1998 Blazer fuel pump stopped

I've viewed this forum often and gained valuable insite. Thanks to those that respond. I've searched and can't find a problem that is like mine, so here it is.

Drove my Blazer to work and then to lunch without any problems. When I was going to go home all systems seem to be working, starter, lights etc. The starter turned the engine without starting. After a couple of tries I noticed that the familiar buzzing from the fuel pump when you turn the key to "on" was missing. From noon until 4PM something broke while the car was sitting. Any thoughts?

I've viewed this forum often and gained valuable insite. Thanks to those that respond. I've searched and can't find a problem that is like mine, so here it is.

Drove my Blazer to work and then to lunch without any problems. When I was going to go home all systems seem to be working, starter, lights etc. The starter turned the engine without starting. After a couple of tries I noticed that the familiar buzzing from the fuel pump when you turn the key to "on" was missing. From noon until 4PM something broke while the car was sitting. Any thoughts?
Fuel pump relay on fire wall passenger. side between engine and heater box. Also Have some one turn the key while you use a meter to test circut at the fuel pump plug.Don't know if this will narrow it down for you but its a start. If you have juice back to the plg when the key is turned, I'd say the fuel pump if not try the relay.

One very common problem with electric fuel pumps falling all of a sudden
is, a dead spot on the armature of the pump motor. Some times you can
bump it and it will work again for a while. Until it shots on the dead spot again. Check the relay like family mechanic said. If the relay is working,check for voltage at the connector on the top of your tank. These fuel pumps aren't very cheap, so you want to make sure it is the fuel pump for sure. Check to see if you have fuel in the little valve fitting under your hood. Post back with the info please.
Thanks
SC

One very common problem with electric fuel pumps falling all of a sudden
is, a dead spot on the armature of the pump motor. Some times you can
bump it and it will work again for a while. Until it shots on the dead spot again. Check the relay like family mechanic said. If the relay is working,check for voltage at the connector on the top of your tank. These fuel pumps aren't very cheap, so you want to make sure it is the fuel pump for sure. Check to see if you have fuel in the little valve fitting under your hood. Post back with the info please.
Thanks
SC
Yea Like Southern Comfort said.Ther is a fuel pressure test port on the drivers side of the engine,at the back of the intake.You may have to move a few wires out of the way to see it. The valve will have a small cap on it almost like a tire valve stem.Remove it and check your fuel pressure there.On the fender well on the drivers side there will be a RED WIRE with a connector on it. The wire looks like it should be plugged into something,but it isnt.This wire is your test led for your fuel pump.You can run a jumper wire to this from the battery and it should make your pump cycle,and you should be able to atleast somewhat hear it.

Had same problem on my 98 blazer pulled into a store was running fine went out 15 minutes later wouldnt start tested pressure none from fuel pump be careful though chevrolet put 3 different fuel pumps in the 98
i took awhile to figure out but the difference is in where the seal is the rest of the pump looks the same
i replaced mine and it is working fine
good luck buy the way the pump is $300.00

Wow 300.00 mine was 84 bucks out the door. going rate in ohio.

prices are great in ohio dealer here wanted $600.00

Wow 300.00 mine was 84 bucks out the door. going rate in ohio.

Thanks for all the good advice. My schedule doesn't allow me to check it out before Saturday. Will let you know the outcome.
BTW, Fam_Mechanic, if I do need a fuel pump, where did you get the $84 dollar one? I checked around here (Cincinnati area) and it's in the $260 range.

Thanks for all the good advice. My schedule doesn't allow me to check it out before Saturday. Will let you know the outcome.
BTW, Fam_Mechanic, if I do need a fuel pump, where did you get the $84 dollar one? I checked around here (Cincinnati area) and it's in the $260 range.
goto http://www.autozone.com/servlet/UiBroker?UseCase=C001&UserAction=performSearch&Parameters=Auto+Store%7C%7EREGULAR+PARTS+LOOK+UP%7 C%7EFUEL+PUMP I'm sorry it was 90 bucks and I'm about 1.5 hours north of cincy in Springfield Ohio ,or about 15 miles do east of I70 & I75 crossing

Thanks for all the good advice. My schedule doesn't allow me to check it out before Saturday. Will let you know the outcome.
BTW, Fam_Mechanic, if I do need a fuel pump, where did you get the $84 dollar one? I checked around here (Cincinnati area) and it's in the $260 range. I cant believe its that much there.I only paid $277.00 for the whole pci unit and nut kit

prices are great in ohio dealer here wanted $600.00

The reason for the difference in prices is this,
1.)You can buy just the pump if you know the part number, from any GM dealer (~$100.00) you can look this up at www.gmpartsdirect.com
2.)You can buy the complete fuel pump assembly from most parts stores for ~$300.00. this includes the housing 2 strainer socks,and the float level sensor.
3.) you can buy this same assembly from any GM dealer for ~$450.00.

The best way to go (in my opinion) is to buy the assembly from Napa,Autozone, etc, because you get a new housing. The old housings have a tendency to crack or break during the retrofit, plus you get a new gasket.

I've viewed this forum often and gained valuable insite. Thanks to those that respond. I've searched and can't find a problem that is like mine, so here it is.

Drove my Blazer to work and then to lunch without any problems. When I was going to go home all systems seem to be working, starter, lights etc. The starter turned the engine without starting. After a couple of tries I noticed that the familiar buzzing from the fuel pump when you turn the key to "on" was missing. From noon until 4PM something broke while the car was sitting. Any thoughts?


First make sure that your battery is FULLY charged! Then attemp to start the vehicle using short bursts of the key (about 2 to 2.5 sec.). if after about 6 to 7 tries you hear the engine attempt top start, the your fuel pump is gone. I drove my ,96 arounf like that for a month. The short cranks allows the pump to build up enough pressure to allow the engine to start. This of coarse assume that there is still electrical continuity going through the pump and the volume is just not enough to start the vehicle.
Get a fuel gauge and check the pressure. That will of coarse answer your question.

The reason for the difference in prices is this,
1.)You can buy just the pump if you know the part number, from any GM dealer (~$100.00) you can look this up at www.gmpartsdirect.com (http://www.gmpartsdirect.com)
2.)You can buy the complete fuel pump assembly from most parts stores for ~$300.00. this includes the housing 2 strainer socks,and the float level sensor.
3.) you can buy this same assembly from any GM dealer for ~$450.00.

The best way to go (in my opinion) is to buy the assembly from Napa,Autozone, etc, because you get a new housing. The old housings have a tendency to crack or break during the retrofit, plus you get a new gasket.good way of getting to the bottom of that.One last note though,I have never needed to change the whole assembly.Once or twice I've had to cut the lines on top.They make a replacemet that have tapered ends so you can stick them down into the tube that u cut and solder or (swet) them together.Atleast they give you an option thank for finding out the price differance.I figured the assembly was a dealer part,so i never tried or have had to buy one (yet)

Had an opportunity to begin troubleshooting today.
1. Swapped relays in the under the hood fuse box - negative results.
2. Located a relay mounted on the passenger side firewall - Should I replace as a test? Is there a jumper test?
3. Can't find the red wire connector on the drivers side wheel well mentioned earlier. This one seems to be the definitive test. Hit it with a hot wire and see if the pump runs. If this is in error, is there another test lead?
4. Looked under the rear of the car and the leads to the fuel pump don't look accessible as well as being able to rap on the pump for a test. Did I overlook something?

I'm not opposed to dropping the fuel tank but don't want to unnecessarily.

Had an opportunity to begin troubleshooting today.
1. Swapped relays in the under the hood fuse box - negative results.
2. Located a relay mounted on the passenger side firewall - Should I replace as a test? Is there a jumper test?
3. Can't find the red wire connector on the drivers side wheel well mentioned earlier. This one seems to be the definitive test. Hit it with a hot wire and see if the pump runs. If this is in error, is there another test lead?
4. Looked under the rear of the car and the leads to the fuel pump don't look accessible as well as being able to rap on the pump for a test. Did I overlook something?

I'm not opposed to dropping the fuel tank but don't want to unnecessarily.

There should be three relays on the firewall. They're all interchangeable, so give it a try if you like, but the fuel pump relay is in the glove box (also three interchangeable relays there).
The red test lead for the fuel pump should be close to the firewall on the driver side fender wall. It will have a insulated fast-on (.250 wide) connector on the end. It should be sticking out of the harness bundle all by itself. (may appear to be orange)
edit;
The wire harness to the pump is on the top of the tank. You have to drop the tank to get at them (you also need a long arm). Be very carefull doing this, as the wire leads are short, and you need to support the tank as you lower it. It rather tricky getting at them without breaking plastic parts of the pump housing off. You can't rap on the pump because it's inside the tank.

good way of getting to the bottom of that.One last note though,I have never needed to change the whole assembly.Once or twice I've had to cut the lines on top.They make a replacemet that have tapered ends so you can stick them down into the tube that u cut and solder or (swet) them together.Atleast they give you an option thank for finding out the price differance.I figured the assembly was a dealer part,so i never tried or have had to buy one (yet)

I hope you're not soldering or sweating a line on gas lines. This is a disaster waiting to happen :lol2:

On these assemblies ('97 to '05) there's three lines, a feed (5/16"), a return (3/8"), and a vent. They are all plastic lines, and the feed and return lines have pinch connectors on them. The vent line is just a push-on pull-off flexible fitting. If you ever take these lines off the pump assembly, get new pinch connectors (I didn't, and had to drop the tank again to replace the leaking connectors- and I broke the plastic outlet on the pump assembly to boot- very expensive ).

No,No I solder the lines while the whole assembly was on the bench.I was also refering to the 95's

I had a similar situation and I couldn't figure out which pump I had before the parts place closed, so bought both(700 bucks later) and planned to return the other. I opened the boxes before I dropped the tank and one had a service bulletin in it that said the the '98 blazers (maybe others) had faulty electrical connectors on the end of the vehicle wiring harness. There is a$5.00 kit made that replaces this connector. If you notice that the plug on the top of the pump is worn, melted or full of dirt, you've solved the problem. I solved mine my wiggling the plug, and it worked! Then I opened up the plug, cleaned the terminals and put dielectric gel into the plug and TA-DA, the pump has run perfect since, without dropping the tank, without buying the kit, or replacing the pump and it only took about 10 minutes to fix. I would try this before even dropping the tank!!!
Apparently there is a TSB out on this and the shop people I've talked to at my local dealer they think it should have been recalled, but they're not making this cheap fix known to the public... Figures.

Something that I have not come accross in this thread yet is the fact that if the pump is loud enough while running, it is a good sign that the pump is going out...it may be tomarrow or a couple of years before it finaly goes but its well on its way...if your driving down the road and its been driving you nuts and your s10 dies, and you turn the key and dont hear it.....ill bet money that the pump is shot. This happened to me 2 weeks ago and now I love it.....no humm.....plus I did notice performance increase after I installed the new pump...also make sure that seal sits down into the tank....I have to drop my tank again and fix this.....it leaks when I fill her up...

Not to be picky but a humming form the fuel pump isn't 100% bad. When you turn the key on or off you should hear the pump prime with that wonderful sound. Not hearing it is a sign of being totally dead. I'll agree hearing it loudly while running isn't good but the pump on mine has whined since the factory, it made it about 90,000 (died w/o ANY warning) and the new one made a slight sound too(currently has 45,000mi on it).

Not to be picky but a humming form the fuel pump isn't 100% bad. When you turn the key on or off you should hear the pump prime with that wonderful sound. Not hearing it is a sign of being totally dead. I'll agree hearing it loudly while running isn't good but the pump on mine has whined since the factory, it made it about 90,000 (died w/o ANY warning) and the new one made a slight sound too(currently has 45,000mi on it).

I will agree with that...when you turn the key to the on possition you should hear a whine...but after it stops, THEN you start the vehicle....but when your driving down the road with the windows up and the radio at a clear hearing level and you can still hear the thing whining.....thats what Im talking about.....also I was told, by a GM mechanic that the pump runs hotter at 1\4tank or less becouse the pump is not all the way submerged in the gas to properley cool it. I also notice that my new pump is louder at 1\4 tank or less. This must be the reason. Im also told that these pumps are called low lubricating pumps. Boy Ill tell you....this setup sux.......but at 155000 miles I realy cant complain.

....but when your driving down the road with the windows up and the radio at a clear hearing level and you can still hear the thing whining.....thats what Im talking about.....also I was told, by a GM mechanic that the pump runs hotter at 1\4tank or less becouse the pump is not all the way submerged in the gas to properley cool it. setup sux.......

I've noticed that my aftermarket pump (Carter) is quite noisy-er than the original AC-Delco pump was. I can hear it over the radio, and I'm HARD of Hearing. But it works fine, and I kept my old pump in case of the Carter pump failing (I had to replace it because I broke a fitting of the case)

I've noticed that my aftermarket pump (Carter) is quite noisy-er than the original AC-Delco pump was. I can hear it over the radio, and I'm HARD of Hearing. But it works fine, and I kept my old pump in case of the Carter pump failing (I had to replace it because I broke a fitting of the case)
When I took my old pump out i was curiouse about the workings of the thing and I found that it had a carter pump inside the casing.....that may be why...so I am assuming this is the 3rd pump put in the truck?....I didnt notice if the new system I put in had a carter or ac-delco...but I can say that I can drive the truck and not hear it except when I first turn the key and the pump builds up pressure...and when the fuel gets below 1\4 tank.....so....if im looking forward to replacing the pump I put in at about anouther 75000 miles...I guess I need to find an external 60-66 psi pump....becouse the next time I do it iIm not spending 400 bucks....anyone know were I can find a 60-66 PSI external pump?

Yesterday was a really nice day so we tackled the fuel pump.

Removed the fuel pump from the tank and bench tested - dead.
Bought the new fuel pump, $270, and bench tested it before getting it "wet" - worked.
Reinstalled everything and going good.

The job took about 4 hours.

If anyone has any questions on problems we ran into etc, just let me know.

Thanks for all the good advice.

I've viewed this forum often and gained valuable insite. Thanks to those that respond. I've searched and can't find a problem that is like mine, so here it is.

Drove my Blazer to work and then to lunch without any problems. When I was going to go home all systems seem to be working, starter, lights etc. The starter turned the engine without starting. After a couple of tries I noticed that the familiar buzzing from the fuel pump when you turn the key to "on" was missing. From noon until 4PM something broke while the car was sitting. Any thoughts? check the ground wire on gas tank to frame they go bad fast grind frame clean drill hole and use nut and bolt to tighten down

I will agree with that...when you turn the key to the on possition you should hear a whine...but after it stops, THEN you start the vehicle....but when your driving down the road with the windows up and the radio at a clear hearing level and you can still hear the thing whining.....thats what Im talking about.....also I was told, by a GM mechanic that the pump runs hotter at 1\4tank or less becouse the pump is not all the way submerged in the gas to properley cool it. I also notice that my new pump is louder at 1\4 tank or less. This must be the reason. Im also told that these pumps are called low lubricating pumps. Boy Ill tell you....this setup sux.......but at 155000 miles I realy cant complain.

I agree that it shouldn't be screaming, but I guess it all depends on what pump you have, as someone later posted that their's is loud(which if it's that loud you should be scared). Anyway, I'd heard that info about the pumps heating up when low on gas, I wonder if that has anything to do with pump failure?

While I was at a dealer the other day I saw that they Guarantee the factory pumps for life... I didn't push the issue but maybe an option for replacement...?..

I also have a part number for the wiring harness on the fuel pump. I have an 18 gallon tank in a 4.3L 4Dr 4X4 but the Napa # is 888-543. The variations are: 888-544, or 888-553 depending upon your pump. It comes with new plug, about a 4inch wire lead, crimps and heat shrink. Not bad for 13.00 instead of the 351.00 pump.