Injector flow rate (long post)

[Zublin, Bryan (SD-MS)]

Some people on the list were asking about flow rates of various injectors 
from Toyota engines.  Here is some data from the 22RTE engine.


I have measured the flow rate of four injectors from a Toyota 22RTE engine, 
from a 1986 truck (estimated year).  This is a turbo charged version of the 
22RE, with the CT20 turbo.


DATA

Tested by:  Bryan Zublin
Date of test:  January 1992.
Location:  Poway, California, USA

Injector part number:  Toyota 23250-35020.
Gasoline:  Mobil Super+ unleaded, 92 octane (min), color yellow-green.
Gasoline density:  0.75 grams/mL.
Fuel pressure:  38 psi.
Air temp:  16 to 18 deg C.
Injector current:  1.45 amps.
Duration of test:  60 +/- 0.5 seconds.
Number of trials:  4 or 5 per injector.

Here is the data for each injector (following cleaning):

#1:  298, 296, 299, 297, 297;  avg = 297.4 mL/min.
#2:  307, 307, 307, 307;       avg = 307.0 mL/min.
#3:  296, 297, 297, 298, 298;  avg = 297.2 mL/min.
#4:  299, 301, 301, 301;       avg = 300.5 mL/min.

Note:  mL/minute is the same as cc/minute.


NOTES

The Bentley Service Manual for the Toyota Pickup and 4Runner (published 
1988) lists the injector flow rates as shown below.  I believe that this 
information is NOT correct.

Engine     Year           Flow                   Max delta between injectors

22RE       1984-1986      160-200 cc/min             6 cc
22RTE      1985-1987      160-200 cc/min             6 cc
22RTE      1988           260-320 cc/min             8 cc

This information conflicts with the 1987 and 1988 Toyota Factory Service 
Manual, which lists the flow rate for the 22RTE as 260 to 320 cc/min.  Also, 
there are only two injector part numbers listed for the production run of 
this engine, with the most common on model years 1986 through 1988.

Manufacture Date                     Injector Assembly Number

8501-8508 (model year 1985)          23209-35010
8508-8808 (model years 1986-1988)    23209-35020

The assembly contains the grommet and O ring, so the part number is 
different that the number on the injector itself.  It appears that I have 
the later injectors.

It is interesting to note that the specs on each injector are quite wide 
(around +/- 10% of the center), while the spec on the variation between 
injectors is quite tight (around +/- 3%).  This would imply that the 
injectors are matched in the factory as a set before being installed on the 
engine.


TEST PROCEDURE

The injector was turned on for 60 seconds and the fuel was collected in a 
beaker.  The fuel and beaker were then weighed on a triple beam Ohaus 
balance and the volume was calculated based on the density of the fuel.  The 
density of the fuel was previously measured using three different containers 
(a 300 mL beaker, 10 mL graduated cylinder, and a 100 mL volumetric flask). 
 The three measurements were 0.747, 0.75, and 0.753 grams/mL.  The average 
is 0.75 grams/mL.

Each injector was tested 5 times, and then cleaned with Red Line SI-1 
Injector & Valve Detergent.  The injectors were then tested 4 or 5 more 
times each.  Cleaning the injectors improved the flow rates of all 
injectors, with the most significant change occurring to injector #1 (16% 
increase).


TEST SETUP

Fuel Reservoir
    |
Fuel Pump (1)
    |
Pulsation Damper (2)
    |
Fuel Filter (3)
    |
Fuel Filter (4)
    |
Pulsation Damper (5)
    |
Fuel Rail (6)
    |
    |---- Fuel Injectors (7) --- Hose --- Beaker
    |
    |---- Pressure Gauge (8)
    |
Pressure Regulator (9) ---- Reference port (10) (vent to atmosphere)
    |
Return to Fuel Reservoir


(1) Fuel Pump:  from a 1978 Datsun 280Z, the type that mounts external to 
the gas tank.
(2) Pulsation Damper:  came with the fuel pump.
(3) Fuel Filter:  for Nissan / Datsun cars, Puraltor PF-3128.
(4) Fuel Filter:  the stock Toyota fuel filter for the 22RTE engine.
(5) Pulsation Damper:  the stock Toyota part, mounted to the start of the 
fuel rail.
(6) Fuel Rail:  from the same engine.
(7) Fuel Injectors:  from the same engine, part number marking 23250-35020.
(8) Pressure Gauge:  from Napa Auto Parts, PN 700-1487.
(9) Pressure Regulator:  from the same engine, mounted to the end of the 
fuel rail.
(10) Reference Port:  this is normally connected to the intake manifold of 
the engine.  It was left unconnected and vented to the atmosphere for this 
test.