525efi fuel pressure bleeding off
#1
Registered
Thread Starter
525efi fuel pressure bleeding off
Took my boat to the mechanic this weekend and they did a fuel pressure test. (I was in there for routine drive maintenance so they did not have time to dig into it further). Trusted shop on LOTO. I have 1 motor lagging about 200 RPMs when cruising so they started with a fuel pressure test since they were pressed for time. When the key was turned on the pressure when to 43psi and held, as soon as key was turned off the pressure dropped to 0 with in a couple of seconds. Any thoughts? they are thinking possible injector or fuel pressure regulator. Where would you start?
#2
Registered
iTrader: (6)
Took my boat to the mechanic this weekend and they did a fuel pressure test. (I was in there for routine drive maintenance so they did not have time to dig into it further). Trusted shop on LOTO. I have 1 motor lagging about 200 RPMs when cruising so they started with a fuel pressure test since they were pressed for time. When the key was turned on the pressure when to 43psi and held, as soon as key was turned off the pressure dropped to 0 with in a couple of seconds. Any thoughts? they are thinking possible injector or fuel pressure regulator. Where would you start?
The following users liked this post:
therealmccoy (03-08-2021)
The following users liked this post:
speicher lane (03-08-2021)
#7
Registered
in order to bleed off 43PSI of fuel, it has to go somewhere.
The test was performed with a proper mechanical fuel pressure gauge correct?... or did someone make a dash mount 12v into a test gauge (battery supply goes off, reads 0psi even though the pressure is in system)
Probably grabbing at straws with that... but even a bad injector bleeding off that much could/should/would wet out a cylinder
The test was performed with a proper mechanical fuel pressure gauge correct?... or did someone make a dash mount 12v into a test gauge (battery supply goes off, reads 0psi even though the pressure is in system)
Probably grabbing at straws with that... but even a bad injector bleeding off that much could/should/would wet out a cylinder
Last edited by speicher lane; 03-08-2021 at 08:20 PM.
#8
Registered
in order to bleed off 43PSI of fuel, it has to go somewhere.
The test was performed with a proper mechanical fuel pressure gauge correct?... or did someone make a dash mount 12v into a test gauge (battery supply goes off, reads 0psi even though the pressure is in system)
Probably grabbing at straws with that... but even a bad injector bleeding off that much could/should/would wet out a cylinder
The test was performed with a proper mechanical fuel pressure gauge correct?... or did someone make a dash mount 12v into a test gauge (battery supply goes off, reads 0psi even though the pressure is in system)
Probably grabbing at straws with that... but even a bad injector bleeding off that much could/should/would wet out a cylinder
#9
Registered
Thread Starter
brand new mechanical snap on fuel gauge. I was standing there, It held pressure one time but the other 3-4 did not. we did not want to do it too many times and hydro lock the motor if it was an injector.
#10
Registered
iTrader: (1)
Voltage, applied to an injector or not, should not have anything to do with the injector loosing fuel. The ECM applies a ground to one leg of the injector to turn it ON (pulse). Removing 12V from one side without a ground being applied to the other side by the ECM should do nothing.
That said, turning power OFF does have an effect. So is it a bad injector issue of some sort, or an issue with the ECM. Keep in mind the fuel pump is not running
Is the correct method to test the ECM, injectors or other? Unsure if testing a MEFI-3 will be able to tell if it's applying a ground when power is removed for s split second before power leaves the injector.
Since RPM's were down from the beginning, I would lean toward testing the injectors
That said, turning power OFF does have an effect. So is it a bad injector issue of some sort, or an issue with the ECM. Keep in mind the fuel pump is not running
Is the correct method to test the ECM, injectors or other? Unsure if testing a MEFI-3 will be able to tell if it's applying a ground when power is removed for s split second before power leaves the injector.
Since RPM's were down from the beginning, I would lean toward testing the injectors