2H injector timing (1 Viewer)

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I have recently fitted a recon 2H engine to my old HJ47. I personally set the timing gears so am confident that they are correct but when I started the engine, black smoke with a smell of unburned diesel emerged. I made a "spill tube" and found that the injector timing was actually occurring at 11 deg BTDC (12HT timing) not at 18 deg BTDC (2H timing). So, that is 7 deg late!! That would explain the unburned diesel??? I have now removed the inj pump and intend to advance the gear by one tooth. Given that the gear has 64 teeth, that means 360/64 equals 5.6 deg. While the pump is out, I will loosen the back 2 nuts on the inj pump adjustment flange. These are very difficult to get to once installed. This will enable me to fine tune the timing once the pump is re-installed.
I think all this trouble has occurred because the new engine was a 12HT unit?? Not sure?? Are the timing gears different? ie 2H vs 12HT.
Any comments / advice on the above?
Thanks for your help.
Bill W.
 
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Further thoughts on my original post......Seeing that the pump shaft only rotates at half the speed of the crankshaft....I think I will have to advance the injection pump gear by 2 teeth in order to get the 5.6 deg advance.
Correct???
Bill W.
 

TLC Norway

woodwelder
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Sorry that i cannot help more, but isnt there any way you can tilt the pump enough to catch more of the degrees up?
I tuned this on my 2h, as per manual, after i had the pump off. then i just rotated the pump a micromill.
Seem to remember the length of the test tube was really importaint.

I dont think the timing gears are the same on 12ht vs 2h. can check my manual later today.

is your new engine a 12ht with a 2h IP?
 
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TLC & blis. Thank you gents for your reply. Sorry for the slow reply but I have had a lot of trouble accessing this forum since my original post. At first I thought it was my pc but had the same problem on others.
Ok, so I advanced the ip by one tooth. Very time consuming job!!!!! and checked the timing with a spill tube. Maybe it is now a few degrees advanced?? does a diesel get "pinging / knock" when too advanced? The engine still does not have good torque at low revs but starts much easier than the old one.
Have tried to rotate pump by loosening the 4 nuts on the adj. flange but cannot move it at all.
I'm not sure if the new block is a 12ht one. What is the difference? Timing gears different? So, yes, I could have a 2H pump on a 12ht block???? One major difference was the lube tube to the side of the ip. There is not a tapped hole in the side of the new block. I had to re-route the tube to the top of the oil filter housing. Correct????
How is the Northern summer TLC? Mid winter here in the South and getting a bit too cool! I will have to get my long trousers out if this continues. It is 6 deg C outside this morning!!!! Too cold!!!
Cheers.
Biii W.
 

AussieHJCruza

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It's unlikely that you have a 12H-T block unless the whole complete engine is a 12H-T. I believe the size of their bores are different.
Yes, a diesel can 'ping' if the timing is too far advanced. If you would like, I could send you the 2H service manual as a PDF. PM me your email address.
 

RufusTheDufus

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Seeing that the pump shaft only rotates at half the speed of the crankshaft....I think I will have to advance the injection pump gear by 2 teeth in order to get the 5.6 deg advance.
Correct???
Bill W.

If the injection pump rotates at half the rate of the crankshaft wouldn't you want to divide 720 degrees by 64 teeth to know how many degrees of crankshaft=one tooth? So one tooth is 11.25 degrees.
 

RufusTheDufus

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Have tried to rotate pump by loosening the 4 nuts on the adj. flange but cannot move it at all.

I ran into a similar problem on my H when setting the pump timing. I loosened all of the injector pipes and fuel filter hard lines on the pump and was able to rotate the pump fairly easily then.
 
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If the injection pump rotates at half the rate of the crankshaft wouldn't you want to divide 720 degrees by 64 teeth to know how many degrees of crankshaft=one tooth? So one tooth is 11.25 degrees.
Yes "Rufus", you are correct! Your mechanical reasoning was better than mine! By advancing the IP gear by one tooth has moved the timing from 7 deg early to about 4 deg late. Consequences???? Not too sure. Maybe I can hear some pinging, however the engine definitely lacks power under load.

"AussieH".....I do have the "Gregory's" manual but it really is not much help when it comes to the finer details of the injection system. Does the manual you have provide more detail? If so, I would like a copy but cannot see how to PM you. Please pardon my ignorance. Advice??

btw.....you should keep up with your homework!
Cheers.
Bill W.
 
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Mar 16, 2015
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Greetings,
Has anyone come to a conclusion as to why the injection timing is out, I have one exactly the same and am contemplating moving the pump a tooth, but would really like to know why it is out.
All is good, new injectors, pump calibrated and engine recently rebuilt, the timing marks are correct as per toyota manual.
Timing was retarded before strip down.

Regards
 
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Toyota engines have the type of engine molded into the block in 50 mm letters,usually around where the block meets head.
As 12HT are quite valuable these days, I doubt that the workshop would give you one as a 2H.
Bill , if you search on google there are sites with free downloads of the 2H/12HT manual. There were some links at the top of the 70 series forum, not sure if they are still working.
 

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