How do I test fuel pump?

FWIW, I went thru similar situation with 94 Olds. I can tell you that after new pump installed, I could hear definite whine sound from filler pipe (BTW, dropping the tank is easy, it's getting it back up in place that's the pain )

Chief McGee wrote:

You should absolutely be able to hear the pump whining when you turn key on i t will however stop when pressure is reached. Not sure hwat your capabilitites are but i took an old fuel filter and cut off the threaded part that hooks to the fuel line. I brazed a nipple to this that i could hook on my Snap on fuel pump guage too. The also sell this adapter but i was to im patient ot wait for Snap on dealer. Before you do anything have you replaced you filter. Doyou live in a cold climate? Is it possible that the fuel line may be full of ice from water in the lines. Always ck the simple stuff first!

If you have a voltmeter or know one who has one. Check the voltage at the fuel pump connection. If you have a reading over 12 volts, it may be a relay problem or broken wire. Otherwise, since there is no whine it is probably the fuel pump. Make sure when you listen for the fuel pump you have someone turn the key for you and listen close to the tank. After the system pressurizes wihout starting the engine the pump will stop.

R> 1989 Chevy CK2500 350 V8 gas, manual, throttle body

My 93 s-10 blazer died on me ...at the local mall, snowing blowing and such. Crank but no sart. Called the 3 a's this guy comes over with a crow bar in his hand! I thought he was coming at me! He said he doesn't think he could put the Blazer on the flat bed, because his winch broke. he said, get in and start it when i say. He took the crow bar and gave the fuel tank a thud! Start her up!! I cranked it and it fired right up. Guy said the fuel puump is sticking..get it replaced! He whent back to he trruck and sad goonight, no charge! I replaced the pump the next day.. Andy

Hey Chief - Sorry I don't have the answer, but I have 2 points to get the flamers started. First, I don't hear the fuel pump on my 99 (10 more years of "technology") either. I read once that the fuel pump doesn't turn on until there is oil pressure so the engine would have to be cranking. I don't have a clue as to whether or not this is true. Second, I've changed 4 pumps in the tank and I've never had fun with it. To me, its a wrestling match and its amazing how much the damn tank fights back. So, I read that when doing a pickup, it just might be easier to lift the bed than to drop the tank. This might be true if you have a hoist and the stuff at the rear don't get in the way. BTW, I don't know anyone who's had to change the relay. That would be far too easy. Its the pump every time!

My 85 Year old UNCLE just Cut a Hole in the BED of The TRUCK.. Was A Simple Job to Change The fuel pump!!! made himself a Plate to put over the Hole

That sounds like a good idea too. I would consider it if I could pinpoint where the pump is under the bed. I would think that a foot square would be plenty of working room if you knew where the pump was exactly.

Yes that would be an easy way to replace the pump. But you could also take the two side bed bolts loosen the other side and just jack up the body. Been there and done that.

Alan

Thanks to everyone for the suggestions. I decided to cut a hole in the bed. Fairly easy to do, but took a larger hole then I expected so that I could get to the hoses. Picked this way in case I ever have to get in there again. Had it been a newer truck, I think lifting the bed is the way to go.

Now, I have another problem. With the pump out, and looking down into the tank, I can see a yellowish plastic tray floating at the bottom of the tank. Also found the "sender float" floating free in the tank. I guess that explains why the gas gauge has not worked in years. I assume the tray came loose and slooshed around, which knocked the float loose. Now what do I do with the tray? Can't get it out the pump hole. Can't leave it to float free and cause more damage. I assume it is a baffle to keep the gas from bouncing around. So, how and where does it attach to the tank? Tank is still half full so I will siphon out the rest and see if I can tell where it goes. Any suggestions?

Now that I think about it, when I am low on gas the engine would die when stopping the truck. I assumed this was from the gas shifting forward. It would start right back up and run fine on level ground. So, I'm guessing that this tray is a baffle system to keep gas around the pump during a stop. Thanks, Chief

New fuel tank from that horrible place, AutoZone is $149. Whitelightning

That's an option for sure, you can go to a junk yard and buy a used 14-18 year old gas tank.

Whitelighting