fuel pump relay
FJJ226
11-23-2007, 07:32 AM
how do you check if the fuel relay is good or not
old_master
11-23-2007, 07:50 AM
Year, make, model, and engine (8th character in the VIN) would be very helpful as the diagnosis procedures are not all the same.
FJJ226
11-23-2007, 08:09 AM
2000 chevy express 5.7 relay makes clicking sound is there another fuse before the fuel pump my pump is not running
old_master
11-23-2007, 08:16 AM
The fuel pump is fused before the relay. Current flows from the relay directly to the fuel pump. When the ignition switch is turned to the RUN position, the Powertrain Control Module (PCM) activates the fuel pump relay for approximately 2 to 3 seconds, and then deactivates the relay. This is commonly referred to as “fuel pump prime”. When the ignition switch is turned to the START position, the PCM activates the fuel pump relay continuously. When the ignition key is turned back to the RUN position, the PCM will keep the fuel pump relay activated provided the PCM is receiving a signal from the crankshaft position sensor indicating the engine is running. If the engine stalls, or is not running for any reason, the PCM will deactivate the fuel pump relay after approximately 2 to 3 seconds.
FJJ226
11-23-2007, 08:23 AM
so my fuel pump is bad basically when i turn my key on you can not hear the pump was curious if there is something else to check before i have to pull my tank
old_master
11-23-2007, 08:30 AM
Not necessarily. The connector at the fuel pump module must have power and ground for the pump to operate. If you take it a step further, from the connector on the pump module to the pump motor itself, there are more connections and wiring. Bottom line is that the pump motor itself must have power and ground. The connector at the fuel pump module is a known problem. Most new fuel pump modules come with a new connector that must be soldered on to the vehicle wiring harness. Check the connector at the fuel pump module for power and ground while the fuel pump relay is activated. Pump wire is grey, ground wire is black.
MT-2500
11-23-2007, 08:49 AM
so my fuel pump is bad basically when i turn my key on you can not hear the pump was curious if there is something else to check before i have to pull my tank
As Old master said you need to check for lose of power to fuel pump.
If fuel pump relay is working and putting 12 volts on gray wire to fuel pump work on back to the fuel tank wiring and plug in.
On the express van there is a fuel pump and gauge wiring plugin on crossmember between relay and fuel pump.
I have found a lot of problems at the plug in.
And on several I have had to rewire around the plug in.
Check for power to it and threw it to fuel pump.
MT
As Old master said you need to check for lose of power to fuel pump.
If fuel pump relay is working and putting 12 volts on gray wire to fuel pump work on back to the fuel tank wiring and plug in.
On the express van there is a fuel pump and gauge wiring plugin on crossmember between relay and fuel pump.
I have found a lot of problems at the plug in.
And on several I have had to rewire around the plug in.
Check for power to it and threw it to fuel pump.
MT
FJJ226
11-23-2007, 08:52 AM
where is the fuel pump module located at. first time to work on this vehicle since new fuel pump relay it only clicks tonce that is probably all it will do right
old_master
11-23-2007, 08:58 AM
Fuel pump module is in the fuel tank.
Garf
12-05-2007, 11:43 AM
My 1999 Express van refused to start after filling with fuel. Turned to be a bad fuel pump relay. Almost spent the weekend in Avon Park Fl.
Garf
12-05-2007, 11:52 AM
Exactly where is the fuel pump relay located on the 1999 Express 1500 4.3L? I was told it is under the dash, but that makes no sense. I also was told that the pump relay is energised from the oil pressure switch once the engine starts.
MT-2500
12-05-2007, 12:43 PM
Exactly where is the fuel pump relay located on the 1999 Express 1500 4.3L? I was told it is under the dash, but that makes no sense. I also was told that the pump relay is energised from the oil pressure switch once the engine starts.
I do not show a express van in 1999.
For more information on it start a new thread and someone will help you.
MT
I do not show a express van in 1999.
For more information on it start a new thread and someone will help you.
MT
Garf
12-05-2007, 01:49 PM
I do not show a express van in 1999.
For more information on it start a new thread and someone will help you.
MT
I will PM a pic of the manual showing the fact that it does exist.
For more information on it start a new thread and someone will help you.
MT
I will PM a pic of the manual showing the fact that it does exist.
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