What is the best fuel pump?

After finally having the time to check fuel pressure in the wagon, I have none. Although I may be trying to broom the wagon in the spring, I always buy what I think are the best parts regardless of cost. I get almost everything from rock auto or amazon. They list fuel pumps from $18 to $100. And complete pumps with sending units up to $200. My fuel gauge is very in accurate but I am just planning on replacing the pump.

I am thinking about the Bosch pump. It is $53 and I have had great lucks with their other products.
anyone have any experience with them or other preferences?

Does the pump have power to it? Is it a pump failure or electrical problem? How many years/miles of service did the GM/Delco fuel pump give you? Any reason to change brands?

Rev Bob wrote:

Does the pump have power to it? Is it a pump failure or electrical problem? How many years/miles of service did the GM/Delco fuel pump give you? Any reason to change brands?

I have no idea if I am getting power out there or not. it has been somewhat of an intermittent problem.

IDK if it is an original pump or not. I have nothing against AC delco, but often times they no longer manufacture stuff. they sell a part someone else makes.

DO NOT BUY BOSCH!!!!

The best for the money is AC Delco or Delphi.

Fred Kiehl wrote:

DO NOT BUY BOSCH!!!!

The best for the money is AC Delco or Delphi.

please elaborate? I have bought their alternators and water pumps and been quite happy. I have mixed feelings about there plugs but I am a huge fan of NGK plugs.

As to the power to the pump issue, is there any easy way to test this?

back when I replaced the ICM and the coil, fuel would spray out of the Schrader valve from residual pressure.
after it died 2 miles later, now I have nothing. if there is something that tells the fuel pump to come on that I can check please let me know.

The car had 160K on it and is 23 years old. I don't mind throwing parts at it but I would like it to start and run.
more than anything I don't have time for it any more.

There is a harness plug with three wires that comes off the tank at the left rear corner.

You can use a car battery to test the pump while still in the tank. Black wire to Negative.

I'd have to check to recall which of the other two is for the positive lead to the pump. (Gray?)By putting 12 volts to the circuit, with jumper wires, you can hear the pump run.

The third wire is for the fuel gauge sensor.

Dave

I have had an excruciating experience with bosh pumps. I installed one, and 30 days later I installed the replacement...That one lasted a year and a half. I have a new Bosch pump that I will part with for $25 shipped.

Gray wire is fuel pump power lead (12V+), purple wire is sensor lead. You can unplug the 3-wire weatherpack under the left rear of the car near the tail light, and put power to the leads to check operation.

Buy the expensive EP376 pump. Usually regarded as being OEM quality and should last. Check ebay for NOS/parts lot selloffs, alot of stuff out there still from closed dealers and part stores. I scored a new in box AC Delco pump for my Caprice wagon for $20, for a $70+ pump

Delco hands down.

Bosch is junk. Went thru 3 of the damn things in my car. Which is surprising considering they're normally a reputable brand.

lakeffect wrote:

There is a harness plug with three wires that comes off the tank at the left rear corner.

You can use a car battery to test the pump while still in the tank. Black wire to Negative.

I'd have to check to recall which of the other two is for the positive lead to the pump. (Gray?)By putting 12 volts to the circuit, with jumper wires, you can hear the pump run.

The third wire is for the fuel gauge sensor.

Dave

THANKS DAVE!!!!

is this plug accessible with the tank in position?

Fred Kiehl wrote:

I have had an excruciating experience with bosh pumps. I installed one, and 30 days later I installed the replacement...That one lasted a year and a half. I have a new Bosch pump that I will part with for $25 shipped.

Well thanks, I will steer clear of them. like I said though I have had great luck with alternators and water pumps.

MalibuSSwagon wrote:

Gray wire is fuel pump power lead (12V+), purple wire is sensor lead. You can unplug the 3-wire weatherpack under the left rear of the car near the tail light, and put power to the leads to check operation.

Buy the expensive EP376 pump. Usually regarded as being OEM quality and should last. Check ebay for NOS/parts lot selloffs, alot of stuff out there still from closed dealers and part stores. I scored a new in box AC Delco pump for my Caprice wagon for $20, for a $70+ pump

THANKS!!! I will check to see if I get power (hopefully) and then put power to the pump.

Cadet57 wrote:

Delco hands down.

Bosch is junk. Went thru 3 of the damn things in my car. Which is surprising considering they're normally a reputable brand.

I guess Bosch just has a crappy supplier for that part. I agree most of the stuff they put there name on is good or at least has worked good for me.

I SUCK with automotive electrical. I would rather do just about anything than chase down an electrical problem. Unfortunately most everything now is so computer controlled you have to have an electrical engineering doctorate to work on a car.

I am considering getting a "power probe" I have seen this used on "Eric the car guy" videos and I think it would be handy. does anyone here have one and if so what do you think about it.

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The tank does not have to be dropped to get to the harness connector.  The whole purpose of using the connector is so you don't have to drop the tank to test it.

Actually the first step is even easier. Have have your wife or one of your kids turn the key to "key on" while you listen for the pump to come on. DON"T START THE CAR, just turn to the key on position.

All kidding aside, the easiest way is to stick your head down behind the drivers side rear tire when going to key on. You should be hearing the pump for a few seconds. It will not stay on, as the ECM is programmed to turn the pump back off if there is no signal seen from a turning distributor (or optispark)

IF you don't hear it, then either the pump itself or the wiring to the pump is bad. If you hear a sloshing sound, (like something is pissing in the tank) then there is a tear in the supply hose that   that goes from the top of the pump to the fitting on the cover. At that point you'll need get the tank out anyway. So might as well replace the pump while you are replacing the hose. No sense in having to pull it out again later when the pump does fail and you only replaced the hose.

The connection at the harness allows you to confirm that there is no issue with the" key on" signal coming from the dash. If it runs at the connector but not from key on, then there is a bad connection, or bad ground.  Chances are you'll hear sloshing or nothing.

Either way, I'd replace both pump and hose. How old is the pump? Original? Most times, you get a new hose with the pump kit. I personally don't trust the little plastic hose clamps that you usually get, and replace them with metal hose clamps instead.

I also don't trust the cheap rubber hose either, as it is not reinforced, Had one of them let go as well, So I get about a foot of reinforced fuel line hose that I can clamp to the pump and nipple on the underside of the cover. Just made a loop out of it. It will stuff into the tank just fine. Also make sure the gas filter sock at the bottom of the filter gets changed. Open the box, if their isn't one in the kit, get one while you are at the auto parts store..

One last thing, while you have the sender out, on the gauge rheostat, take a pencil eraser to the windings of the resistor and gently clean off the oxidation.


Dave

You can use a VOM. You are only checking for voltage between the gray and black wires at the pump. connect the battery to the relay bypass connector at the fuse block, and you will have a direct connection to the tank connector. If you get voltage, the pump, or the sender wiring to the pump is probably bad. You can also check for continuity of the wire without attaching the battery to the bypass, by measuring the ohms between the bypass connector and the gray pin of the connector. Check the black pin to the frame for continuity. It is usually the pump, but a friend of mine had a problem with the connector that passes through the sender plate. There is no way to check the connector without removing the tank.

Yes this is easy stuff and voltmeters are cheap. You can usually get a free one at harbor freight with a coupon. You don't need a fancy power tracing thingy to figure out if the pump is dead.

Some quick steps to determine the issue.

Connect 12V+ from the battery post to the bypass connector at the fuseblock under the hood with some scrap wire. It's a little black single pin connector with a red wire going into it. You should hear the pump run in the tank, get to the back of the car and listen. If nothing, silence then....

Step two, disconnect 3 pin connector under car below DS tail light. Connect voltmeter to car side of harness and turn to 0-20V DC setting. You should get voltage when keying on car. If you do not, then you have a bad relay,wiring issue, or PCM issue. If you do get voltage, run wires from battery posts directly to the gray (12V+) and black (ground) wires on the tank harness. Pump should run. If not, time to drop the tank and see whats going on in there.

I have had good luck with both the AC Delco and Spectra

I have a pretty decent digital multi meter. Along with at least half a dozen of the free HF ones. Unfortunately, about all I know how to do with any of them is check voltage or continuity. Did I mention I SUCK at automotive electrical…… (can wire a house no problem though)

FWIW I do not here the pump coming on from the engine compartment. I will have my child turn it on with me on the ground at the rear. Assuming I don’t hear anything I will disconnect the plug and test for voltage. If I do have voltage I think I can assume the pump is bad.

I bought the car with about 140K on it and it now has 160K if it is the original pump it is time to replace it. I would bet it is not the original pump since the fuel gauge is way off. Regardless it seems like the first step is to check for pump noise. Then the second step for voltage at the connector.

the power probe is just a convenient source of 12V power to test component function. Currently if I want to put 12V to something I have to rig something up with a battery charger.

frederickflintstone wrote:

I would bet it is not the original pump since the fuel gauge is way off.

The stock sender is notoriously inaccurate, and its accuracy degrades over time.

car was running ,. car quit,..

i doubt the wiring is degraded,. i doubt the ecm is bad,. i doubt the oil pressure switch is bad,.
I don't doubt the fuel pump kaffed,..

git er dun!

Likely so, but no harm in knowing how to check it BEFORE the tank gets pulled.

OK, I was able to have my son turn it on while. laying on the ground at the left rear. I herd nothing. it was dark out so no time to check for power at the plug. I will pull the plug and if I have power there I will order a Delco pump.

if I don't have power there, is there a separate fuse, fusible link, or relay to check?

Big THANKS to everyone who has replied. like I said previously I don't have a lot of time to work on this. All of your input really helps.

I finally just got under the car to test for power at the plug.
assuming I have the right plug.
I was not getting anything with a normal test light
I tried a LED test light and got power on the middle terminal. the power was constant though, it did not shut off after a few seconds.
I did not have my good multimeter but I put a harbor freight meter on it and it registered 5V with the ignition on.

so what is happening here?



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The 5 volts is the supply to the fuel level sender.

Rev Bob wrote:

The 5 volts is the supply to the fuel level sender.

THANKS?
does that mean I have no power going to the pump?  

if so is there a relay to check?

Did I mention that I am less than optimal at automotive electrical? (need a 240V plug in your shop for a welder? I am your man.)

There is a relay in the underhood relay center. It is driven by an output from the PCM. The relay is bypassed by a contact in the oil pressure switch. There is a red priming connection that will energize the pump just laying around next to the relay center. Putting 12 volts on the red connector will energize the fuel pump. However, this circuit is made through the NC contacts on the fuel pump relay, so the relay must be in place to use this connection.

This connection was used at the factory to prime the fuel system on a newly assembled car.

The relay can be checked by simply listening to it. When someone turns the key to ON, it should click in and hold for at least two seconds. During that time, there should be 12 volts on the fuel pump connector.

Rev Bob wrote:

There is a relay in the underhood relay center. It is driven by an output from the PCM. The relay is bypassed by a contact in the oil pressure sender. There is a red priming connection that will energize the pump just laying around next to the relay center. Putting 12 volts on the red connector will energize the fuel pump. However, this circuit is made through the NC contacts on the fuel pump relay, so the relay must be in place to use this connection.

This connection was used at the factory to prime the fuel system on a newly assembled car.

The relay can be checked by simply listening to it. When someone turns the key to ON, it should click in and hold for at least two seconds. During that time, there should be 12 volts on the fuel pump connector.

Thanks!!! I will investigate further.

Is this a follow up thread to your wagon suddenly crapping out on the highway? If so, congrats on finally finding what happened!!

TheRoadmasterKing wrote:

Is this a follow up thread to your wagon suddenly crapping out on the highway? If so, congrats on finally finding what happened!!

Yes, my wagon hasn't been on the road since late June. I cant say I have found the problem, but I am narrowing it down.
I am not currently getting power to the fuel pump



I have a few vehicles and a lot of responsibilities so the wagon has been on the back burner.

I bought my first corvette in April and most of my other toy cars have become superfluous. I did miss not having the wagon on our one summer road trip.

But it really looked bad that my wife was driving a POS and I was driving a vette (even if my vette is just a nice high mileage used car)

My wife's 09 Saturn had a premature transmission failure two years ago. I finally gave up on GM fixing the car even thought they covered the same problem on the larger trans. In July I bought a new $2000 transmission for it and spent the summer putting it in. I just got it on the road a few weeks ago and now am finding a little more time to fix the other vehicles.

OK I am getting really, relay confused.

I went to check the relay for the fuel pump. found out the 15A FP fuse was burnt. I put in a new fuse.
Tested the relay independently with 12V and heard it click. I went to test for power at the back and got nothing. (not even the 5V on the middle pin) For grins I plugged in the fuel pump and got nothing.

I checked the new fuse and it was burnt. put a new fuse in and watched it pop immediately. I disconnected the fuel pump, put a new fuse in and it did not pop. I did not here the relay click on but after a few seconds I heard it (or some relay) click. I have told it only stays on for a few seconds if there is no ignition.

having the fuse pop immediately with the FP hooked up would signal a bad or shorted out pump. what I don't get is why I didn't have power when I checked it after putting a fuse in???


I am getting perturbed with this.

Any more help would be appreciated.

power is only there for start up and if the ecm sees oil pressure,.
so you gotta be quick,.

Any other things so check? I am running out to church and to get a 9V battery for my good multi meter.

frederickflintstone wrote:

Any other things so check? I am running out to church and to get a 9V battery for my good multi meter.

Praying you get it figured out?

Andebe wrote:

frederickflintstone wrote:

Any other things so check? I am running out to church and to get a 9V battery for my good multi meter.

Praying you get it figured out?

Praying to the car gods no longer works. I used up all my good karma with prayers to get my wife’s Saturn back on the road. Most of the summer was spent putting a new transaxle in her car. I no longer get any joy fixing cars. I am happy that my wife now has a newer car that doesn’t look like a POS.
I am grateful that the problems with my jeep and corvette do not affect their ability to start stop and drive.

I am really disheartened with the wagon. The technology is such that they are much harder to diagnose than a 60’s muscle car but not as reliable as a 2000+ model year car. I just don’t have the patience and the knowledge to own an LT1 powered vehicle. With so many horror stories about the optispark I am glad to not have issues with that yet.

fuel pump ordered.

FWIW I finally got the fuel tank dropped this evening.
I get to put the new pump in tomorrow evening.
I hope this fixes the problem.

well I decided to do something productive with my insomnia and removed the old pump
To me this looks like an original OEM part.
I didn't see any supplier name on it just a 5 digit #

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since I have the tank down I am going to pick up some undercoating tomorrow and coat the metal.

it really is nice working on a southern car with no rust.

The tanks is back up and the fuel pump is in.
It will fire up for about 3 seconds then die.

It did this after I replaced the coil, but then the next time I went to start it, it ran. (until it died on the road test)

Hoping that tomorrow it will just run. I need to pull it out of the shop regardless.

I volunteered to help the cub scouts earn there fix it badge. I am teaching them how to change oil and chassis lube my jeep. along with rotating the tires..

No joy on it running. it will run for 3 seconds. is there a something I am missing? I pushed it out of the shop to teach the cub scouts how to change oil.

I would like to store it in a running state. I know this had dragged on all summer but I need to get my winter vehicle going. we actually got snow here on Wednesday

FWIW it started today. I ran it for about15 minutes then had the wife follow me for a 10 mile drive where I put some more fuel in it
will take it our for several more drives before I call it fixed.
other than hitting the schrader valve yesterday, and it not running then, I really don't know why it started now. After I put on the coil it did the same thing; would run for 3 seconds then die.

I really don't have any faith in it right now, but I hope it is fixed.

frederickflintstone wrote:

FWIW it started today. I ran it for about15 minutes then had the wife follow me for a 10 mile drive where I put some more fuel in it
will take it our for several more drives before I call it fixed.
other than hitting the schrader valve yesterday, and it not running then, I really don't know why it started now.  After I put on the coil it did the same thing; would run for 3 seconds then die.

I really don't have any faith in it right now, but I hope it is fixed.

Your wagon's problems have been quite a mystery but it's good that you got it running! Now let's hope it stays like that! I wish you the best of luck on your repair