2007 volvo penta 5.0 fuel injectors are not firing at all.

attowing@yahoo.com

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Ok I have spark and fuel pressure all the way to the injectors but they not pulsating at all. I have them all connected and raised the fuel rails to see and nothing come out as the not powering on. Whe. Tested injectors on rail with manually powering and the sprayed. Changed cam sensor, TPS. What else can shut down injectors besides ecu next? When injectors are in it would fire only when I'm pumping throttle. How is that when injectors are not working at all?? Thanks for reading20230428_135217.jpg
 

mvn

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Get your hands on Volvo service manual #7742218 (EFI diagnostics).
Diacom software or a Rinda Techmate scan tool will also help tremendously.

Mark
 

attowing@yahoo.com

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Get your hands on Volvo service manual #7742218 (EFI diagnostics).
Diacom software or a Rinda Techmate scan tool will also help tremendously.

Mark
Thank you. I'm gonna order one. I was hoping someone knew what can cause that.
 

Scott Danforth

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Could be as simple as a deteriorated battery not spinning the motor fas about that the ecm knows you are trying to start it, a bad ground or blown fuse, as moderate as mice damaged wiring or it could be as catastrophic as a bad ecm

Injectors run on a PWM signal by the ecm pulsing the ground

While waiting for the manual....

I would check all the wiring from the battery to the engine and then up to the helm

I would make sure the battery is up to snuff
 

Fun Times

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With the quote below, does the engine start and run normal when pumping the throttle?

When injectors are in it would fire only when I'm pumping throttle.
 

attowing@yahoo.com

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With the quote below, does the engine start and run normal when pumping the throttle?
Revs as long as you keep pumping. As soon as you stop it stops. But if injectors don't fire how does it start with me pumping fuel if it's fuel injected? Batteries atmre good and it cranks strong. Any specific wires I shout target ? Or any way to determine ecm is functional with out a scanner?
 

Fun Times

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If the engine runs at all no matter how it runs then the fuel injectors are indeed firing and the ECM is controlling the Injector pulse width hopefully at the correct timeframes and with enough proper flow which is most likely going to be okay.

It could either be flooding to much fuel or not enough air at the correct time’s making the engine die…or not enough fuel pressure may cause this type of problem too on some models.

With pumping the throttle could mean two things, one is your hitting the clear flood mode programmed within the ECM to shut off the fuel injectors at a certain throttle percentage or your bypassing the Idle air control valve and giving the engine the extra air it needs to start and run with throttle open then dies when closed due to no air.

Not saying these are your exact problems but something you need to know while diagnosing your symptoms.
 

attowing@yahoo.com

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If the engine runs at all no matter how it runs then the fuel injectors are indeed firing and the ECM is controlling the Injector pulse width hopefully at the correct timeframes and with enough proper flow which is most likely going to be okay.

It could either be flooding to much fuel or not enough air at the correct time’s making the engine die…or not enough fuel pressure may cause this type of problem too on some models.

With pumping the throttle could mean two things, one is your hitting the clear flood mode programmed within the ECM to shut off the fuel injectors at a certain throttle percentage or your bypassing the Idle air control valve and giving the engine the extra air it needs to start and run with throttle open then dies when closed due to no air.

Not saying these are your exact problems but something you need to know while diagnosing your symptoms.
But with injectors out of intake and on the rail they don't spray anything.
 

QBhoy

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Your injectors won’t spray anything at all unless the ecu tells them to, via a voltage applied to each. If your battery is anything less than excellent, there is intermittent, weak or no power supplied to the heavily electrical dependent ignition, sensory and fuelling systems. All because the act of cranking (healthy as it may seem) takes the vast majority of available power on tap, to do so. Can’t tell you how common a situation this is now becoming on engines like this and onwards in era.
If my mpi v8 has a less than perfect battery, it will crank fairly well but not try and fire any systems until the moment I let go of the key. For just that tiny moment, she will at best give a kick and a pop..if I’m lucky and quick enough, I’ve on a couple of occasions, been lucky enough to catch her on the throttle, with a quick blip of opening the throttle. Caught me out all those years ago and many since. Just with the old school assumptions that if she cranks, the battery must be fine and ruled out. Just simply not at all true on engines like this and all modern fuel injection ecu controlled units.
 

Fun Times

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Might want to try using a noid light tester at each of the wires to see if the injector circuit is working properly. I believe some auto parts stores will rent the noid lights at no cost such as Oreilles,

Though pricey at $100.00 this tool would help check the fuel injector pulse vibrations,

With the one photo supplied, the engine appears to be heavily rusted, have you removed and checked the ground wires that usually run from the ECM wire harness to the grounding studs/bolts to see if the wire crimp connectors are clean of corrosion and re-tightened for best installation.

There are fuses for the power side of the injector circuit, make sure the pin connectors are cleaned inside and try new fuses just to be sure.

Look up how to perform fuel injector balance test online.

Some Volvo engine models back around 2006ish had vibration issues with the fuse box mounted on the engine to where the engine would die or not start so I'll leave this here just in case, https://www.marinepartsexpress.com/... V01 Fuse Relay box replaced.pdf
 

attowing@yahoo.com

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Might want to try using a noid light tester at each of the wires to see if the injector circuit is working properly. I believe some auto parts stores will rent the noid lights at no cost such as Oreilles,

Though pricey at $100.00 this tool would help check the fuel injector pulse vibrations,

With the one photo supplied, the engine appears to be heavily rusted, have you removed and checked the ground wires that usually run from the ECM wire harness to the grounding studs/bolts to see if the wire crimp connectors are clean of corrosion and re-tightened for best installation.

There are fuses for the power side of the injector circuit, make sure the pin connectors are cleaned inside and try new fuses just to be sure.

Look up how to perform fuel injector balance test online.

Some Volvo engine models back around 2006ish had vibration issues with the fuse box mounted on the engine to where the engine would die or not start so I'll leave this here just in case, https://www.marinepartsexpress.com/VP_Service_Bulletins/209 PB P-37-2 N2 V01 Fuse Relay box replaced.pdf
Thank you. I checked all grounds. All are on so I'm gonna remove and clean all grounds on block to be sure. Can any other sensor shut down fuel injectors or ecu besides cam? Both pumps come on with key and it primes as it should.
 

QBhoy

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If cranking RPMs are below 200 it won't fire the injectors
Amen. So important to have a nothing but excellent battery. I literally just got back in from getting a guys 4.3 mpi running. He was for pulling apart all sorts of things. Engine turned over fairly well to the untrained ear. Had both batteries feeding the engine.
I found that one battery was all but finished and the other was less than healthy. Asked him to buy a new proper cca battery. Just that on its own feeding it…she fired first second or two of the key.
 

ripjmk

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Check the "crankshaft sensor" (under the crank pulley) unplug and clean the contacts, reconnect and try again. The camshaft sensor tells the ECU whitch stroke it is on (exhaust or compression) the crankshaft tells it the crank position for timing. If it is the same as the MEFI 4 ECU, not sure about the later ECUs.
 

attowing@yahoo.com

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Check the "crankshaft sensor" (under the crank pulley) unplug and clean the contacts, reconnect and try again. The camshaft sensor tells the ECU whitch stroke it is on (exhaust or compression) the crankshaft tells it the crank position for timing. If it is the same as the MEFI 4 ECU, not sure about the later ECUs.
That makes sense. I ordered the techmate pro s . But that comes in Wednesday. I will take it apart and clean tomorrow.
 

Dean0702

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That makes sense. I ordered the techmate pro s . But that comes in Wednesday. I will take it apart and clean tomorrow.
Have the same exact thing going on with mine right now!! Any chance you're going to see this and let me know what the solution was? Please please please😁
 

Scott Danforth

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Have the same exact thing going on with mine right now!! Any chance you're going to see this and let me know what the solution was? Please please please😁
Instead of hijacking an old thread, start your own
 
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