Fuel Pump don't hear running and engine won't start run
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Friday night at midnight I returned home from work in my trusty '95 SE. I parked in the driveway like usual. As usual, it wasn't driven for the remainder of the weekend until 46 hours later on Sunday night at 10 P.M. At that time, the first time since it was purchased new in Feb. '96, she wouldn't start.
She'* been perfect until now (91,000 miles later). Luckily, this happened while parked in the drive at home. What'* strange is the problem occurred while parked in my driveway between Friday and Sunday night. The first thing I checked was to make sure my gas tank wasn't siphoned. I poured about a gallon in the tank and the the gas meter reads about 3/4 full. Which is about what it read when I last drove it Friday night.
The starter turns strong and there'* plenty of cranking power from the battery. All of the electrical systems seem to be working correctly. Tacometer reads about 3-400 rpm while cranking.
When starting the engine I've always turned the ignition key clockwise and stopped at the "pre-ignition / electrical system on" position before turning the key fully clockwise to the run position to crank the engine. With the key in the "pre-ignition" position I'll wait for what I thought was the fuel pump running to inject fuel to the fuel injectors. Then after a second or two of the fuel pump running I'd turn the ignition key fully clockwise to the "run / cranking" position to start the engine.
But now I noticed I don't hear the "fuel pump" running when I turn the ignition key to the "pre-ignition / electrical system on" position.
I don't know much about this vehicles ignition and fuel systems. I've never had a need to service a problem like this before in the past. The 20amp fuel pump fuse looks good. It was loacted in the block above the insulator cover in the passenger (right) side foot well. I noticed a fuel pump relay plugged in the block. I pulled it and reinserted it to make sure it had a secure connection. I wonder if there'* a way to test the relay other than outright replacing it.
No system error codes are shown on the dashboard.
I checked the Schrader Valve on the front fuel rail. No fuel ejected when depressing the needle.
Based on this fact that there'* no fuel to the fuel rail I'm figuring the problem must be a defective fuel pump. Someone I was speaking with informed me that the gas tank must be dropped and the fuel pump removed from a port located on the top side of the tank. If this is correct it appears I'd have to drop the exhaust pipe from the converter back to the muffler. The exhaust pipe is located under the gas tank.
Is there any other suggestions / advice you could offer to verify it'* a defective pump before I embark on dropping the gas tank?
I thought about replacing the fuel filter. It'* never been replaced (91,000 miles). Where is it located?
Is there any electrical connections for power to the fuel pump that could be the problem?
Since the car is in the driveway I'd prefer to move it into the garage to perform any underbody work.
Thank you,
wzvhyz4gm
She'* been perfect until now (91,000 miles later). Luckily, this happened while parked in the drive at home. What'* strange is the problem occurred while parked in my driveway between Friday and Sunday night. The first thing I checked was to make sure my gas tank wasn't siphoned. I poured about a gallon in the tank and the the gas meter reads about 3/4 full. Which is about what it read when I last drove it Friday night.
The starter turns strong and there'* plenty of cranking power from the battery. All of the electrical systems seem to be working correctly. Tacometer reads about 3-400 rpm while cranking.
When starting the engine I've always turned the ignition key clockwise and stopped at the "pre-ignition / electrical system on" position before turning the key fully clockwise to the run position to crank the engine. With the key in the "pre-ignition" position I'll wait for what I thought was the fuel pump running to inject fuel to the fuel injectors. Then after a second or two of the fuel pump running I'd turn the ignition key fully clockwise to the "run / cranking" position to start the engine.
But now I noticed I don't hear the "fuel pump" running when I turn the ignition key to the "pre-ignition / electrical system on" position.
I don't know much about this vehicles ignition and fuel systems. I've never had a need to service a problem like this before in the past. The 20amp fuel pump fuse looks good. It was loacted in the block above the insulator cover in the passenger (right) side foot well. I noticed a fuel pump relay plugged in the block. I pulled it and reinserted it to make sure it had a secure connection. I wonder if there'* a way to test the relay other than outright replacing it.
No system error codes are shown on the dashboard.
I checked the Schrader Valve on the front fuel rail. No fuel ejected when depressing the needle.
Based on this fact that there'* no fuel to the fuel rail I'm figuring the problem must be a defective fuel pump. Someone I was speaking with informed me that the gas tank must be dropped and the fuel pump removed from a port located on the top side of the tank. If this is correct it appears I'd have to drop the exhaust pipe from the converter back to the muffler. The exhaust pipe is located under the gas tank.
Is there any other suggestions / advice you could offer to verify it'* a defective pump before I embark on dropping the gas tank?
I thought about replacing the fuel filter. It'* never been replaced (91,000 miles). Where is it located?
Is there any electrical connections for power to the fuel pump that could be the problem?
Since the car is in the driveway I'd prefer to move it into the garage to perform any underbody work.
Thank you,
wzvhyz4gm
#2
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Pretty much it sounds like you have a dead fuel pump. Even with a clogged filter, some fuel should still spray from the valve on the fuel rail. If you did find the fuel pump relay, switch it out with a new one or a known working one, if that doesn't solve it, it is most likely a dead fuel pump.
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With the key in the "pre-ignition" position I'll wait for what I thought was the fuel pump running to inject fuel to the fuel injectors.
I checked the Schrader Valve on the front fuel rail. No fuel ejected when depressing the needle.
Based on this fact that there'* no fuel to the fuel rail I'm figuring the problem must be a defective fuel pump.
#4
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Here'* a helpful link for you to read up on the fuel pump replacement.
'95-99 Fuel Pump Replacement
Note that some here have found that they were able to just unbolt the muffler and exhaust hangers and move them aside instead of removing them.
While I normally wouldn't suggest replacing something that'* not broken, in this case I normally would replace the fuel sender also while I am in there and have the tank dropped. It IS an extra expense, but is also a fairly common failure point for our cars. It'* your call on this and depends somewhat upon whether you have the extra funds to do so.
As to the fuel filter, yes, you should replace that, but I would wait until after the fuel pump change. That would ensure that you capture any loosened rust or scale that is dislodged during the pump change before you put the new filter on. I personally believe that fuel filters should be regularly changed. Some say every 15,000 miles and others use different frequencies, but they certainly should be changed no later than every 50,000 IMO.
'95-99 Fuel Pump Replacement
Note that some here have found that they were able to just unbolt the muffler and exhaust hangers and move them aside instead of removing them.
While I normally wouldn't suggest replacing something that'* not broken, in this case I normally would replace the fuel sender also while I am in there and have the tank dropped. It IS an extra expense, but is also a fairly common failure point for our cars. It'* your call on this and depends somewhat upon whether you have the extra funds to do so.
As to the fuel filter, yes, you should replace that, but I would wait until after the fuel pump change. That would ensure that you capture any loosened rust or scale that is dislodged during the pump change before you put the new filter on. I personally believe that fuel filters should be regularly changed. Some say every 15,000 miles and others use different frequencies, but they certainly should be changed no later than every 50,000 IMO.
#5
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Look behind your battery. You should find a black wire with a green connector on it.
Jumper 12V from the battery to this connector and listen for your pump.
After that, check resistance of that wire. It should have continuity to ground or open circuit depending on whether the ignition is on or off (should change state). This is your fuel pump relay changing state.
Don't jump into the tank until you verify fuses and relays are not the culprit. Please also edit your profile and put '95 SE' in your signature.
Jumper 12V from the battery to this connector and listen for your pump.
After that, check resistance of that wire. It should have continuity to ground or open circuit depending on whether the ignition is on or off (should change state). This is your fuel pump relay changing state.
Don't jump into the tank until you verify fuses and relays are not the culprit. Please also edit your profile and put '95 SE' in your signature.
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Originally Posted by willwren
Don't jump into the tank until you verify fuses and relays are not the culprit.
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I appreciate all of the prompt feedback.
I agree with willwren. Like most, I don't have much spare time, so the last thing I want to do is chase a problem without first diagnosing as many potential causes as possible.
I didn't mention this in my original post, but I also own an '02 SE. The '95 is Pure White and the '02 is Midnight Metallic Blue.
Willwren'* suggested to verify the fuel pump relay. I own a really good Fluke Multitester, but I struck another idea that may be easier to diagnosis whether the fuel relay is faulty or not.
I will pull the fuel pump relay and fuse from the '02 and plug it into the '95 that won't start and vice versa. I'll plug the relay and fuse from the '95 into the '02 to see if it'll still fire.
Then I'm going to double check if there'* fuel out of the schrader valve on the fuel rail while the engine is cranking.
If the fuel pump relay and fuse from the not running '95 operate correctly while plugged into the known running '02 then I'll have eliminated them as the cause of the problem.
Then I'll be right back to the potential causes being the pump.
Where is the fuel filter located? I'll need this information in the event I end up replacing the pump.
Someone metioned replacing the sending unit when replacing the pump. Could the sending unit alone be the cause of no fuel to the injectors?
Is there anyway to check if the crank and cam sensor may be the problem? I can use the sensors off of the '02 SE if they are easily removed and reinstalled. Where are these sensors located?
I agree with willwren. Like most, I don't have much spare time, so the last thing I want to do is chase a problem without first diagnosing as many potential causes as possible.
I didn't mention this in my original post, but I also own an '02 SE. The '95 is Pure White and the '02 is Midnight Metallic Blue.
Willwren'* suggested to verify the fuel pump relay. I own a really good Fluke Multitester, but I struck another idea that may be easier to diagnosis whether the fuel relay is faulty or not.
I will pull the fuel pump relay and fuse from the '02 and plug it into the '95 that won't start and vice versa. I'll plug the relay and fuse from the '95 into the '02 to see if it'll still fire.
Then I'm going to double check if there'* fuel out of the schrader valve on the fuel rail while the engine is cranking.
If the fuel pump relay and fuse from the not running '95 operate correctly while plugged into the known running '02 then I'll have eliminated them as the cause of the problem.
Then I'll be right back to the potential causes being the pump.
Where is the fuel filter located? I'll need this information in the event I end up replacing the pump.
Someone metioned replacing the sending unit when replacing the pump. Could the sending unit alone be the cause of no fuel to the injectors?
Is there anyway to check if the crank and cam sensor may be the problem? I can use the sensors off of the '02 SE if they are easily removed and reinstalled. Where are these sensors located?
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Your fuel pump relay and fuse are not compatible between your cars. They are totally different.
In addition, the pump and sending units are QUITE different. Your 95 does not require or suggest changing the sending unit with pump replacement.
The easiest troubleshooting method available to you is the one the factory built into your 95 (and not your 2002). The green connector behind your battery is for this purpose.
The filter is under the right side of the car just inside the right frame rail near the back tire.
You can't really test the cam and crank sensors with a meter. You can only shoot out the harnesses for them. The crank sensor is buried behind the harmonic balancer (crank pulley). It has to be pulled to gain access to it.
In addition, the pump and sending units are QUITE different. Your 95 does not require or suggest changing the sending unit with pump replacement.
The easiest troubleshooting method available to you is the one the factory built into your 95 (and not your 2002). The green connector behind your battery is for this purpose.
The filter is under the right side of the car just inside the right frame rail near the back tire.
You can't really test the cam and crank sensors with a meter. You can only shoot out the harnesses for them. The crank sensor is buried behind the harmonic balancer (crank pulley). It has to be pulled to gain access to it.
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I didn't see your reply before discovering the relay from the '02 is different. It'* a different GM part number. Also, the '95'* relay has 5 male blades. So, I couldn't plug it into the '02 fuse block that only accepted 4 blades.
Anyhow, with the insulator cover off from under the passenger side dash I was able to hear the relay switch on and off when turning the ignition key to turn on the fuel pump. This probably only confirms that the switch is switching, but it doesn't confirm the correct current.
I located the black wire with the green connector next to the battery. I will try your previous suggestion to check the operation of the relay.
I checked for fuel flow out of the schrader valve on my '02 SE. I did this just to check if I was checking it correctly on the "95. There was plenty of fuel spray with the spring loaded needle depressed and the engine cranking. So, i believe I've confirmed and double checked there'* no fuel flow to the fuel rail (schrader valve) when performing this test on the '95.
I'll keep you posted after I electrically test the fuel pump relay.
Thanks!
Anyhow, with the insulator cover off from under the passenger side dash I was able to hear the relay switch on and off when turning the ignition key to turn on the fuel pump. This probably only confirms that the switch is switching, but it doesn't confirm the correct current.
I located the black wire with the green connector next to the battery. I will try your previous suggestion to check the operation of the relay.
I checked for fuel flow out of the schrader valve on my '02 SE. I did this just to check if I was checking it correctly on the "95. There was plenty of fuel spray with the spring loaded needle depressed and the engine cranking. So, i believe I've confirmed and double checked there'* no fuel flow to the fuel rail (schrader valve) when performing this test on the '95.
I'll keep you posted after I electrically test the fuel pump relay.
Thanks!