A multi meter can be used yes but not every connector is gouing to let you stick a probe in there without damaging the connector(pigtail) seal.
Higher fuel pressure with all other variables fixed would cause more fuel dumping out the injectors creating a richer mixture.
ALarm theory was based on info below:
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Bulletin No.: 02-06-05-004b
Date: February 14, 2006
INFORMATION
Subject:
Misfire DTCs P0300, P1380, P1381 and Catalytic Converter Damage Due to Installation of Alarm Systems
Models:
2006 and Prior GM Passenger Cars and Light Duty Trucks
2006 and Prior HUMMER H2, H3
2006 and Prior Isuzu Light Duty Trucks
Supercede:
This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 02-06-05-004A (Section 06 - Engine/Propulsion System). General Motors Engineering, in an effort to determine the root cause of catalytic converter damage, has determined that aftermarket alarm systems incorrectly installed in vehicles have the potential to cause misfire codes and damage to the converter. These alarm systems use a circuit interrupt which utilizes the ignition circuit on the vehicles.
These alarm systems utilize mechanical relays and normal vehicle movement can trigger these relays to engage and disengage the ignition circuit while the vehicle is in motion. These disruptions of the ignition circuit, which occur in milliseconds, may cause more fuel to be commanded. Overtime, this dumping of fuel on and off again can cause misfire codes and ultimately damage the converter assembly.
Important: Engineering could not identify any alarms that utilize solid state circuitry that would eliminate this concern. Because of this, it has been determined that all alarm systems must be routed through the starter circuit in order to avoid this condition.
Dealers must be aware of this issue and take note of the wiring on vehicles with alarm systems that come in for repair, particularly for catalytic converter damage that seem to have no known root cause.
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My thought was depending on the design of the relay that they sensitive to g-force(speed bumps, rough roads and such)that the alarg ignition interrupt might chatter causing intermitent ignition or injector glitchs.
What I ment by orientation by axis is that if you were to for example take a home electrical circuit breaker in your hand held it up right with the switch in the closed(on not tripped) position and bang it down on a solid object parts inside would react to the g-force and cause it to trip it self. If you did the same thing again but held it sideways it may not do it becuase the parts cannot pivot the same direction as before to same gforce direction. Hence if you reorient the alarm from being layed out flat to being upright in postion or vice versa that kind of problem could be prevented. But becuase the vehicle is still when parked I don't think it would apply.
Taking a breath....
Check these ground straps for damage and such when you have time, maybe got damaged when the tranny came out:
G101 Sheet Metal at RH front Wheelhouse
G102 RH front of Engine Block, near Damper Pulley
G103 RH front of Engine, near Thermostat Housing
G104 RH top of Cylinder Head, near center
G105 RH front of Engine Block
G107 LH front Fender (Auxiliary Battery Ground)
G110 RH rear of Engine Compartment, below Heater Lines Gill RH rear of Engine
G112 RH front of Engine Compartment, below Underhood Reel Lamp
G113 On Radiator Support, near LH Headlamp
G150 (VIN M, R, J) RH front of Engine, near Thermostat Housing
ECT = Engine collant temp sensor
DESCRIPTION
The engine coolant temperature sensor is a thermistor (a resistor which changes value based on temperature) mounted in the engine coolant passage. Low coolant temperature produces a high resistance 100,000 ohms at -40°C (-40°F) while high temperature causes low resistance 70 ohms at 130°C (266°F).
OPERATION
The VCM supplies a 5 volt signal to the engine coolant temperature sensor through a resistor in the VCM and measures the voltage. The voltage will be high when the engine is cold. The voltage will be low when the engine is hot. By measuring the voltage, the VCM calculates the engine coolant temperature. Engine coolant temperature affects most systems the VCM controls.
The scan tool displays engine coolant temperature in degrees. After engine start-up, the temperature should rise steadily to about 9O°C (194°F) then stabilize when thermostat opens. If the engine has not been run for several hours (overnight), the engine coolant temperature and intake air temperature displays should be close to each other. When the VCM detects a malfunction in the Engine Coolant Temperature (ECT) sensor circuit, the following Diagnostic Trouble Code (DTC) s will set:
* DTC P0117 circuit low.
* DTC P0118 circuit high.
* DTC P0125 excessive time to Closed Loop.
* DTC P1114 circuit intermittent low.
* DTC P1115 circuit intermittent high.
The above DTCs contain a table to check for sensor resistance values relative to temperature. Refer to Specifications. See: Computers and Control Systems\Specifications
The Mass Air Flow (MAF) sensor measures the amount of air which passes through it. The VCM uses this information to determine the operating condition of the engine, to control fuel delivery. A large quantity of air indicates acceleration. A small quantity of air indicates deceleration or idle.
The scan tool reads the MAF value and displays it in grams per second (gm/Sec). At idle, it should read between 5-7 gm/Sec on a fully warmed up engine.
Values should change rather quickly on acceleration, but values should remain fairly stable at any given RPM. When the VCM detects a malfunction in the MAF sensor circuit, the following Diagnostic Trouble Code (DTC) s will set:
* DTC P0101 system performance.
* DTC P0102 frequency low.
* DTC P0103 frequency high.
Intake air temp.
PURPOSE
The Intake Air Temperature (IAT) sensor is a thermistor which changes value based on the temperature of air entering the engine.
OPERATION
Low temperature produces a high resistance 100,000 ohms at -40°(-40°F). A high temperature causes low resistance 70 ohms at 130°C (266°F). The VCM supplies a 5.0 volt signal to the sensor through a resistor in the VCM and measures the voltage. The voltage will be high when the incoming air is cold, and low when the air is hot. By measuring the voltage, the VCM calculates the incoming air temperature. The IAT sensor signal is used to adjust spark timing according to incoming air density.
PURPOSE
The Manifold Absolute Pressure (MAP) sensor responds to changes in the intake manifold pressure. The pressure changes as a result of engine load and speed. The map sensor converts this to a voltage output.
OPERATION
A closed throttle on engine coast down would produce a relatively low MAP output voltage. A wide open throttle would produce a high MAP output voltage. This high output voltage is produced because the pressure inside the manifold is the same as outside the manifold. The MAP is inversely proportional to what is measured on a vacuum gage. The MAP sensor is used for the following:
* Altitude determination.
* Ignition timing control.
* Exhaust Gas Recirculation (EGR) diagnostic.
* Speed density fuel management default.
Wide band sniffing is a smog test with tailpipe probe that is capable of measuring various exhaust gases at a wide range(1-100%) instead of narrow range(say 1-50%)
Something to that effect.
High oil consumption with no dripping can indicate it is being burned in the cylinders thru busted head gaskets or valve seals. If it was big enough to see out a tail pipe it would probably burn all the time at any speed if it were gaskets. If you WOT (wide open throttle) and let it close and saw oil burn during deacceleration only could be valve seals. If it leaks outside it could be hidden if it drips onto hot components(exhaust manifold while running).
top that and your coolant reservoir to the suggested level marked on the container and keep an eye on them.
You could probably ignore the look of the old crank sensor. It is supposed in a dry area but oil residue and condensation can get milky.
Thirsty...
Milk does a body good. Especially at a rate of 1/2gallon+ a day
The seems like a lot of oil lost between changes without external leaks.
In case I missed it how are the plugs fouled. Oil? black sooty? colored deposits?
Can you post pics?
At this point it might be wise to save when you can for a good scanner that can do a memory dump to post readouts here. It would provide all the sensor data for analysis. I hate to see you keep spending on parts. I still have more details but enough for now
Once the brake lead was removed from the frame the brake lights worked again. I'll have to try that again after the truck is running right.
) laptop and I'd have a bigger display with so much more info and costumizable displays and management of data. And I can mount a laptop for other uses in the cab for $250. For me to much is never enough.
