LX470 misfires, died

DAA

Well-Known Member
Can you out a camera into the piston to see how bad it is without pulling the head? That looks bad...

Possibly, maybe a cheap camera bore scope or something. I tried with my bore scope for rifle barrels, but it has a 90* mirror on it so I couldn't see the piston. Could see there isn't much left of the threads in the head. Probed with a long screwdriver, didn't find an obvious hole in the piston. I'm not real optimistic about what it looks like in there though.

- DAA
 

DAA

Well-Known Member
So I went and got a cheap digital inspection camera from Harbor Fright. Can actually see the piston very well with it. And the piston looks perfect.

The spark plug threads are in bad shape, but there is still some thread there. I'm thinking about trying to helicoil the threads without taking it apart. If that works, put a new plug and a new coil pack in and see what happens.

- DAA
 

Greg

Make RME Rockcrawling Again!
Admin
So I went and got a cheap digital inspection camera from Harbor Fright. Can actually see the piston very well with it. And the piston looks perfect.

The spark plug threads are in bad shape, but there is still some thread there. I'm thinking about trying to helicoil the threads without taking it apart. If that works, put a new plug and a new coil pack in and see what happens.

- DAA

I think that's the cheapest/best option right now, done right it'll last the life of the vehicle.
 

Agility Customs

Well-Known Member
Vendor
I bought a civic back in the day that had some missing threads in the head where the plug goes and I literally JB welded the threads and tightened up as tight as I dared to and proceeded to put another 100k miles on that car, Mind you this was a 600 dollar car when I bought it. Just a funny story I dont commend that type of behavior.. :D
 

Kiel

Formerly WJ ZUK
it's pretty common stuff for the coil pack to go out at a certain mileage, I've done 5 outta 8 on our 4.7 over 7 years. Carry a spare. You can get the denso ones on Amazon for like 50 bucks
 
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4x4_Welder

Well-Known Member
Location
Twin Falls, ID
There are some great spark plug thread repair kits on the market now for under $100. The helicoil style is easier to use, can be done as a first step, and if it fails later can be replaced with the shell style. Just make sure you very carefully follow the directions, or you can trash the head.
 

Kiel

Formerly WJ ZUK
Pretty sure I recall the toyotas need to see that electrically the coils exist, so if one was that bad, no start, just crank.
 
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DAA

Well-Known Member
Did you ever try to turn it over by hand yet?

Yes, it turns over by hand.

Ordered a coil pack and a helicoil kit, so will hopefully have that part done in a few days. I'm out of ideas on the no crank though. Not that I had that many ideas to begin with. Something fried, I'd guess, but troubleshooting just what, I'm over my head I think.

- DAA
 

cruiseroutfit

Cruizah!
Moderator
Vendor
Location
Sandy, Ut
Yikes, that is a wild one. I can't say I've heard of the no crank related to the coil packs but then again I don't know that I've seen one that toasted either. I'm with Bryson, it may be causing a full on short.
 
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DAA

Well-Known Member
Not a real load test. I just left the lights on for a minute to knock the surface charge off. 12.55v. Pretty marginal I'd say. Putting a jumper on it doesn't do anything as far as cranking.

- DAA
 

DAA

Well-Known Member
It lives!

Thread insert in the head for the spark plug, new plug, new coil, new coil connector/pigtail soldered on. Cranked right over. Started right up. Seems to be running fine? No test drive yet. Going to give the thread sealer on the helicoil another 12 hours to cure first.

Fingers crossed. Knocking on my wooden head, all that. SRA might be back terrorizing the streets tomorrow though :D.

- DAA
 
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