2.4L Bridgeport EFI issues
09-05-2012, 11:42 AM
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2.4L Bridgeport EFI issues
Hey there, tryin to get the picklefork runnin for this weekend. Workin with an 86' 2.4L 245hp Bridgeport motor (Merc). Setup with the EFI Horn/Intake mani on the stock block. First couple issues, gettin very low vacuum from crank case to open fuel pres. regulator and the port for the ecu. Thats the first issue. Second issue is the fuel injectors aren't firing, got 12v to both wires but no ground. Color codes on the motor are red/yllw and the injectors are paired, from the top- brwn/wht, next two blue/wht, last 2 grn/blk. To get the injectors to fire im pretty sure im looking for a ground on the non red/yllw wires. Got the right ecu, 11350A7. TPS tested ok also. I did locate the purple wire for the alarm/warning system. Someone patched a diff harness to the motor so that wire is open where there is normally a motor plug, i think this is just for the audible alarms and water sensor. My big goal is make it run first then hookup alarms, might need to be tied in first though? I was putting cowling back on to leave last night an heard a pop...such as a hot wire hitting ground, re checked that purple wire now i got .01 volts lol. HELP PLEASE!!
09-05-2012, 12:16 PM
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Probably have better luck on Scream and Fly. Some good OB gurus there. Good luck.
09-07-2012, 09:50 AM
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Alright these guys are stumped on scream an fly i guess, not a single suggestion yet, feel like i do decent for only 25 myself seeing as how no one has any input. Well for others reading im starting with replacing both the motor and the boat side harness. Someone patched a harness from the previous carbed pwr head(same motor), to the current efi harness. Thinkin this might be why my fuel injectors arent gettin a signal, also lookin into a new stator as this ones in sad shape, some grn in the wires from charge wires on the stator and a few others. Few options i can think of, pull an send to CDI for repair or what about the other companies i been seein about? Such as Bracodo, i need to compile a little more info so i know where the decent places are for rebuild stuff on this motor, not everyday we work on the 2.4L BP motors. Little more on the motor i've also shot it with ether just a time or two to make sure we're not havin other issues, pops off. Not trying to run a 2 stroke on ether though haha. Seems that it has most of the sensors bypassed. I know that the idle stabilizer has been removed, not sure how the wires have been handled yet i just know its not on there, found the two blocks where the sensors all connect together before going to ecu an warning horn. Also missing Air temp sensor behind the tilt packs, could this be the sensor telling my ecu no fire? Not sure if its a naturally open circuit an closes to ground w high temp? Little help here please guys, like i said just 25yrs old an doin this for 7 yrs now just need a little help from the skilled techs who have been doin this a little longer or just focus on Mercs only. Also is there a better book cuz i know the wiring code on my motor is diff, usin Merc outboard SELOC manual 1408 (65-89 2 stroker 90-300hp Inc fuel inj models). Any help is greatly appreciated!
Cody
Cody
09-07-2012, 12:34 PM
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Disclaimer - I am not a mechanic - I only play one in the evenings and on weekends.
The very first thing I would do is test the compression on the motor real quick to make sure there are no problems there. Then lube the cylinders with a little two stroke oil so you are not beating them up while playing. Note that they do make starting fluid for two strokes that has oil in it. I assume you are sure that you have strong spark on all cylinders and you beleive that the injectors do not work because you do not smell gas.
I had an efi harness on my 97 carbed 225 and it plugged directly into the 1999 EFI's with no injection problem. I know it is not the same motor but I do not think that there is a wire in the harness that tells the injectors to fire. And, how do you know they are not firing because of an electrical issue?? Why not a fuel pump, fuel line, old fuel or tank issue. Cut the line and the tank out of the equation by hooking up a portable can straight to the engine using fresh gas. Give that a shot and see what happens. After that you will have to work upstream to the mechanical fuel pump (on the lower port side of the engine if it is the same as mine) etc. Give me your email address and I will shoot you a fuel/wiring diagram of a mercury EFI motor. May not be the same exact diagram but it will give you a general idea of the set-up.
The very first thing I would do is test the compression on the motor real quick to make sure there are no problems there. Then lube the cylinders with a little two stroke oil so you are not beating them up while playing. Note that they do make starting fluid for two strokes that has oil in it. I assume you are sure that you have strong spark on all cylinders and you beleive that the injectors do not work because you do not smell gas.
I had an efi harness on my 97 carbed 225 and it plugged directly into the 1999 EFI's with no injection problem. I know it is not the same motor but I do not think that there is a wire in the harness that tells the injectors to fire. And, how do you know they are not firing because of an electrical issue?? Why not a fuel pump, fuel line, old fuel or tank issue. Cut the line and the tank out of the equation by hooking up a portable can straight to the engine using fresh gas. Give that a shot and see what happens. After that you will have to work upstream to the mechanical fuel pump (on the lower port side of the engine if it is the same as mine) etc. Give me your email address and I will shoot you a fuel/wiring diagram of a mercury EFI motor. May not be the same exact diagram but it will give you a general idea of the set-up.
09-07-2012, 12:41 PM
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Fuel injection is not a new invention. Even as early as the 1950s, various automobile manufacturers experimented with mechanical-type injection systems. There was even a vacuum tube equipped control unit offered for one system! This might have been the first "electronic fuel injection system."
Early problems with fuel injection revolved around the control components. The electronics were not very smart or reliable. These systems have steadily improved since. Today's fuel injection technology, responding to the need for better economy and emission control, has become amazingly reliable and efficient. Computerized engine management, the brain of fuel injection, continues to get more reliable and more precise.
Components needed for a basic computer-controlled system are as follows:
•A computer-controlled engine manager, which is normally called the Electronic Control Unit (or ECU), with a set of internal maps to follow. Changes to fuel and timing are based on input information matched to the map programs.
•A set of sensors or input devices to inform the ECU of engine performance parameters.
•A set of output devices, each controlled by the ECU, to modify fuel delivery and timing.
This list gets a little more complicated when you start to look at specific components. Some fuel injection systems may have twenty or more input devices. On many systems, output control can extend beyond fuel and timing. Most modern systems provide more than just the basic functions but are still straight forward in their layout.
There are several fuel injection delivery methods. Throttle body injection is relatively inexpensive and is used widely in stern drive applications. This is usually a low pressure system running at 15 PSI or less. Often an engine with a single carburetor was selected for throttle body injection. The carburetor was recast to hold a single injector and the original manifold was retained. Throttle body injection is not as precise or efficient as port injection.
Multi-port fuel injection is defined as one or more electrically activated fuel injectors for each cylinder. Multi-port injection generally operates at higher pressures (in excess of 35.5 PSI) than throttle body systems. At present, multi-port fuel injection is the only type used on outboards.
Port injectors can be triggered two ways. One system uses simultaneous injection. All injectors are triggered at once. The fuel "hangs around" until the pressure drop in the cylinder pulls the fuel into the combustion chamber.
The second type is more precise and follows the firing order of the engine. Each cylinder gets a squirt of fuel precisely when needed.
--------------------------------------------------------------------------------
Early problems with fuel injection revolved around the control components. The electronics were not very smart or reliable. These systems have steadily improved since. Today's fuel injection technology, responding to the need for better economy and emission control, has become amazingly reliable and efficient. Computerized engine management, the brain of fuel injection, continues to get more reliable and more precise.
Components needed for a basic computer-controlled system are as follows:
•A computer-controlled engine manager, which is normally called the Electronic Control Unit (or ECU), with a set of internal maps to follow. Changes to fuel and timing are based on input information matched to the map programs.
•A set of sensors or input devices to inform the ECU of engine performance parameters.
•A set of output devices, each controlled by the ECU, to modify fuel delivery and timing.
This list gets a little more complicated when you start to look at specific components. Some fuel injection systems may have twenty or more input devices. On many systems, output control can extend beyond fuel and timing. Most modern systems provide more than just the basic functions but are still straight forward in their layout.
There are several fuel injection delivery methods. Throttle body injection is relatively inexpensive and is used widely in stern drive applications. This is usually a low pressure system running at 15 PSI or less. Often an engine with a single carburetor was selected for throttle body injection. The carburetor was recast to hold a single injector and the original manifold was retained. Throttle body injection is not as precise or efficient as port injection.
Multi-port fuel injection is defined as one or more electrically activated fuel injectors for each cylinder. Multi-port injection generally operates at higher pressures (in excess of 35.5 PSI) than throttle body systems. At present, multi-port fuel injection is the only type used on outboards.
Port injectors can be triggered two ways. One system uses simultaneous injection. All injectors are triggered at once. The fuel "hangs around" until the pressure drop in the cylinder pulls the fuel into the combustion chamber.
The second type is more precise and follows the firing order of the engine. Each cylinder gets a squirt of fuel precisely when needed.
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09-07-2012, 01:07 PM
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Not sure about the old analog EFI's, but Port is right, on the newer stuff(3 litres), the harness from the boat is the same, the harness ON the motr is however different. My boatside harness for my 300x injection is the same harness I ran wwith my 2.4 carb 200.
09-10-2012, 11:19 AM
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lol gotta read all that still but did comp way before any of this its good, i know the injectors arent firing because i checked and theres only pwr to both wires at each inj an no ground, apply ground to one path an bam we got injection. trying to find out why theres no ground signal (pulse width for injection signal). ill read the rest of what you wrote now but wanted to let you know the first thing i do on any motor with issues is comp spark an fuel sample, check lwr units too cuz waters no bueno
09-10-2012, 11:34 AM
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Crap plan b, just did a bunch of lookin at vendors here there an cross sea's. Ebay, C/L an some google searches. No bueno. The issue i have with this current harness is at the throttle position sensor two of the color coded wires don't line up. You can visually see that the orange wire is going into the tan wire when the plugs come together, should i just cut the connector an splice together with heat shrink removable bullet connectors in case it doesn't work still? Im worried theres more issues with the harness an that why id rather have a good one. Also two other red wires i found taped together on top of pwr head..havent traced them to see where they went i noticed it when i was putting the cowling back on.
