and worn out relay. Replacing one will make the other fail faster, there's a better fix.

Toyota/Chrysler/Mitsubishi - Nippon Denso Starter Solenoid Repair

http://www.toyota-4runner.org/class...x-intermittent-no-crank-22re.html#post1117438

It's always good to search first.

 

[RockinRunner]

I saw the first link and searched before I posted, I just didn't see the same exact problems I had. So pretty much wire up my own starting system from the looks of it. Thanks bro

 

[RAD4Runner]

Tired "START" contacts of Ignition Switch.

1990 4runner 3.0 auto 4x4
The click comes from the open circuit relay (5 wires) behind the right speaker above the ecu.

First off, the circuit-opening-relay does not affect your cranking system (but the starter switch energizes it to initially power the fuel pump). That the truck starts after you mess with COR is pure coincidence.

Test starter relay it first. Starter relay is in the engine compartment, not under dash. See schematics here. First check if your starter relay clicks when you try to start. On the 22RE, if you do not have help use RAD4Runner's Special Service Tool

It's a combination of tired ignition wiring and worn out relay. Replacing one will make the other fail faster, there's a better fix.

Partially agree. I believe KidV meant "starting" wiring. Agree, IF RockinRunner's starting wiring is still same as 86-88 22RE's, starting contacts of ignition switch ARE surely tired, but chances are starter relay is still good (It's designed to handle high currents). On 1986-1988's Toyota made a boo-boo (like the missing cup holders- LOL!).
Good intention:
Toyota added a starter relay so starting contacts (ST1) of ignition switch will not have to pass high current necessary to energize starter solenoid coil (I actually measured 12Amps).
Poor implementation:
However, starter relay still gets power for its load from ST1 contact (DUH!)- further explained here

Clean fix of RE-wiring like I did will keep starter relay doing it's job, and will actually help extend the life of the ignition switch ST1 contacts. Same concept as "hotshot", but cleaner and stock.

Toyota/Chrysler/Mitsubishi - Nippon Denso Starter Solenoid Repair
http://www.toyota-4runner.org/class...x-intermittent-no-crank-22re.html#post1117438

Good fixes.

... wire up my own starting system...

Or simply and cleanly RE-Wire. My mod (really wiring the circuit the way Toyota meant it to be wired) relieves ignition switch of high current to energize starter solenoid, makes path of power from battery to starter solenoid significantly shorter, keeps stock parts and facilitates addition of kill-switch. Write-up here

 

[KidVermicious]

... snip a whole bunch of really awesome info...

 

[RockinRunner]

I don't understand how it's pure coincidence? The black/white wire on the open circuit relay gets power but not enough and when I apply battery power it starts up every time. If the starter relay is in the engine compartment, where? I can't find it...

 

[RAD4Runner]

I don't understand how it's pure coincidence? The black/white wire on the open circuit relay gets power but not enough and when I apply battery power it starts up every time.

Because as I explained, the Circuit Opening Relay Does not affect cranking system. How it works explained here.

22RE starting system explained hereSchematic is specific to 1986-1988 4Runners. Concept applies to others.

If the starter relay is in the engine compartment, where? I can't find it...

I have a first gen so not sure exactly where it is for 2nd gen. Like I said, check the schematic/Factory Service Manual on link. I believe it's in the fuse/relay block.

 

[RockinRunner]

You say it doesn't affect starting, however when it doesn't start, only 6volts go thru the blk/wht wire, when it does start 10 volts go thru it and when it doesn't start if I apply power it fires right up. I is indeed linked to the starter circuit somehow.and I have a 2nd gen 3.0L

There is no starter relay under the hood. It's under the dash on the drivers side and it works fine. The ignition switch is also working too, I traced the problem to the open circuit relay. I can't find any wiring diagrams that show me where those wires go so I'm a little stuck.

 

[RAD4Runner]

There is no starter relay under the hood. It's under the dash on the drivers side and it works fine. The ignition switch is also working too, I traced the problem to the open circuit relay. I can't find any wiring diagrams that show me where those wires go so I'm a little stuck.

And right now you are sure that you have found both the COR and the Starter relay and they are different relays, right?

IIRC, I found the location of the starter relay in the fuse/relay block under hood on some pdf FSM posted online but could not remember where it's posted.

You say it doesn't affect starting, however when it doesn't start, only 6volts go thru the blk/wht wire, when it does start 10 volts go thru it and when it doesn't start if I apply power it fires right up.

Makes sense. Problem is intermittent.
WHEN your start contacts on IGN switch make contact such that they have high resistance from pitting/corrosion, as soon as they try to supply the 12 amps to starter solenoid, you will get a lot of voltage drop across contacts, leaving you a low voltage at COR - same test point as coil of starter relay (again look at schematic). This time your starter relay may click but there's not enough juice to energize the starter solenoid.
WHEN start contacts make good contact (intermittent, right?) such that they have lower resistance, you get enough current through circuit to energize starter solenoid, less voltage drop across contacts, and you get more voltage at COR = voltage at starter relay.

WHEN you apply full 12V from battery to energize COR, you also apply full 12V from battery to starter relay, you bypass your tired/intermittent start contacts (my mod does exactly this), so you get full 12Amps running through your jumper wire to energize starter solenoid.

 

[Bmerr98]

Holy Thread Revival, Batman!

Replaced starter solenoid contacts. Rebuild kit came with a new plunger, so I replaced it, too. Should I have just cleaned the original up, or does it matter?

 

[Bmerr98]

Nvmd. I cleaned the old plunger up and put it back in, and I'm back in business. The old and new were close, but not quite the same. Seems a plunger will outlive several sets of contacts in most cases, so I believe this old 2nd Gen will go to its grave with this starter setup.

Just in time for off road season, baby!