RTH: torque spec for fuel injector rail (2 Viewers)

[cahill]

RTH: fuel injector rail bolt broke

I was installing my fuel injectors to FSM torque specification of 15 ftlbf. It felt like I was turning all 3 bolts quite a bit more than I would have expected so just incase I was overtightening I dropped the torque wrench back to 10ftlb. I kept going since I figured I'd be safe but before ever reaching that torque, I hear a loud crack while tightening down the middle of the 3 bolts. I could suddenly turn the bolt easily so I backed it out and it had a crack though the middle of it. I was lucky to get it out in one piece.

Is 15 ftlb really the right torque? I'm a little afraid to keep tightening up to that spec. I have to go get another bolt first, but hopefully someone will chime in by the time I'm back. Thanks.

 

[cahill]

Went to the local auto parts store and didn't have any luck finding the right bolt. Called the local stealership and they didn't have them instock. Called Cdan and he didn't either. He doesn't remember ever selling one before (that makes me feel like I must be doing something wrong). Called another stealership and they didn't have it either but could get it my the morning so I went with them since trying to overnight ship the part would have cost more than they were charging.. Both stealerships were charging 3 times what Cdan offered to sell it for. Thanks again Cdan for the great prices and service to us here on Mud.

Any thoughts how I broke the bolt? Do you think it was weakened by the engine heat?

 

[cahill]

So went back out to try and figure out where things went wrong. My torque wrench was set to 15 ftlbf. I have another smaller torque wrench that goes from 20 to 200 inlbf (inch lbs). 15 ftlbf is equal to 180 inlbf (12inch/ftx15ft = 180in). I set the smaller wrench to that torque and sure enough, it gives way so I guess my other torque wrench isn't working right.

What do you guys think I should do? I have no idea what the other two bolts are torqued to, as I was slowly torquing them all down at the same time with the "bad wrench". Should I unscrew them and make sure there isn't anything else broken? If I do unbolt the fuel rail and injectors again, will I need to get new fuel injector seals since they've been torqued down? Should I just leave them where they are at and install the new bolt when I get it?

 

[cahill]

On visual inspection and feeling the lower intake manifold and the 3 plastic spacers, nothing seems cracked; so I am leaning towards leaving the other two bolts the way they are and installing the new bolt when it arrives tomorrow. Anyone think this is a bad idea? Heres a picture just for fun of the newly cleaned fuel injectors from RC engineering.

 

[OGBeno]

You are overthinking this. Tighten them, attach the connectors, put the two intake manifold half gaskets in place, hook up your vacuum lines, install the ground at the back of the lower manifold, and put the upper sucker on.

Be done with it and move on.

 

[cahill]

I probably am overthinking this, but am venturing into new territory with this project and don't know what to expect. I just don't want any fuel leaks from overtorquing the seals.

 

[Buckru]

I made the exact same mistake when I did mine. My heart sank when Dan told me there wasn't one in the COUNTRY!! He pulled one of a spare engine and sent it to me. I still owe him a beer or two for that. Any way, no worries or problems on my rig so go get back to work.

Buck

 

[scottryana]

I would check your torque wrench 15 ft/lbs shouldn't break that bolt.

-- sorry missed the post when you found out your torque wrench was wrong.

 

[cahill]

I made the exact same mistake when I did mine. My heart sank when Dan told me there wasn't one in the COUNTRY!! He pulled one of a spare engine and sent it to me. I still owe him a beer or two for that. Any way, no worries or problems on my rig so go get back to work.

Buck

Sorry it happened to you to but glad I'm not the only one . I'm picking up the bolt this morning and hopefully getting everything else back together without any hiccups.

Thanks for the replies and reassurance that I can move along.

 

[duggy]

I think there are times when reading the how-tos on this forum you immerse yourself in the process of whatever you're repairing/replacing and worry yourself too much about each step. This forum provides great information but I feel it pushes me back a few steps only because I usually figure things out by looking at it and using logic instead of going through a step by step and I sometimes obsess myself over small details which aren't a big deal at all.

 

[86tuning]

I believe the main issue is that torque wrenches are only accurate in the upper 80% of their range. At the bottom 20% of the range they are known to be inaccurate.

So your inch-pound torque wrench would be more accurate, because you're using it in the upper half of it's range.

Also, having *slightly* overtorqued bolts won't hurt anything. Leave it be.

 

[cahill]

I believe the main issue is that torque wrenches are only accurate in the upper 80% of their range. At the bottom 20% of the range they are known to be inaccurate.

So your inch-pound torque wrench would be more accurate, because you're using it in the upper half of it's range.

Also, having *slightly* overtorqued bolts won't hurt anything. Leave it be.

It looks like I learned that info about torque wrenches the hard way. Now if that bolt would just get here I could keep on putting things back together. The dealership said they would have it at 7 this morning. When I went to pick it up they said it wasn't there and wouldn't be in until Monday at the earliest. I asked where it was getting shipped from so I could drive and get it myself if it wasn't too far from here. Apparently it is coming in from overseas and there isn't one listed in stock in any of the dealerships? I guess I'll have to wait.

 

[gwolf3]

does anyone know the size of these bolts?

seems like they are approx 5/8 - 18 ? but as i was trying that size it wasn'nt going in easy and i was worried about cracking something.

 

[Irish Reiver]

I have no idea what 5/8 - 18 means (I'm European and therefore metric by design). Nothing on your land cruiser is non-metric so no point in trying. At a guess you probably need an M8 - 1.25

 

[gwolf3]

I have no idea what 5/8 - 18 means (I'm European and therefore metric by design). Nothing on your land cruiser is non-metric so no point in trying. At a guess you probably need an M8 - 1.25

Thanks for the quick reply. I will try same tomorrow and post back the results. Unfortunately cannot find the stock bolts anywhere.

 

[Kernal]

Nothing on your land cruiser is non-metric

Just FWI: : the thread/design of the inspection port plug for the steering knuckle is BSPT (Britsh Standard Pipe Tapered) as are the threads for the oil pressure sending unit (different TPI however). The engine block drain plug/cock assembly appears also to be a tapered non-metric thread but I don't recall if anyone has ever figured out exactly which it is. And then there's the JIS (Japanese Industrial Standards) cross head screws which look like Phillips head, but technically are not. Probably a few other things I'm missing??

FWIW