very hard start after sitting a day or overnight
#11
08-17-2014, 02:02 PM
thinking about coolant temp sensor, how can you tell if its working properly? would there be a code?
#12
08-19-2014, 09:25 PM
Not sure where the link in post #7 got their information, but don't trust it. Some of the specs are wrong, and some of the statements are totally incorrect.
Testing fuel pressure at the service port will tell you the maximum pressure that the pump can build, or regulated fuel pressure, whichever is lower. For example, if the pump can only build a maximum of 50psi, regulated pressure will be no higher than 50psi, no matter what the regulator is set for. For this reason, maximum pump output pressure and leakdown need be checked first, to make sure it can provide sufficient pressure, and hold it. All pressure and flow must end at the pressure tester, with no fuel allowed to the engine. The easiest place to do this is at the fuel filter outlet.
When you're certain the pump is good, (just cuz it's new, doesn't mean it's good) check regulated pressure and leakdown at the service port.
GM does not publish any "engine running" fuel pressure specs for these engines; zip, zilch, zero, nada. All tests are done with the engine off, not running or cranking, off. When the engine is off, manifold vacuum is zero. This causes the regulator to provide maximum regulated pressure for starting, when fuel demand is the highest. When manifold vacuum is present on the diaphragm in the regulator, regulated pressure drops because the demand for fuel is less.
Maximum fuel pump output pressure, with the pump running, must be 73psi to 108psi. Leakdown must remain above 55psi for at least 10 minutes after the pump shuts off. Regulated fuel pressure, with the pump running, must be 60psi to 66psi. Leakdown must remain above 55psi for at least 10 minutes after the pump shuts off.
Testing fuel pressure at the service port will tell you the maximum pressure that the pump can build, or regulated fuel pressure, whichever is lower. For example, if the pump can only build a maximum of 50psi, regulated pressure will be no higher than 50psi, no matter what the regulator is set for. For this reason, maximum pump output pressure and leakdown need be checked first, to make sure it can provide sufficient pressure, and hold it. All pressure and flow must end at the pressure tester, with no fuel allowed to the engine. The easiest place to do this is at the fuel filter outlet.
When you're certain the pump is good, (just cuz it's new, doesn't mean it's good) check regulated pressure and leakdown at the service port.
GM does not publish any "engine running" fuel pressure specs for these engines; zip, zilch, zero, nada. All tests are done with the engine off, not running or cranking, off. When the engine is off, manifold vacuum is zero. This causes the regulator to provide maximum regulated pressure for starting, when fuel demand is the highest. When manifold vacuum is present on the diaphragm in the regulator, regulated pressure drops because the demand for fuel is less.
Maximum fuel pump output pressure, with the pump running, must be 73psi to 108psi. Leakdown must remain above 55psi for at least 10 minutes after the pump shuts off. Regulated fuel pressure, with the pump running, must be 60psi to 66psi. Leakdown must remain above 55psi for at least 10 minutes after the pump shuts off.
Last edited by Captain Hook; 08-19-2014 at 09:31 PM.
#13
08-19-2014, 09:31 PM
Not sure where the link in post #7 got their information, but don't trust it. Some of the specs are wrong, and some of the statements are totally incorrect.
Testing fuel pressure at the service port will tell you the maximum pressure that the pump can build, or regulated fuel pressure, whichever is lower. For example, if the pump can only build a maximum of 50psi, regulated pressure will be no higher than 50psi, no matter what the regulator is set for. For this reason, maximum pump output pressure and leakdown need be checked first, to make sure it can provide sufficient pressure, and hold it. All pressure and flow must end at the pressure tester, with no fuel allowed to the engine. The easiest place to do this is at the fuel filter outlet.
When you're certain the pump is good, (just cuz it's new, doesn't mean it's good) check regulated pressure and leakdown at the service port.
GM does not publish any "engine running" fuel pressure specs for these engines; zip, zilch, zero, nada. All tests are done with the engine off, not running or cranking, off. When the engine is off, manifold vacuum is zero, and the regulator will provide maximum regulated pressure for starting, when fuel demand is the highest. When manifold vacuum is present on the diaphragm in the regulator, regulated pressure drops because the demand for fuel is less.
Maximum fuel pump output pressure, with the pump running, must be 73psi to 108psi. Leakdown must remain above 55psi for at least 10 minutes after the pump shuts off. Regulated fuel pressure, with the pump running, must be 60psi to 66psi. Leakdown must remain above 55psi for at least 10 minutes after the pump shuts off.
Testing fuel pressure at the service port will tell you the maximum pressure that the pump can build, or regulated fuel pressure, whichever is lower. For example, if the pump can only build a maximum of 50psi, regulated pressure will be no higher than 50psi, no matter what the regulator is set for. For this reason, maximum pump output pressure and leakdown need be checked first, to make sure it can provide sufficient pressure, and hold it. All pressure and flow must end at the pressure tester, with no fuel allowed to the engine. The easiest place to do this is at the fuel filter outlet.
When you're certain the pump is good, (just cuz it's new, doesn't mean it's good) check regulated pressure and leakdown at the service port.
GM does not publish any "engine running" fuel pressure specs for these engines; zip, zilch, zero, nada. All tests are done with the engine off, not running or cranking, off. When the engine is off, manifold vacuum is zero, and the regulator will provide maximum regulated pressure for starting, when fuel demand is the highest. When manifold vacuum is present on the diaphragm in the regulator, regulated pressure drops because the demand for fuel is less.
Maximum fuel pump output pressure, with the pump running, must be 73psi to 108psi. Leakdown must remain above 55psi for at least 10 minutes after the pump shuts off. Regulated fuel pressure, with the pump running, must be 60psi to 66psi. Leakdown must remain above 55psi for at least 10 minutes after the pump shuts off.
#14
08-19-2014, 09:58 PM
No schrader valve at the filter.
On your 2000, here is a parts list of what you'll need to make an adapter: 1997andNewerAdapterforcheckingFuelPump_zps5c876ad4 .jpg Photo by cwhook | Photobucket
Remove the quick connect fitting from the fuel filter, (leave the line disconnected). Connect the adapter to the fuel filter. Then connect your pressure tester to the adapter.
On your 2000, here is a parts list of what you'll need to make an adapter: 1997andNewerAdapterforcheckingFuelPump_zps5c876ad4 .jpg Photo by cwhook | Photobucket
Remove the quick connect fitting from the fuel filter, (leave the line disconnected). Connect the adapter to the fuel filter. Then connect your pressure tester to the adapter.
Last edited by Captain Hook; 08-19-2014 at 10:01 PM.
#15
08-19-2014, 10:29 PM
will have to order the supplies before my prime trial on amazon runs out haha
as for the fuel pressure tester, what do i need? one with a TBI adapter or something else? given the pump passes fine and the next step is to check the valve at the fuel rail
would this be sufficent for both applications?
as for the fuel pressure tester, what do i need? one with a TBI adapter or something else? given the pump passes fine and the next step is to check the valve at the fuel rail
would this be sufficent for both applications?
#16
08-20-2014, 02:13 PM
The Actron CP7838 only goes to 100psi, so the needle may go slightly past that, depending on your pump output. If both pressure and leakdown pass at the fuel filter, the pump is OK. If one or both fail, there is a problem in the tank. When you're certain the pump is OK, remove the adapter and reconnect the fuel line to the fuel filter. Next step is check pressure and leakdown at the service port by the distributor. If it fails one or both tests, the problem is in the plenum.
#17
08-20-2014, 05:00 PM
The Actron CP7838 only goes to 100psi, so the needle may go slightly past that, depending on your pump output. If both pressure and leakdown pass at the fuel filter, the pump is OK. If one or both fail, there is a problem in the tank. When you're certain the pump is OK, remove the adapter and reconnect the fuel line to the fuel filter. Next step is check pressure and leakdown at the service port by the distributor. If it fails one or both tests, the problem is in the plenum.
#18
08-20-2014, 05:33 PM
went to advanced...the guy physically showed me it last time and said it was 45. got a kid behind the desk saying its discontinued and it was 100 bucks....just got it on amazon. 41 bills and will be here friday so i got time to learn how to take the fuel filter off and get that down.
thank you for all your help captain! i will post results as soon as it gets done
thank you for all your help captain! i will post results as soon as it gets done
#19
08-20-2014, 06:37 PM
You don't need to remove the fuel filter, just the quick connect fitting. Release the retainer clip and slide the fitting straight off.
This will help you to release the clip: http://shop.advanceautoparts.com/p/a...fuel+line+tool
If you pick up a load of contaminated fuel, you can clog the filter in a matter of one block!
This will help you to release the clip: http://shop.advanceautoparts.com/p/a...fuel+line+tool
If you pick up a load of contaminated fuel, you can clog the filter in a matter of one block!
Last edited by Captain Hook; 08-20-2014 at 06:39 PM.
#20
08-20-2014, 07:24 PM
You don't need to remove the fuel filter, just the quick connect fitting. Release the retainer clip and slide the fitting straight off.
This will help you to release the clip: Autocraft 3/8" Fuel Line Filter Tool AC504/W83131: Get the best Engine Tools at Advance Auto Parts
If you pick up a load of contaminated fuel, you can clog the filter in a matter of one block!
This will help you to release the clip: Autocraft 3/8" Fuel Line Filter Tool AC504/W83131: Get the best Engine Tools at Advance Auto Parts
If you pick up a load of contaminated fuel, you can clog the filter in a matter of one block!