Register or Log In To remove these advertisements. |
|
|
|
Thread Tools | Display Modes |
|
08-22-2017, 11:38 AM | #1 |
Registered User
Join Date: Jan 2015
Location: Big Rapids MI.
Posts: 98
|
One more question about disabling fuel pump
hello Guy's, In a previous post I asked about fuel pump relay location for disabling fuel pump for running a compression check. Now I am wondering if I can just take out the fuel pump fuse instead of relay? Thanks all.
|
08-22-2017, 12:05 PM | #2 |
Registered User
Join Date: Oct 2009
Location: .
Posts: 2,178
|
Re: One more question about disabling fuel pump
When doing a compression check, there is no need to do anything with the fuel pump circuit.
Take the keys out of the ignition and don't put them back in the ignition. You will not need them to do a compression test. Use a pedal depressor(or whatever you have, board/brick) to hold the throttle open. Use a jumper wire or a push button starter switch(specifically meant for compression checks) between the starter S terminal(purple wire) and the positive battery terminal. This way ensures the fuel pump will not run, the injectors will not pulse, and the ignition system will not fire. |
08-22-2017, 03:29 PM | #3 |
Registered User
Join Date: May 2004
Location: Minnesota
Posts: 4,620
|
Re: One more question about disabling fuel pump
Unplugging the fuse is better then unplugging the relay.
With the relay unplugged a redundant circuit that goes through the oil sender will supply power the fuel pump once the engine gets around 4 PSI of oil pressure. If you crank it long enough it should get enough pressure to make the pump run after some time. Unplugging the fuse stops power from getting to the fuel pump. This will most likely set a trouble code 54 in the computer. The code is easy to clear and will clear its self with time. Some people just unplug the injectors but if you do that be careful because the plastic may be very brittle and the tabs may break off. Disable the ignition also. The suggestion to use a push button starter switch for testing compression is the better method.
__________________
For those of you that are wondering why you are not getting replies to your thread: Did you give the model, year, engine, fuel system type, and transmission information? If it is modified from what came stock from the factory, let us know that too. |
08-22-2017, 11:42 PM | #4 | |
Registered User
Join Date: Jan 2015
Location: Big Rapids MI.
Posts: 98
|
Re: One more question about disabling fuel pump
Quote:
|
|
08-23-2017, 11:10 AM | #5 |
Registered User
Join Date: Oct 2009
Location: .
Posts: 2,178
|
Re: One more question about disabling fuel pump
When doing a compression test, the throttle needs to be open. It it's not, it will cause an air restriction, and give you false results.
|
08-23-2017, 06:34 PM | #6 |
Registered User
Join Date: Jan 2015
Location: Big Rapids MI.
Posts: 98
|
Re: One more question about disabling fuel pump
Thanks
|
Bookmarks |
|
|