So I'm getting back into my 1HZ-T build, having injectors inspected/serviced this week prior to rebuild, and given my desire to get this thing as close to a factory 1HZ-T as possible, and that turboed engines usually have slightly higher crack pressures, I figured I should try to obtain the 1HZ-T injector crack pressure specs and set them to that if they are actually higher.
But what are their specs? So i did a little research and figured I may as well share it here.
Here's the part numbers:
the 1993-96 HZB50L/R 1HZ-T injectors: 23600-
19035
my 2002 HZJ78L 1HZ injectors: 23600-
19075
interestingly the 23600-
19035 injectors in the 1HZ-T were also used in the following post-98 1HZ models according to the EPC, although three models is a very small number compared to other the injector part numbers I saw:
05/2005-07/2007 HZJ105R-GCMRSQ
05/2005-07/2007 HZJ105R-GNMNSQ
08/2012-to date HZJ79R-DKMRS (SOUTH AFRICA SPEC&HIGH ALTITUDE COMPENSATOR-WITH)
My current 23600-
19075 injectors were used in too many specific models to bother listing here but summarized as follows:
01/1998-07/2002, 05/2005-07/2007 HZJ105
07/1999-12/2014 HZB50
08/1999-to date HZJ71/76/78/79 L/R
So based on that alone you could assume that there would be little differences in crack pressure between the
19035 and
19075 if both were used on 1HZ in the same era as my current injectors, although the 1HZ crack pressures increased in 1998 by 7% as you can see from the repair manuals.
from the 1990 RM172E:
1HZ new 145-155 kg/cm2; 2,062 - 2,205 psi; 14,220 - 15,200 kP
1HZ used 135-155 kg/cm2; 1,920 - 2,205 psi; 13,239 - 15,200 kP
1HD-T No.2 132-138 kg/cm2; 1,877 - 1,963 psi; 12,945 - 13,533 kPa
1HD-T No.1 180-190 kg/cm2; 2,560 - 2,702 psi; 17,652 - 18,633 kPa
from the 1998 RM167E (100 series):
1HZ new M/T, A/T (white ring) 150-160 kg/cm2; 2,133 - 2,276 psi; 14,710 - 15,690 kP
1HZ new A/T (brown ring) 160-170 kg/cm2; 2,276 - 2,418 psi; 15,690 - 16,671 kP
1HZ used M/T, A/T (white ring) 145-155 kg/cm2; 2,062 - 2,205 psi; 14,220 - 15,220 kP
1HZ used A/T (brown ring) 155-165 kg/cm2; 2,205 - 2,347 psi; 15,220 - 16,181 kP
1HD-T No.2 135-145 kg/cm2; 1,920 - 2,062 psi; 13,239 - 14,220 kPa
1HD-T No.1 180-190 kg/cm2; 2,560 - 2,702 psi; 17,652 - 18,633 kPa
from the 1998 RM648E (70 series):
1HZ new 150-160 kg/cm2; 2,133 - 2,276 psi; 14,710 - 15,690 kP
1HZ used 145-155 kg/cm2; 2,062 - 2,205 psi; 14,220 - 15,220 kP
So not happy with that assumption alone, i kept looking for specs. I'm sure someone who works in a denso injector shop would have access to the proper database, but the only DENSO crack pressure specs table I found was repeated on dozens of chinese part seller sites (one of them linked below) and I looked up the date/model on the EPC for each part listed as either 1HZ, 1HZ-T or 1HD-T to see if the table was reliable or not. below they're ordered them by motor type and year of release.
http://www.starsdiesel.com/Toyota Injector-3768.htm
most of the list checked out OK, but some errors (in red) cast a little doubt.
Part No. kg/cm2 Motor EPC data
23600-69055; 145-155; TOYOTA 2C/1HZ/2C-L (01/1990- 07/1999 HZJ70/73/75/77/80/81)
23600-19045; 145-155; TOYOTA 1HZ
/2C (08/1992-06/2000 HZJ70/75/80)
23600-
19035; 145-155; TOYOTA 1HZ-T
/1HZ (01/1993-04/1996 HZB50,
not just 1HZ-T but HZJ105/HZJ79 listed above)
23600-19055; 150-160; TOYOTA 1HZ (01/1994-07/1999 HZJ70/73; 05/1995-07/2004 HZB40/50 - all Japanese models)
23600-
19075; 150-160; TOYOTA 1HZ (01/1999-to date HZJ71/76/78/79/105 HZB50)
23600-19105; 150-160; TOYOTA 1HZ (08/1999-07/2004 HZJ71/74/76/79)
23600-17010; 180-190; TOYOTA 1HD-T
/1HZ (01/1990-12/1994 HDB20/30/31; HDJ80/81)
23600-17030; 140-146; TOYOTA 1HD-T (08/1992-02/2001 HDJ80/81)
23600-17031; 180-190; TOYOTA 1HD-T (01/1993-04/1995 HDB50/51)
23600-17032; 135-145; TOYOTA 1HD-T (08/1996-07/2002 HDJ80/100)
23600-17110; 150-160; TOYOTA 1HZ (didn't exist)
23600-17090; 150-160; TOYOTA 1HZ (didn't exist)
23600-17050; 150-160; TOYOTA 1HZ (didn't exist)
6TA1285000; 230-240; TOYOTA 1HD-T (didn't exist)
23600-17020; 145-155; TOYOTA 1HZ-T (didn't exist)
so according to this, the 1HZ-T ran the same crack pressures as the 1HZ at the time of release, makes sense, both had a 10mm IP which have similar test specs (to my untrained eyes). after the 1HZ-T's release, in 1994/95 the Japanese 1HZ models crack pressures appear to have been raised the 7% to current levels, which was only seen in other markets in 1998.
so what will I do? Given i want stock 1HZ-T performance, but that my current 2002 1HZ injectors already live in the newer head and have the slightly higher crack pressure, after all that effort I think I'll just leave them at their designed specs (150-160), but it's nice to no longer have many doubts.
do you agree? anyone have any better ideas?, bare in mind i don't want anything above stock performance and reliability.
