First, the good news: it cranks strong and long and has a fat, bright, strong spark.
If fuel is sprayed into the air inlet duct to the throttle body, the engine will run.
And Yes, I know how dangerous that is.
The fuel tank has been removed and cleaned.
The fuel pump runs and fuel flows out of the hose going into the injector.
I have NOT measured the fuel Pressure as I haven’t been able to rig up a gauge.
When ignition is turned ON and/or cranking the engine, no fuel comes out of the Injector.
The Fuel Injector has the correct resistance as measured with my Fluke 179.
The wiring connector to the Fuel Injector was tested and neither wire (Red/BLK and WHT) had continuity to ground.
With the Ignition Switch ON, the Red/Blk wire had BATT voltage both to the WHT wire and to Ground.
I presume that the ECU controls the Injector by completing the circuit to ground through the WHT wire.
Additionally, when the ignition is turned ON, the fuel pump runs briefly and the stepper motor in the throttle body runs to both limits. (whirrrr whirrr click click chatter chatter)
And Yes, I have already read and re-read EFI 101. Great info there.
CODES
The following Blink Codes are present:
41 Inlet Air Temp Low or High Voltage
47 Idle Air Control Open Load or Short to Ground
51 Injector Open Load or Short Circuit to Battery
55 Diagnostic Lamp Short Circuit to Ground or Battery
41 IAT
The resistance across the terminals on the IAT probe immersed in 68° water
is 2.490k-ohm, close enough for Gov’t work. (Appears the Service Manual is
mistaken in listing the value as ohms instead of K-ohms.)
Measured 5vdc at the IAT connector, Orange wire to ground and to
Purple(violet?).
Checked continuity to ground of both wires and Orange has 3.48k-ohms to
ground and Purple(violet?) has continuity to ground.
I do NOT understand how the Code could be correct if both the Voltage and Resistance are either Correct or very close to Spec.
47 IAC
Checked the resistance across the pins on the IAC per the Service Manual
and the values are pretty close:
PINS Spec Actual Diff
1-2 30+/- 1.2 32.0 +0.8 ohm
2-3 30+/- 1.2 31.7 +0.5 ohm
1-3 60+/- 2.4 63.4 +1.0 ohm
4-5 30+/- 1.2 31.5 +0.3 ohm
5-6 30+/- 1.2 32.3 +1.0 ohm
4-6 60+/- 2.4 63.5 +1.1 ohm
Without knowing where the wires on the connector go, I can’t begin to determine if one is “short(ed) to ground”. And I don’t really understand the definition of “Open Load”.
51 Injector
It has the correct voltage and resistance; it has fuel, it isn’t working. Not a squirt, not a dribble.
Again, I don’t understand the term “Open Load”.
55 Diagnostic Lamp
If I understand correctly, I should get a Check Engine (MIL) light when Codes are present. I have four Codes and there is NO Check Engine light on the instrument panel. Frankly, I’ll worry about that one later, unless it’s a function of a faulty ECU. Can a Dealership bench test the ECU? (NOT to be confused with PDM, Power Distribution Module, which has been repaired and is apparently functioning well.)
As for clearing codes, the battery has been disconnected for days and the same codes reappear. I have replaced the IAT and fuel injector to no avail. Everything else appears to working normally.
I would greatly appreciate ANY ideas or suggestions as to the source of these Codes, how to diagnose the problems and how to go about “fixing” them and getting this vehicle running again.
MaxTorque
