Why is my 88 tbi eating fuel pumps??? 3 in the last 18 months 10k miles? 2 were parts store junk the last a ac Delco? New filters every time? I don't understand why they keep dying? I keep at least a 1/2 tank of gas or more in it. It's not contamination ? I run a adjustable fuel pressure regulator and 15 psi using a tpi pump this last time. Could low voltage or bad ground be causing it?
CK5
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fuel pump again!
- Thread starter prolinews
- Start date
Did you test these things when you pull them to ensure the pump was bad?
rampage
3/4 ton status
Disconnect the fuel line at the filter and connect a hose to it (into a suitable container of course!). Then jumper the fuel pump relay under the hood to make the pump run. Presto, empty tank.
Yes, but is that out of the vehicle, or on?
I know aftermarket is junk, and AC Delco is heading there with everything of theirs coming from China now too, but three in less than 15 years would have me pissed.
I know aftermarket is junk, and AC Delco is heading there with everything of theirs coming from China now too, but three in less than 15 years would have me pissed.
My friend replaced more than one fuel pump in a few GM car & trucks,and later discovered it wasn't the fuel pumps dying,it was a multitude of other things causing the pumps to "fail"..
In one car,a late 90's Buick,that had 3 new fuel pumps installed in a years time,turned out to have badly corroded ground wires behind the passenger side kick panel,where a buss bar with several grounds for the ECM and other devices,were all gangrene--he cleaned all the wire connections off with a dremel and wire wheel,and the car started right up,the fuel pump was not "bad",it just was not getting sufficient voltage..the car would run great sometimes,then start stalling out after a ride lasting more than several minutes,then after sitting,it sometimes would fire right up again,and not act up for quite some time..other times it simply refused to run,until it sat a day or more...the ground must have been heating up and breaking connection..
He stopped using a LED test lamp to test for power at the fuel pump connector,because they do not put enough load on the wiring to indicate if the voltage was low--an LED lights up bright even if it only gets a few volts,giving a false indication the wiring is delivering a full 12V at the proper amperage..--when he decided to use his old reliable test lamp with a real bulb,he saw it only glowed like it was getting a few volts..
He ended up following the wire back to the fuse box and saw it was getting full voltage there,so evidently the wire was bad somewhere along its run to the pump--he cut it off,and spliced a new 12 ga wire right to the fuel pump connector (which was new,and often comes with a new pump,since they are noted for having poor connections after years of use and salt getting in them)...that "fixed" the truck,without having to drop the tank again..
He has also had a few vehicles that had the ECM failing to activate the fuel pump reliably...a used one from a junkyard confirmed it wasn't the fuel pump dying,it simply wasn't being turned on by the ECM..Fuel pump relays can act weird too,he usually swaps one of the other relays in the fuse box to the fuel pump slot to see if that changes anything before doing further diagnosis..
In one car,a late 90's Buick,that had 3 new fuel pumps installed in a years time,turned out to have badly corroded ground wires behind the passenger side kick panel,where a buss bar with several grounds for the ECM and other devices,were all gangrene--he cleaned all the wire connections off with a dremel and wire wheel,and the car started right up,the fuel pump was not "bad",it just was not getting sufficient voltage..the car would run great sometimes,then start stalling out after a ride lasting more than several minutes,then after sitting,it sometimes would fire right up again,and not act up for quite some time..other times it simply refused to run,until it sat a day or more...the ground must have been heating up and breaking connection..
He stopped using a LED test lamp to test for power at the fuel pump connector,because they do not put enough load on the wiring to indicate if the voltage was low--an LED lights up bright even if it only gets a few volts,giving a false indication the wiring is delivering a full 12V at the proper amperage..--when he decided to use his old reliable test lamp with a real bulb,he saw it only glowed like it was getting a few volts..
He ended up following the wire back to the fuse box and saw it was getting full voltage there,so evidently the wire was bad somewhere along its run to the pump--he cut it off,and spliced a new 12 ga wire right to the fuel pump connector (which was new,and often comes with a new pump,since they are noted for having poor connections after years of use and salt getting in them)...that "fixed" the truck,without having to drop the tank again..
He has also had a few vehicles that had the ECM failing to activate the fuel pump reliably...a used one from a junkyard confirmed it wasn't the fuel pump dying,it simply wasn't being turned on by the ECM..Fuel pump relays can act weird too,he usually swaps one of the other relays in the fuse box to the fuel pump slot to see if that changes anything before doing further diagnosis..
hidesertwheelin
1/2 ton status
Take your angle grider with a cutting wheel, cut hole in floor above fuel tank, remove fuel pump. Go to pick n pull with 18v sawzall, cut out patch panel an inch or two bigger on each side than the hole you cut, and attach with self tapping screws! Hole is now covered, and you have a easy access to the fuel pump
crazedyak
That Guy
http://coloradok5.com/forums/showpost.php?p=3009987&postcount=6
Old post of mine from many moons ago.
Old post of mine from many moons ago.
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I guess it's fixed? I changed the fuel pump relay put a new optima red top , new filter cleaned a couple grounds. I'm not sure if it is fixed or a intermittent issue? Fuel pressure back to normal not sure what was going on with it. I was driving off road when it went down I looked for chafed wires and couldn't find any. I don't know if was a combination of factors or if the relay was going bad? I did check the voltage at the pump and it was the same as at the battery while running.
