Fuel Delivery Adjustments -12HT (1 Viewer)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

T

traveldud

Joined
Mar 1, 2013
Threads
62
Messages
561
The guy I bought the 12ht from increased fuel delivery to get a bit more power delivery. I have the white smoke on startup and then black smoke under load (acceleration/shifting gears). On highway speeds keeping the car going it's light, but mostly gone. Not burning oil. I've never been in another, but I'd say the engine seems strong. 175K miles on engine.

If it was a gasoline engine I'd think it was a bad case of blowby, but I'm hoping fuel adjustments may, at a minimum, reduce what may be unburnt fuel.

I'd like to know if someone has pictures to adjust fuel delivery or suggestions from simplest to most complicated methods of addressing the above.

From the manual, I believe it's pages FU-96, step 10 and EM-23 (big job) sound interesting, but I have little to no skills and don't want to start prodding without some experienced feedback. Thanks!
 
ForumRunner_20140225_100710.webp

This may be the screw your looking for, its on boost fuel screw. Its located just next to your six injector lines out of the pump. Turning this makes big differences. Out for more fuel under boost in for less fuel under boost. Be careful not to go nuts and forget where you started. There is also a screw at the back of the pump that controls off boost fuel but im not sure exactly where as iv never touched it. It sounds as if the off boost screw has been fiddled with if ur overfuelling at low/idle revs. Hope this helps

ForumRunner_20140225_100710.webp
 
Thanks for this. Do you know if this is something you adjust engine cold? idling? 1/4 increments for instance?
 
Do it warm. That way u can take it for a hard drive to see how it goes. That screw has a 10mm nut which works as a dust cover then another 10mm locking nut. Make sure you use two spanners to undo cover without lock nut coming loose or you will lose your baseline. The screw itself fits a 3mm allen key inside so u can adjust. Simply insert allen key and hold tight then undo lucking nut and adjust from there. Yes I think qtr turn increments are a good idea. Are u running standard boost? If you have a boost controller and guage and egt guage u should be able to tune the old girl fairly well yourself. Not saying itll turn into a race truck but u may be able to clean up that smoke a bit and get her shifting along. Let us know how u go
 
Thanks guys. I suppose I can let warm, go for a drive, come back, turn off, adjust leaner go for another drive. Slow, yes, but may be easier on the nerves. I hope to get to it sooner than later and will update correspondingly.
 
It really doesn't take long to adjust. Five minutes max if u know how to swing a spanner. Another option is to increase boost with a boost controller to put more air in to burn all that diesel. Does it smoke really bad on takeoff? Like car behind disappears or just a puff of black which is normal for these engines? They will anways shoot out smoke on start up cold or warm. Thats just the 12ht. Mine had done 500,000klm before I rebuilt and now brand new with 10,000km it does the same thing. Small puff idling away happily
 
I wouldn't say puff. I feel like I'm smoke screening the clowns that like to tailgate as I take off. So there's is a little satisfaction in that, but otherwise I feel like I'm just throwing the diesel out the window.

I don't have a spanner wrench, so I'd be using two 10mm wrenches if that works.
 
Hulsty said:
Turn up the boost instead!
Click to expand...

X2, both methods will reduce the smoke, but only one makes more power, and lowers EGT's.:grinpimp:
 
From some of the threads it does imply an injector issue. I only have the white smoke on startup, otherwise nice and black.

An injector rebuild I imagine is costly. I'd prefer to get another set, rebuild it and then put it in as the vehicle drives now and I have a fun trip planned for the spring. How complicated is it? What kind of $$ am I looking at?

What's the recommendation there? List a wanted thread? Do the injectors need to be off of another 12ht, or is this where the 2h could help out?

Thanks.
 
traveldud said:
From some of the threads it does imply an injector issue. I only have the white smoke on startup, otherwise nice and black.

An injector rebuild I imagine is costly. I'd prefer to get another set, rebuild it and then put it in as the vehicle drives now and I have a fun trip planned for the spring. How complicated is it? What kind of $$ am I looking at?

What's the recommendation there? List a wanted thread? Do the injectors need to be off of another 12ht, or is this where the 2h could help out?

Thanks.
Click to expand...

12ht is direct injected compared to 2h that is indirect, so yes... You need injectors from 12ht..
 
Thanks. It looks like these pump are nearly bullet proof from some other threads, but the injectors and nozzle can and could be addressed at one point

Also from another thread to round out my understanding "The fuel screw at the front controls the fuel under turbo boost, the one at the back controls the fuel before the turbo kicks in." The one in the back looks close to one inch/25 mm...that was a quick glance on dimension. Is that correct?

Not that I would do this, but to complete the picture, can someone educate me on boost adjustments or a link? How to adjust? Optimum boost at which temps, etc.
 
ForumRunner_20140226_060400.webp

This is what u want, boost controller on turbo wastegate actuator. Very easy job. Get a boost guage plumb it into crossover pipe youll find threads easily on this too. Wind up boost wind up fuel. Make sure u also have an exhaust gas temp guage. If your seriously going down this road a 3" exhaust is a must to get the hot gasses out. And without a muffler it'll sound awesome

ForumRunner_20140226_060400.webp
 
X2 on the manual boost control, you can pick them quite easily on fleabay for $40 for a good quality one.:cheers:

I'm currently in the process of inter cooling mine, but I might still buy one of these manual boost controllers, you never know when I might need to do a wheel stand down the main street:grinpimp:
 
You must log in or register to reply here.

Similar threads

DieselFJ
12HT Injector and Holder
Replies
5
Views
964
Eurasiaoverland
Eurasiaoverland
rideglobally
12ht real time help
Replies
11
Views
2K
ChiCruiser
ChiCruiser
Giles
12HT ticking turbo
Replies
11
Views
1K
cuteo100
cuteo100
WesCadwall
US Fuel Quality
Replies
12
Views
925
Tennessee Jed
Tennessee Jed

Users who are viewing this thread

Total: 2 (members: 0, guests: 2)

Share this page

Back
Top Bottom