Hi! I have an HDJ81V with an 1hd-t engine newly serviced for maintenance and my fuel mileage ratio is very high, I get 3-4kms to a liter of diesel fuel now. I would like to know if there is an adjustment screw at the injection pump that I can adjust without harming the engine idling speed? I tried adjusting one there but the idling went down, I guess I adjusted the wrong screw. Pix would greatly be appreciated. Thanks.
1hd-t Fuel pump adjustment
- Thread starter cyberfarmer
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Tapage
Club 4X4 Panamá
Yes .. there is another fresh thread here where I place some pics and ideas ..
- Thread starter
- #3
Thanks for replying sir! Sorry to ask but where do I find the thread and pix again? Thanks again.
Tapage
Club 4X4 Panamá
sandcruiser
....back in the saddle again....
3-4 km per liter?
Sounds like you may have other problems as well... that is really, really low
Do you have a lot of black smoke? That is a good sign of overfueling.
Before you adjust fuel, it is a good idea to install an EGT guage.
Sounds like you may have other problems as well... that is really, really low
Do you have a lot of black smoke? That is a good sign of overfueling.
Before you adjust fuel, it is a good idea to install an EGT guage.
- Thread starter
- #6
yes there is extensive black smoke when accelerating
Did the servicing include any work on the fuel system apart from fuel filter?
Injectors need to be done every 100000 klms or so and can be the cause of black xmoke.
Yeah, that was probably the idle RPM screw that you adjusted... 3-4kpl (30L/100km??) is REALLY bad though (but maybe understandable if you have a lift, massive tires (37's??), a lot of extra weight, and clogged injectors (although I still don't think you'd be breaking 5kpl in that case))... I'm getting 7kpl mixed driving and I've got a 6" lift (approx.), 35" wheels (315/75R16), stock gearing, a bullbar, and a winch (a bit of extra weight)...
Definitely get the injectors serviced if you didn't get that done in your "service," since clogged injectors can apparently have a negative impact on fuel consumption (I'm planning on having mine serviced next week but I doubt it'll help much)...
I don't mean to hijack this thread but: an acquaintance of mine told me that you can adjust (turn down) the fuel intake in diesels but that, if you do, you have to re-adjust the timing. Does anyone know if this is true?? Also, sandcruiser, I was wondering if an EGT gauge is all you have to install before adjusting the fuel intake?? My Cruiser has quite a bit of power and I was hoping to decrease the intake 10 or 20% to help lower my fuel costs (it is my daily driver). I was planning on just taking it to a specialty shop in my area that deals with this kind of stuff but I read that "if the turbo is not set up correctly, it will push in more air than the engine can handle. This usually leads to a 'lean' condition - too much air, not enough fuel - which directly results in excessively high combustion temperatures and severe engine damage. For this reason, a boost gauge [is good to install before any modifications]." Because the 1HD-T is turbocharged I'm guessing that simply "turning down the fuel screw" can cause problems (e.g. a lean condition) and so it's a good idea to install an EGT, but I was just wondering if that's all you need to install.
Thanks for any input,
Rob
Definitely get the injectors serviced if you didn't get that done in your "service," since clogged injectors can apparently have a negative impact on fuel consumption (I'm planning on having mine serviced next week but I doubt it'll help much)...
I don't mean to hijack this thread but: an acquaintance of mine told me that you can adjust (turn down) the fuel intake in diesels but that, if you do, you have to re-adjust the timing. Does anyone know if this is true?? Also, sandcruiser, I was wondering if an EGT gauge is all you have to install before adjusting the fuel intake?? My Cruiser has quite a bit of power and I was hoping to decrease the intake 10 or 20% to help lower my fuel costs (it is my daily driver). I was planning on just taking it to a specialty shop in my area that deals with this kind of stuff but I read that "if the turbo is not set up correctly, it will push in more air than the engine can handle. This usually leads to a 'lean' condition - too much air, not enough fuel - which directly results in excessively high combustion temperatures and severe engine damage. For this reason, a boost gauge [is good to install before any modifications]." Because the 1HD-T is turbocharged I'm guessing that simply "turning down the fuel screw" can cause problems (e.g. a lean condition) and so it's a good idea to install an EGT, but I was just wondering if that's all you need to install.
Thanks for any input,
Rob
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sandcruiser
....back in the saddle again....
the pyrometer (EGT guage) is a great tool, especially if you are adjusting your fuel level. I don't know about the lean condition running that you describe, normally more boost tends to lower EGTs, not raise them (to a point). Maybe someone wiser can add their 2 cents.
Yeah, I wasn't sure why more pressure (boost?) would increase EGT but according to the website that I found that on it does... I'm not sure if decreasing the fuel intake by 10-20% would cause that much of a change in EGT (from "stock" values), since this engine is designed to be turbocharged, but I'd rather be "safe than sorry" (I think that the lean condition described might be a bigger concern if you are adding a turbocharger to an engine that was not designed to be turbocharged but I figure that the concept is the same: more (too much?) air and less (not enough?) fuel... I'm sure that the stock a/f ratio has been carefully researched and so I'll definitely install an EGT before I start messing around with the injection(/fuel?) pump, but any insight, from someone wiser, about what kind of results to expect as a result of turning down the fuel intake would be much appreciated.
Thanks in advance,
Rob
Thanks in advance,
Rob
- Thread starter
- #11
Hi Again! My injectors have been serviced also and theyre in good condition. I brought it again to the shop mechanic and they adjusted the screw behind the inj pump. Im getting good mileage now but the idling is off! its about 650 and whenever I engage reverse on incline the engine stalls. Inj pump timing is normal. Would i still be able to return idling at normal even if I dont touch the screw behind the inj pump to maintain the fuel consumption? Thanks guys.
Hey man, you should be able to adjust the idle RPM and maintain the fuel consumption. Apparently excessive fuel consumption only becomes a problem if the idle speed is set too high (which is spec'd. to be 600-700 rpm for a 1HD-T with a manual transmission and 750 - 850 rpm for one with an auto.)... Thus, you should easily be able to increase your idle speed 150 rpm without increasing the amount of fuel your truck consumes. Try it out and see what happens (it's only a matter of turning a screw, and you already know which screw it is, so get it up between 750 and 850 and drive the thing around for a while). I'm not sure how accurate the in-dash tachometers are on these things, so it might be a good idea to attach a tach. to your engine before adjusting the RPM but, since I'm not an expert in this area, the in-dash tach might be fine.
If you need any help with troubleshooting in the future you can try consulting the 1PZ, 1HZ, 1HD-T engine repair manual (an digital copy can be found in a sticky at the top of this forum). For help with excessive exhaust smoke (you didn't mention if you are still blowing extensive black smoke when acclerating) or fuel consumption see page 23 (EM-11) and 24 (EM-12), respectively.
Good luck getting your truck to do what you want it to do,
Rob
If you need any help with troubleshooting in the future you can try consulting the 1PZ, 1HZ, 1HD-T engine repair manual (an digital copy can be found in a sticky at the top of this forum). For help with excessive exhaust smoke (you didn't mention if you are still blowing extensive black smoke when acclerating) or fuel consumption see page 23 (EM-11) and 24 (EM-12), respectively.
Good luck getting your truck to do what you want it to do,
Rob
Tapage
Club 4X4 Panamá
Adding more boost ( lowering the EGT numbers ) or making the AFR lean like 20:1 does not make any problem .. you will found diesels in some situations running as lean as 50:1 or more ..
Thanks man, any idea what the "stock" AFR numbers are (I'm guessing < 20:1)??
Tapage
Club 4X4 Panamá
actually 14.7:1 should be the number .. but I never run an AFR meter in my turbo diesel cruisers to know ..
Right on, thanks...
Does anyone know the answer to if you adjust the fuel intake in diesels you have to re-adjust the timing? Maybe from someone who has over/underfuelled their rig?
Cheers,
Rob
Does anyone know the answer to if you adjust the fuel intake in diesels you have to re-adjust the timing? Maybe from someone who has over/underfuelled their rig?
Cheers,
Rob
Tapage
Club 4X4 Panamá
you can adjust the fuel alone .. there is no big deal on that if you have a properly instaled and function pyrometer .. and know exactly what are you doing ..
Sweet, thanks man, I'll fit a pyro onto this thing before I start fiddling around with the fuel screw in that case...
