Fuel injector stuck closed

[mcgradypilot]

Hey guys/gals. I have a 1993 Four Winns with a Volvo Penta 5.7 GLi PLKDCE Duoprop drive. GM 5.7 with TBI. I just purchased it and have been slowly fixing various issues. My current dilemma is that both fuel injectors are stuck closed. Has anyone here ever had this problem? I am thinking of removing them and GENTLY trying to coax them to move. Both fuel pumps where locked and I managed to coax the low pressure into working. Any ideas would be helpful. Also, are the injectors interchangeable with standard chevy injectors? Im thinking a trip to the you-pull-it could quickly solve this.

 

[Mr. Asa]

Re: Fuel injector stuck closed

I would think that they'd be interchangeable, but the key point would be finding the proper size and compatibility.

From my experience, the only time injectors get stuck is when they have a wiring issue.

You should be able to test the injector itself to ensure it's stuck with just a 9v battery (you don't really want anything higher because injectors are fairly delicate and the full power of a 12v automotive or marine battery can damage the coils in an injector).
Should be able to remove the harness, then using some alligator clips you can complete the circuit of the injector and battery and you should hear a little "click"
If you're hearing that click, then you've got an issue with a signal getting to the injectors, if you're not hearing that click you have an issue internal to the injector.

Sometimes, tapping the body of the injector with a very small hammer while having someone else try to get the injector to "click" with the battery can loosen everything enough to get it to start cycling again.

 

[mcgradypilot]

Re: Fuel injector stuck closed

I tried the 9v test and got nothing. Ill post some pics in the morning. I was worried the ECU was toast because my multimeter wouldnt show the voltage rise every time time circuit closed. Then realizing the pulse is most likely too quick for my meter to read I tried a test light and got good solid flashes. Ill post pics in the morning of what I find. Thanks.

 

[Mr. Asa]

Re: Fuel injector stuck closed

Yeah, you'd definitely need to have some sort of recording device to see if the injectors are receiving signal.

I've used that test on more modern injectors and had it work, but the TBI might be slightly different as they are some hefty suckers. I am not a Chevy guy, so I'm not as familiar with them and what they use to signal, but they might be strong enough to need to take full battery voltage. However, I wouldn't do that until I checked the tech specs to see what the injectors could take.

You might be able to use some other engine sensors to test if the ECU is working.
Do these things have trouble codes like an automotive engine?