CA2014546C - Automatic starting fluid injection apparatus and method - Google Patents

Abstract

Automatic starting fluid injection systems are useful, for example, to aid in the cold-starting of diesel engines. In the subject invention, a microprocessor under software control is used to controllably inject starting fluid into an engine passageway, such as an intake manifold. During engine cranking, the microprocessor delivers an injection signal to a fluid delivery system to effect starting fluid injection into the engine passageway. When the engine starts, a subsequent injection time is calculated based on the sensed engine temperature.
The microprocessor continues to deliver the injection signal to the fluid delivery system during the subsequent injection time.

Description

2 ~ ~ ~r ~J ~ g Description Automatic Startin~ Fluid Inlection A~paratus and Method Technical F.ield The pre~ent invention r~lates to a system for automat.iaally in-jecting starting fluid into a passageway of an internal combustion engine and, more lo particularly, to an injection system that continuously injects starting ~luid during engine cranking and subsequently, after the engine starts, injects starting fluid for a calculated period of time based on one or more engine parameter~.

Backqround Starting fluids, such as ether, have long been used to aid in cold weather starting o~ internal combustion engines. Typically, llquid ether is injectad into an inlet air ~tream, such as an intake manifQld, where it vaporizes upon contact with the cold air. The air/ether charge is then combined with fuel during fuel in~ection into an engine combustion ch~mhPr. Ether lowers tha temperature at which the mixture in the combustion chamber will ignite and thus shortens the ignition delay period. Engînes usually run best when combustion begins be~ore the piston reaches top dead center in the cylinder. Under cold start conditions without ether, ignition occurs late in the combustion cycle~ or the combustible mixture may not ignite at all. Late ignition can cause a rapid ri~e in the cylinder pres~ure and result in serious engine damage. If one or more engine cylinders fails ko i~nite, the remaining cylinders carry an additional load whi~h reeults in high .
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pressures in the load-carrying cylinders. Engines are designed to operate below a maximum or peak pressure, and exceeding this limit can cause premature engine failure.
Typically, manual systems are used for starting fluid injection. More particularly, a vehicle operator simply uses an on/off switch to activate starting fluid injection whenever desired.
Since these manual systems rely on operator activation, injection i5 highly unreliable and erratic. For example, it is possible for an excessive amount o~ starting fluid to be injected into an engine combustion chamber prior to engine cranking. If this occurs, serious engine damage can result when the combustible mixture ignites in the combustion chamber.
Several automatic systems have been developed to better control starting fluid injection.
One -~uch system is disclosed in U.S. patent number 4,774,916 which issued on February 11, 1987 to Smith.
In Smith, a predetermined volume of starting fluid is repeatedly injected into an engine intake manifold during engine cranking. In~ection of the starting fluid stops when the starter is no longer en~rgized.
However, to eliminate white smoke from engine exhaust and to ensure smooth running during engine warm up, it is desirable to continue injection for a period of time after thP engine starts. White smoke occurs when engine exhaust contains unburned fuel and it is both functionally and aesthetically desirable to eliminate white smoke from the engine exhaust. ~njecting the starting ~luid during this post-crank period lowers the ~lash point of the air/fuel mixture in the engin combustion chamber, th~reby causing the fuel to burn more completely~

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One injection system which provides this desirable post-cranking injection is disclosed in U.S.
patent number 4,202,309 which issued on July 20, 1978 to Burke. In Burke, starting fluid is continuously injected during engine cranking and a predetermined amount of fluid is subsequently injected from a reservoir when cran~ing ceases. Un~ortunately, if an a~tempt to start the. engine fails, the system still in-;ects the predetermined amount when cranking stops.
A subseguent attempt to start the engine can result in engine damage due to an excess amount of starting fluid in the combustion chamber. Furthermore, if the engine starts successfully, the volume of starting fluid subsequently injected is constant and therefore can be excessive or insufficient to solve the aforementioned problems.
The present invention is directed toward addressing the above mentioned problems by continuously injecting starting fluid during engine cranking and subsequently, a~ter the engine starts, injecting starting fluid for a period of time based on one or more engine parameters. If the engine fails to start, injection ceases immediately thereby preventing excessive starting fluid injection. Other aspects, objects and advantages can be obtained frsm a study of the drawings, the disclosure, and the appended claims.

Disclosure of The Invention In accordance with one aspect of the present invention there is provided an apparatus for automatically injecting starting fluid into a passageway of an internal combustion engine. A speed sensor produces a speed signal in response to the speed of the engine. A temperature sensor produces a temperature signal in response to th~ temperature of .: ~ - q .

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the engine. ~ processor receives the temperature and speed signals, calculates an injection time in response to the engine temperatura signal, and produces an injection signal in response to the speed signal for a period of time equal to said calculated injection time. An fluid delivery system receives the injection signal and injects the starting fluid in response to the injection signal~

Brief Descri~tion of The Drawinqs E'ig. la is a schematic illustration of one embodiment of the ; ~ te starting fluid injection syste~.
Fig. lb is a schematic illustration of another embodiment of the 1 -~iate starting fluid injeckion system.
Fig. ~ is a graph of injection time versus engine coolant temperature.
Fig~. 3a and 3b are flowcharts of certain functions performed by one embodiment of the immediate starting fluid injection system.
Figs. 4a and 4b are flowcharts of certain functions performed by an alternate embodiment of the i -~iate starting fluid injection system.
Best Mode For Carrying Out The Invention Referring now to Fig. 1, an embodiment of the i ~iate starting fluid injection system 10 is described for use with a diesel engine (not shown.) A
manually operated three-position switch 12 is connected by an electrical conductor 14 to an electrical power source 16 such as a battery having a potential of ~Vcc. The ~witch 12 is movable between "off", "runl~ and ~Icrank~ positions as denoted by "O", "Rt' and 'IC~', respectively, and is biased from the "crank" to the "run" position by a return spring (not shown). The switch is shown in the "off" position but is movable to the "run" and "crank" positions as illustrated by the dashed lines in Fig~ 1. When the switch 12 is in the "crank" position, electrical power is delivered to a starter (not shown) which cranks t~le engine to induce starting. The switch 12 is further connected to a progralNmable logic device, ~or example a microprocessor 18, by a pair of electrical lQ conductors 20, 22.
Electrical power is delivered to the microprocessor 18 via the electrical conductor 20 when the switch 12 is in the "run" or "crank" positions and further via the electrical conductor 22 when the switch 12 is in the "crank" position, thereby activating the microprocessor 18. The microprocessor 18 is also connected by an electrical conductor 26 to a source of low electrical potential 28 such as the negative terminal of a battery or chassis ground. The microprocessor 18 can be any one of numerous commercially available microprocessors; however, in the preferred embodiment the microprocessor 18 is a model HC11 manufactur~d by Motorola Inc. of Phoenix Arizona. The microprocessor 18 is programmed to selectively control delivery of the ~tarting fluid to the engine in response to sensed parameters, a~
described later.
An engine coolant sensor 30 is electrically connected ~o the switch 12, the microprocessor 18, and the source of low electrical potential 28 by electrical conductors 20, 32, 26, respectively. In the pref~rred embodiment the coolant ensor 30 produces a digital temperature signal on the conductor 32 in response to the engine coolant temperature; however, it is ~oreseeable and within the scope of the :' , ' :
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invention to use a sensor that produces a pulse-width-modulated or analog signal, for example.
Furthe~nore, sensing coolant temperature as opposed to engine block temperature, for example, is desirable for improved accuracy and i5 considered more representative of "engine temperature". In the pr~ferred embodiment, the coolant sensor 30 is capable of accurately measuring coolant t~mperatures ranging from -40 C to ~121 C. Sensors of this type are common in the art; therefore, a more detailed description is not provided herein.
~ l en~ine speed sensor 34 is connected to the switch 12, the microprocessor 18, and the source of low electrical potential ~8 by respective electrical conductors 20, 36, 26. The speed sensor 34 can be any type of sensor that accurately produces an electrical signal in response to engine crankshaft speed~ However, in the preferred embodiment, the speed sensor 34 is mounted on an engine ~lywheel housing (not shown) and produces a digit21 speed signal on the electrical conductor 36 in response to the speed of a ~l~wheel 37 mounted on the engine crank shaft (not shown3. Engine speed as referred to hereinafter is the speed of the engine crankshaft in revolutions per minute (rpm)~ ~urthermore, in the preferred embodiment, the speed sensor 34 is capable of accurately measuring engine speed over a range from 15 ~o 2000 rpm.
A fluid delivery system 3B~includes a pair 0 of pressurized canisters 40a, 40b containing starting fluid such as ether. ~wo canisters 40a, 40b are provided to reduce the likelihood of running out of starting fluid during an injection cycle. An injection cycle, as referred to hereinafter, is the cycle of injection starting when engine cranking 2 ~

begins and ending when injection is stopped, as explained below. The fluid delivery system 38 injects starting fluid into an engine passageway 42, such as an intake manifold, in response to an injection signal produced by the microprocessor 18. The fluid delivery system 38 further includes a pair of solenoid operated valves 44a, 44b. The solenoid operated valves 44a, 44b have intake ports 46a, 46b coupled to respective canisters 40a,40b, respectively. Each o~ the solenoid operated valves 44a, 44b is normally biased to a "closed" position by a return spring 48a, 48b.
A pressure-actuated shuttle valve 50 has intakQ ports 51a, 51b connected to exit ports 52a, 52b of the solenoid op~rated valves 44a, 44b by respective fluid conduits 54a, 54b. Shuttle valves of this type are common in the art and therefore will not be described in detail herein. An injection nozzle 56 is disposed in the engine passageway 42 for dispensing starting fluid into the passageway 42. The injection nozzle 56 is connected to an exit port 58 of the shuttle valve 50 by a fluid conduit 60.
A pair of solenoids 62a, 62b are provided for controlling the solenoid operatPd valves 44a, 44b, respectively, in r~sponse to the injection signal produced by the microprocessor 18. More particularly, the solenoids 62a1 62b ~re mechanically conne~ted to the respective solenoid operated valves 44a, 44b~ and electrically connected to the micropro¢assor 18 by respsctive electrical conductors 64a, 64b. Ths microprocessor 18 controllably delivers an injection signal to the solenoids 62a, 62b over the electrical conductvrs 64a, 64b to effect starting fluid injection into the engine passageway 42.
A pair of electrical switches 66a, 66b are connected to the source potential ~Vcc by respective f~ r~ ,, electrical conductors 67a, 67b and further to the microprocessor 18 by respective electrical conductors 68a,68b. Each switch 66a, 66~ is associated with one of the canisters 40a,40~, respectively. The switches 66a, 66b are advantageously positioned to be open when the canisters 4 oa, 4Ob are in place, as shown. When one of the canisters 40a, 40b is removed, the corresponding switch 66a, 66b closes and electrical power is delivered to the microprocessor 18 via the respective conductor 68a, 68b. More specifically, the conductors are connec~ed to separate input ports 69a, 69b of the microprocessor 18 such that the microprocessor 18 is activated whenever one of the canisters 4Oa, 4Ob is removed. When the microprocessor 18 is activated in this manner, the microprocessor memory is updated to indicate that the canister 40a, 40b has been replaced.
A warning system 70 is electrically connected to the microprocessor 18 for providing a warning when one or both o~ the pressurized canisters 40a, 40b is empty. In the preferred embodiment, the warning system 70 includQs first and second warning lights 72a, 72b cooperatively associated with the first and second canisters 40a, 40b, respectively, and an audio warning device 74 such as a buzzer. The microprocessor 18 selectively delivers electrical signals on the electrical conductors 76a, 76b in response to receiving an empty canister signal, thereby activating the light 72a, 72b corresponding to the empty canister 4Oa~ 40b. Xn the event that both canisters 40a, 40b are empty, the microprocessor 18 produces electrical signals on all the conductors 76a, 76b, 78 thereby simultaneously activating both lights 72a, 72b and the audio warning device 74.

Industrial Applicability Timed Method Referring now to Figs. 3a and 3b, an embodiment of software for controlling the microprocessor 18, hereinafter referre.d to as the timed method, is illustrated by a flowchart. The micropro~essor 1~ i5 activated whenever the key switch 12 is positioned in either the "run" or "crank"
positions. At times when th~ microprocessor 18 is activated and staxting fluid is not being injected, the microprocessor 18 is switched to a ~Ipassive~l mode wherein all input and output circuits are monitored for fault conditions.
Subsequent to microprocessor activation, an injection routine 200 begins. In the first step of the injection routine 200, the switch 12 i5 monitored in the block 201 to determine if the engine is cranking. More particularly, when the key switch 12 is in the crank position, the conductor 22 is at the source voltage potential ~Vcc.
The microprocessor 18 .'---; n.~ in the passive mode until engine cranking is detected in the block 201, at which time control is pas~ed to the decision block 202. In the decision block 202 the engine temperature TE is determined by monitoring the coolant sensor 30. Subsequently, the engine temperature TE is compared to a predetermined bias B1. If the engine tem~erature TE is greater than the bias Bl, the injection routine 200 stops and the microprocessor 18 returns to the ~Ipassive~ mode. Otherwise, control is passed to the decision block 204. In the preferred embodiment, the bias Bl is set at 10~ C; however, it is foreseeable that other values can be selected for the bias Bl.

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In the decision block 204, the engine speed sensor 34 is monitored to determine engine speed NA.
The engine speed NA is continuously monitored in this manner until it exceeds a preselected bias B2, thereby preventing starting fluid in~ection at engine speeds NA below the bia~ B2~ Otherwise, if injection is allowed as soon as the ~e~ switch 12 reaches the "crank" position, it is possible for an excessive amount o~ starting fluid to be injected prior to engine cranking and ignition. If this occurs, an excessive amount o~ starting ~luid can be injected into the engine. When the mixture in the combustion chamber subsequently ignites, engine damage can result as previously explained. In the preferred embodiment, the bias B2 is set to 30 rpm; however, depending on the operational characteristics of the engine in question other values can be selected ~or the kias B2.
When the engine speed NA reaches the bias B2, control is passed to the block 206 where a starting fluid flow rate FR is calculated as a function of the engine coolant temperature TE. More particularly, a look-up table in microprocessor memory is accessed to determine a flow rate FR through the nozzle 56 for the measured engine temperature TE.
Because the rate of flow through the injection nozzle 56 varies with temperature by as much as a factor of three, a constant flow rate FR cannot be as~umed. The look-up table is empirically determined by measuring starting fluid flow rates through the noz~le 56 over a range of operating temperatures. The flow rate ~R is used to calculate the volume of starting fluid r~r~;ning in a canister 40a, 40b, as explained below.
In the block 208 an elapsed time timer ET is initialized to zero and started. The elapsed time ET
i~ used in conjunction with the flow rate FR to calculate the volume remaining in the canister 40a, 40b currently being used for injection.
Subsequently, starting fluid injection begins in the block 210. More particularly, the microprocessor 18 selectively produces the injQction .~ignal on one of the conductors 64a, 64b thereby actuating the respective solenoid controlled valve 44a, 44b~ One of the canisters 40a, 40b is repeatedly utilized for injection until it is empty, at which time the other canister 40a, 40b is thereafter utilized for injection. This strategy assures that a supply of starting fluid is always available during the injection cycle.
Thereafter, in the block 212, the volume remaining VR in the canister 40a, 40b currently in use is calculated using the following equation:
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VR = LVR - (FR*E~) where VR is the volume remaining in the canister 40a, 40b, LVR is the volume remaining after the last injection cycle, FR is the flow rate through the nozzle 56, and ET is the elapsed time for the current injection cycle. In the preferred e~bodiment the canisters 40a, 40b each have an initial volume of 810 ml; therefore, the last volume remaining LVR is initially set to 810 and is updated at the end of each injection cycla. This strategy assures that a supply of starting fluid is always available during injection.
In the decision block 214, the volume remaining VR is compared to a preselected bias B3 to determine if the canist~r 40a, 40b being used fox injection is empty. In the preferred embodiment the bias B3 is calculated as a function of the engine ,. ,: , : .

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~' ' ' ' ' coolant temperature TE and flow rate FR. More particularly, the engine coolant temperature TE is used to determine the flow rate FR, as explained previously. Subse~uently, the volume of starting fluid that would be injected over a two minute time period at the flow rate FR is calculated. ~he bias B3 is set to this calculated volume, thereby assuring that, at a ~;n1 , the canister 40a, 40b contains a two minute supply of starting fluid.
If the canister 40a, 40b currently being utilized for injection is empty, control is passed to the block 216 where an empty-canister flag is set in microprocessor memory for that canister 40a, 40b. More particularly, a current-use flag is set in microprocessor memory for the canister 40a, 40b currently being utilized ~or injection. When the canister 40a, 40b currently being used for injection is empty, an empty canister flag is set for that canister 40a, 40b and the microprocessor memory is updated such that the other canister 4Qa 4Ob is thereafter used for inj~ction. Furthermore, the light 72a, 72b associated with the empty canister is activated. More speci~ically, the microprocessor 18 produces a high potential signal on the conductor 76a, 76b associ~t~d with the empty canister, thereby activating the respective warning light 72a, 72b.
Subsequently, control i~ passed to the dPcision block 218 to determine i~ both canisters 40a, 40b are empty. I~ empty-cani~ter fla~s are set ~or both the canisters 40a, 40b/ control is passed to the block 220 causing the microprocessor 18 to produce high potential signals on the conductors 76a, 76b, 78, - thereby ac~ivating both of the warning lights 72a, 72b and the audio warning deYice 74. In the preferred embodiment, injection continues even i~ both caniskers 40a, 40b are empty; however, the so~tware and vehicle hardware can be modified to shut down the engine, for example, when this situation occurs. Injection is allowed to continuQ in this instance because a safety factor is included in the flow rate FR calculation;
therefore, the caniste:r 40a,40b could still contain a small supply o~ staxting fluid.
If the othar canister 40a, 40b is not empty, control is passed to the block 222. In the block 222, the elapsed timer ET is initialized and restarted.
Thereafter, in the block 224, the microprocessor memory is updated such that other canister 4Oa, 4Ob becomes the current-use canister. In the block 226, the last volume remaining LVR is set to a Bias R4 which corresponds to the volume of a full canister 40a, 40b. As mentioned previously, the canisters 40a, 40b have a volume of 810 ml in the preferred em~odiment.
Control is then passed to the decision block 228 where the engine speed NA is compared to a pair of predetermined biases B5, B6. If the engine speed NA
is less than the bias B5 or greater than the bias B6, control is passed to the block 230 causing injection to stop. The bias B5 is selected such that injection stops whene~er the engine speed ~alls below a preselected speed. In the preferred embodiment, the bias B5 is set at 15 rpm: however, other values can be chosen for this bias. This strategy prevents starting fluid ~rom being injected into a stalled engine. The bias B6 is selected such that injection stops if the engine speed NA exceeds a preselected value. This is done to prevent engine overspeed which occurs when too much fuel is being injected into the engine. In the preferred embodiment, the bias B6 is set at 2000 rpm;

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however, it is foreseeable to select different values ~or this ~i engine speed~
If either of these conditions is meet, control is passed to the block 230 causing injection to stop~ Thereafter, in the block 232, the variable last volume remaining LVR is updated using the following equation:

VRt LVR(t~ E~*FR) where LVRt is the volume remaining in the current-use canister 40a, 40b after the present injection cycle and LVR(t 1) is the volume remaining a~ter the previous injection cycle.
If neither of these conditions i~ met, control is passed to the decision block 233 to check if the engine has started. To determine if the engine has started, the switch 12 and speed sensor 34 are simultaneously monitored. If the switch 12 is in the "on" position and the speed sensor 34 is producing a speed signal greater than the bias B2, it is assumed that the engine has started. When the engine starts, control is passed to the block 234 which forms part of a subsequent-injection control loop 236.
The subsequent-injection control loop 236 function6 ~o inject starting fluid for a period of time based on engine temperature TE subsequent to the - engine starting. More specifically, a subsequent injection time IT i~ calculated in the block 234 u~ing the following injection formula:
IT = 38 - (2.3 * TE) where TE is the measured engine temperature. The injection formula follows the curve illustrated in ei~ 6 Fig. 2 and is empirically determined for a specific engine. As mentioned previously, if ignition of the air~fuel mixture occurs late in the combustion cycle, a rapid rise in cylinder pressure can occur and result in serious engine damag~. Starting fluid, and ether in particular, lower the temperature, and therefore the time, at which the air/fuel mixture in the cylinder will ignite. The amount of time that starting fluid n~eds to be injected at a given temperature to prevent rapid pressure rises and ensure smooth starting is dete~mined by monitoring engine cylinder pressuxe durin~ starting at that particular temperature. Starting fluid is injected for a period of time suf~icient to ensure the cylinder pressure does not eYcee~ the maximum pressure allowable for safe engine operation. These ~easurements are repeated over a variety o~ temperature~ and integrat2d to generate a table of engine temperature TE versus injection time IT.
Thereafter, a subsequent injection timer TA
is initialized to zero and started in the block 237.
The blocks ~38 to 252, are the ~ame as the blocks 212 to 226 and serve to reduce the likelihood o~ running out of star~ing fluid during injection. Subsequently, control is pas~ed to the decision block 254 where the engine speed NA is compared to the biases B5 a~d B6 as explained abovs. I~ engine speed exceeds the bias B6 or falls below the bia~ B5, control is p~.~se~ to the block 256 causing injection to s~op and then to the block 258 where the variable last volume r~ ~;n;ng LVR
is updated. Otherwise, control ic pa~sed to the ~lock 260 where the sub~e~uent-injection timer TA is compared to the calculated injection time IT. I~ the subsequent injection timer T~ i~ less than the calculated injection time IT, injection continues and , , 2 ~

Injection continues as previously described until the subsequent injection timer TA equals or exceeds the calculated injection time IT. When thi~ occurs, aontrol is passed to the block 256 causing injection to stop.

Sensor Method Referring now to Figs. la, 4a and 4b, an alternate embodiment of the in~ection system 10 and associated software for controlling the microprocessor are discussed. This embodiment differs from the previously described emboA; ?nt with respect to determining when the canisters 4oa, 4Ob are empty.
This em~odiment, hereinafter referred to as the sensor method, utilizes a starting sensor RO preferably located in the air intake manifold 42 at a location downstream from the injection nozzle 56. In the preferred embodiment, the starting fluid sensor 80 includes a resistive element 82 disposed in the manifold 42. The electrical resistance of the element 84 changes in response to the presence or absence of starting fluid in the passageway 42. A conditioning circuit 84 is electrically connected to the resistive element 82 and produces a pulse-width-modulated signal having a duty cycle responsive to the resistance of the element 82. Thi~ signal is then delivered to the microprocessor 18 via an electrical conductor 86. It is foreseeable that this function could also be performed by sensing d(flow)/dt, d(pressure)/dt, etc.
in the fluid conduit 60.
Con~inuing with the discusslon of Figs, 4a and 4b, the blocks 301 to 306 can be understood by referring to the previous description of blocks 201, 202, 204, and 210 in Fig. 3a. In the decision block 308, the starting fluid sensor 80 is monitored to f 308, the starting fluid sensor 80 is monitored to determine if the pressurized canister 40a, 40b currently being utilized is empty. If the canister ~oa, 40b is empty, control is p~SQ~ to the block 310 causing the microproces~or 18 to deli.ver the injection signal to the other canister 40a, 40b. A~ in the timed method, a current-us~ ~lag i~ set in microproces~or memory for ~he canister 40a, 40b currently being used ~or injection. When a canister becomes empty, an empty-canister flag is set in microprocessor memory ~or that canister 40a, 4Ob and the microproces~or is updated such that the other canister 4Oa, 40b b~comes the current use canister.
Thereafter, in the block 312, the microprocessor produce~ a hig~ slgnal on one of the conductors 7~a, 74b, thereby activating the warning light 72a, 72b associat~d with the empty canister 40a, 40b.
In the deci ion block 314, the starting fluid ~ensor 80 is a~ain monitored to determine if the new current-use canister is also empty. If both canisters 40a, 40b are ~mpty, aontrol is passed to the block 316 causing the microproce~or 18 to produce high signal on the conductors 76a, 76b, 78 thereby activating both o~ the warning lights 72a, 72b and the audio warning device 74. Subsequently, control is p~se~ to the block 318 causing injection to stop.
If the new current use canister is not empty, control is pas~ed to the deci ion block 320.
~he r~ --n;ng portion of the flowchart can be understood by referring the previous descriptions of the block~ 228, 23 , 234 254, 256 and 260 o~ the timed method and the block 310 to 316 of the s~nsor method.

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Claims (8)

1. An apparatus for automatically injecting starting fluid into a passageway of an internal combustion engine, comprising:
speed sensor means for producing a speed signal in response to the speed of said engine;
temperature sensor means for producing a temperature signal in respond to the temperature of said engine;
processor means for receiving said temperature and speed signals, calculating an injection time in response to said engine temperature signal, and producing an injection signal in response to said speed signal for a period of time equal to said calculated injection time; and, fluid delivery means for receiving said injection signal and injecting said starting fluid into the engine passageway in response to said injection signal.

2. The apparatus set forth in claim 1 including:
means for cranking said engine;
means for producing a cranking signal in response to said engine cranking, and, wherein said processor means continuously produces said injection signal in response to simultaneously receiving said cranking and engine speed signals and subsequently produces said injection signal for said calculated injection time in response to receiving said speed signal absent said cranking signal.

3. The apparatus set forth in claim 1, wherein said fluid delivery means includes:
pressurized canister means for containing said starting fluid;
an injection nozzle mounted in said engine passageway; and, a solenoid operated valve having an intake port coupled to said pressurized canister means, an exit port coupled to said injector nozzle, and being adapted to receive said injection signal and inject said starting fluid into said engine passageway in response to said injection signal.

4. The apparatus set forth in claim 1, wherein said fluid delivery means includes:
an injection nozzle mounted in said engine passageway;
first and second pressurized canister means for containing said starting fluid;
first and second solenoid operated valves having first and second intake ports respectively fluidly coupled to said first and second pressurized canister means, first and second exit ports fluidly coupled to said injection nozzle, and being adapted to receive said injection signal and regulate flow between said intake and exit ports in response to said injection signal;
detector means for producing an empty canister signal in response to one of said first and second pressurized canisters being empty wherein said processor means controllably delivers said injection signal to one of said first and second solenoid operated valves and upon receiving said empty canister signal controllably delivers said injection signal to the other solenoid operated valve.

5. The apparatus set forth in claim 4 wherein said detector means includes:
a sensor disposed in said engine passageway and being adapted to produce said empty signal in the absence of said starting fluid.

6. The apparatus set forth in claim 4, wherein said detector means includes:
timer means internal to said processor means for accumulating the amount of time that said one solenoid operated valves receives said injection signal and producing an accumulated time signal in response to said accumulated time; and wherein said processor means receives said accumulated time and temperature signals, calculates the volume of starting fluid remaining in one of said pressurized canisters in response to said temperature and accumulated time signals, and produces said empty signal in response to said calculated volume being less than a preselected reference.

7. An apparatus for automatically injecting pressurized starting fluid into a passageway of an internal combustion engine, comprising:
a three position switch having off, crank, and run positions;
switch sensor means for producing crank and run signals in response to said switch being in said crank and run positions, respectively;
speed sensor means for producing a speed signal in response to the speed of said engine;
temperature sensor means for producing a temperature signal in response to the temperature of said engine;

processor means for receiving said speed and crank signals, producing an injection signal in response to said speed and crank signals, receiving said run signal and temperature signals, and thereafter producing said injection signal for a period of time based on said temperature signal and in response to receiving said run signal: and, fluid delivery means for receiving said injection signal and injecting said starting fluid into the engine passageway in response to said injection signal.

8. A method for automatically injecting starting fluid into a passageway of an internal combustion engine, comprising the steps of:
sensing the speed of said engine;
sensing the temperature of said engine;
calculating an injection time in response to said sensed engine temperature; and, injecting said starting fluid for said calculated injection time in response to said sensed engine speed.