1HDT starter issues (1 Viewer)

[franklin40]

first off a disclaimer i'm not good with vehicle electrical diagrams or terms but i am learning.

i have a 1hdt swapped into my fj62. for the last year the starter has been giving me issues and its been getting worse. it will start intermittently and when it does is firers right up so fuel isn't my issue if the starter turns over the truck starts right up. i can heart loud click at the starter but no turn over. it got to the point last week that i was push starting my truck more frequently than the starter worked. i took the starter in and had it rebuild by a reputable shop. they installed a new brush setand rebuild parts and machined the armature. i installed it and the truck fired right up. right on!! turned it off and started it again. perfect... until i tried starting it a third time. just a click and no start. a few more bumps and it started again but after turning it off im still having to bump it a bunch with the key to get it to start. any ideas what this could be, its a 12 v starter and a 12 volt system. batteries are good and like i said when it starts it starts strong. just intermittent.

thanks for advice on where to check next

 

[lynchmob]

Maybe check all your grounds in the system. The battery should be grounded to the frame and body, and there should be one or more ground straps between the engine and frame and body.

Its possible the ring gear teeth on the flywheel are damaged but it would have to be pretty bad to cause an issue.

 

[morganism]

on the gas models, this is caused by a bad ground on the coil and ignitor, so the advice about grounds is prob correct. do you have all the speeds on your heater blower? there is a big resistor there that can fail, and become a big draw too.

 

[Greg_B]

Grounds are a good start.

What voltage is making it to the trigger wire on the starter when you turn the key to the ignition position when the no start occurs?

Also, your cable from the battery to the starter contacts is good?

hth's
gb

 

[franklin40]

all my grounds seem good and they are newish (couple years old)cables. i jumped the ignition wiring straight from batter positive to post on the starter and it fires perfectly each time so it’s a amperage loss in my electrical through the ignition wiring. maybe just worn contacts somewhere or relays that aren’t allowing full power to get to the starter. i talked to the guys at the shop and they sold me a remote solenoid that’ll make sure there’s full power without it going through the ignition wiring harness. just straight from battery. hope that works. is how more modern starters are build now a days apparently. this will just be a retrofit on an old starter

 

[franklin40]

on the gas models, this is caused by a bad ground on the coil and ignitor, so the advice about grounds is prob correct. do you have all the speeds on your heater blower? there is a big resistor there that can fail, and become a big draw too.

yeah all speeds work on my fan

 

[db3]

i talked to the guys at the shop and they sold me a remote solenoid that’ll make sure there’s full power without it going through the ignition wiring harness. just straight from battery. hope that works.

That will take care of your problem. I had to add the relay for my 1HZ conversion.

 

[franklin40]

done. it worked. good fix as far as i can tell. this is the wiring diagram they gave me. i drew 12v power right off the battery cable on the starter and ran it to the battery post on the solenoid and then ran another wire back to the ignition terminal. the ignition wire then triggers the solinoid to close the circuit. it doesn’t take much power to close the circuit so even though there’s not enough power to energize the starter there is enough to activate the remote solenoid which then brings full amperage to the ignition terminal. really quite simple in the end.

 

[mudgudgeon]

If it clicks a few times in succession, it's likely that the contacts inside the starter solenoid have eroded away and you're not getting enough current through the solenoid to keep it engaged.
Every time the contacts come together and break contact there's a bit of arcing which erodes the copper away.

I replaced contacts in one of mine with generic contacts from my local auto sparky for a few bucks

 

[franklin40]

contacts were replaced. it was only one heavy solenoid clunk that was happening too. ill drive it today and see how it goes but in my tests so far this has fixed it

 

[1HaytchZed]

Doesn't the 1HZ starter already have a solenoid on it? Confused.

 

[John in Utah]

Doesn't the 1HZ starter already have a solenoid on it? Confused.

Most starters do, yes. Beside switching power to the starter motor, the solenoid also acuates a plunger that is moving the pinion gear into contact with the flywheel ring gear. The problem is the ignition switch is handling the load from the battery to this solenoid. Adding a second solenoid (technically a relay) to this system is lessening the amperage through the ignition switch and ensures you’re getting consistent power to your starter.

FWIW an auxiliary relay solved my starter gremlins as well.

 

[franklin40]

Most starters do, yes. Beside switching power to the starter motor, the solenoid also acuates a plunger that is moving the pinion gear into contact with the flywheel ring gear. The problem is the ignition switch is handling the load from the battery to this solenoid. Adding a second solenoid (technically a relay) to this system is lessening the amperage through the ignition switch and ensures you’re getting consistent power to your starter.

FWIW an auxiliary relay solved my starter gremlins as well.

well explained.

 

[1HaytchZed]

Most starters do, yes. Beside switching power to the starter motor, the solenoid also acuates a plunger that is moving the pinion gear into contact with the flywheel ring gear. The problem is the ignition switch is handling the load from the battery to this solenoid. Adding a second solenoid (technically a relay) to this system is lessening the amperage through the ignition switch and ensures you’re getting consistent power to your starter.

FWIW an auxiliary relay solved my starter gremlins as well.

Sorry thick skull I have.
Ignition switch is exactly that, it is just a signal going to the starter solenoid to tell it to close the circuit and deliver full amperage. So how does adding another solenoid in the circuit help alleviate the issue?

 

[db3]

I measured the current draw to my 1HZ starter solenoid - 18 Amps. A stock ignition switch is not designed to handle that type of current. Using an auxiliary relay to provide that type of current directly from the battery is an inexpensive solution.

 

[1HaytchZed]

I didn't realize the ignition switch is the current source.

 

[franklin40]

i hadn’t either until i talked to the shop that rebuilt my starter. over time the contacts in the ignition get worn and don’t allow the full current through. it’s plenty enough to close a relay though

 

[mudgudgeon]

I see what you've done now. Didn't read thoroughly before.
Interesting solution. Looks like a beefy relay!

 

[franklin40]

it’s worked perfectly. not one missed start since i installed it

 

[Bisonthecruiser]

Franklin! What starter solenoid relay is that you ended up with?