Hi Guys, hoping someone has some information on initial timing of a 1HDT injector pump in degree of advance? Also if there is an ideal setting? The reason I ask is my engine pump combination is far from standard and while I have set the pump based on plunger stroke as per the standard spec there is still scope to improve. Currently on a timing light I have 6o of advance however the engine feels like it needs a little more initial timing. Can anyone share their experience with timing settings? Thanks
1HDT Injector pump timing (1 Viewer)
- Thread starter eddie01
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
yotahed
Diesel Head
What was the measurement of your plunger stroke? If you set it on the high side of the spec(1.58mm), it would most likely be the safest and probably the best setting. Too much advance and your combustion pressures spike, which is hard on stuff. Im pretty sure 8degrees is the max you can run on an HD-T, but it gets noisy and you burn quite a bit more fuel..and its hard on the motor.
Id set it to the spec, play around with your max fuel and boost if your looking for power. Remember to disable your cold start advance lever with a shim before measuring.
...via IH8MUD app
Id set it to the spec, play around with your max fuel and boost if your looking for power. Remember to disable your cold start advance lever with a shim before measuring.
...via IH8MUD app
Last edited:
Download FSM for free on here - sticky at top of main diesel forum page. Turn to pg EM-23. You will need the SST and a dial gauge. Some use a VW timing tool As yotahed said, set to upper end of spec. Or tune by ear. Loosen and tilt towards block to advance.
Can you please describe this a bit better? maybe with photos or drawing? I need to adjust my timing and want to do it right. I have a HDJ80, 1993 with 1HD-T and have the tools.
yotahed
Diesel Head
As said above, download the manual. Its in the Engine Mechanical section. Specified shim thickness for your cold start advance(ACSD) is there as well. You have to move the lever so your timing isnt advanced by the mechanism while setting it, which will upset the reading. The shim is just to hold it there whilst you mess around with pump.
...via IH8MUD app
...via IH8MUD app
- Thread starter
- #6
yotohed
Thanks for the reply, yes I always install these pumps with plunger stroke, but due to modifications on pump and engine wanted to compare with a timing light. You say 8 degree max?
It is only the initial response I am looking at improving a little and I think a bit more advance and a little more fuel before boost and we should be good. But before I adjust the fuel anymore wanted to double check my timing to start. Interesting your spec is 1.58mm on the high side? all my spec books are 1.35mm
Thanks for the reply, yes I always install these pumps with plunger stroke, but due to modifications on pump and engine wanted to compare with a timing light. You say 8 degree max?
It is only the initial response I am looking at improving a little and I think a bit more advance and a little more fuel before boost and we should be good. But before I adjust the fuel anymore wanted to double check my timing to start. Interesting your spec is 1.58mm on the high side? all my spec books are 1.35mm
yotahed
Diesel Head
Sorry bud. I was looking at the 1hd-ft manual.
In Europe it says 1.43mm. Rest of the world it says 1.58mm
But you are correct on 1.35mm for the 1hdt. I wonder why the FT has it .08-.23mm higher spec. You could always give those values a go and see how it runs. At least you have some min and max values to go off.
Cheers
...via IH8MUD app
In Europe it says 1.43mm. Rest of the world it says 1.58mm
But you are correct on 1.35mm for the 1hdt. I wonder why the FT has it .08-.23mm higher spec. You could always give those values a go and see how it runs. At least you have some min and max values to go off.
Cheers
...via IH8MUD app
- Thread starter
- #8
AHH that makes sense the FT is 24 valve but still mechanical pump compared to mine. Great engine, I like it a lot even over the FTE, no computer no long term issues in remote areas can fix most things yourself.
As for timing might push it out another degree see if that cleans up the initial response.
As for timing might push it out another degree see if that cleans up the initial response.
When I look up the injection pump timing specification there are two different values for earlier and later year motors. However, I think the earlier specification only applies to 1990-1993. 1994 to 1997 1HD-T in the 80 series would follow the later specification.
The RM617E FSM was written specifically for the 100/105 series. I spot checked a number of parts between a 1997 80 series and a 1998 100/105 series and they are all the same for the 1HD-T. Not the case when I spot check the 1990-1993 models.
This leads me to believe that the 1HD-T plunger specification for 1994-1997 is 1.18mm - 1.24mm
Earlier - FSM RM172E (Feb 1990)
Later - FSM RM617E (Jan 1998)
The RM617E FSM was written specifically for the 100/105 series. I spot checked a number of parts between a 1997 80 series and a 1998 100/105 series and they are all the same for the 1HD-T. Not the case when I spot check the 1990-1993 models.
This leads me to believe that the 1HD-T plunger specification for 1994-1997 is 1.18mm - 1.24mm
Earlier - FSM RM172E (Feb 1990)
Later - FSM RM617E (Jan 1998)
All 1HD-T motors are 12 valve.
mudgudgeon
Resident galah
1hd-t was superseded by 24valve 1hd-ft in '95.
There was different plunger spec for 1hd-t for europe vs rest of world too I believe
The 1hd-t stayed in production for some markets past ‘95. Mine is a 1997 build year. Also, I believe some 100/105 series got the 1hdt in 1998
mudgudgeon
Resident galah
Where did yours come from?
Costa Rica. Model year 1998 according to registration paperwork.
Stop wasting your time comparing plunger stroke numbers and just set it to where the engine runs the best for your desired performance needs and drivability requirements.
Don't forget about the timing advance pre-load either. So many people go chasing answers with the base timing when there solution was in fact with the timing advanced piston
Don't forget about the timing advance pre-load either. So many people go chasing answers with the base timing when there solution was in fact with the timing advanced piston
here you go... In this video he is timing a Toyota diesel (1HZ or 1HDT). You do know that a special tool is required, right?
