I was driving down the street to work the morning after a typical Colorado
snow storm (6-10"). When I was driving on the highway the power went out and
it seemed like it ran out of gas. I had to pull out of traffic fast and try
and restart it. There was nothing but it turning over. It sputtered a few
times but never started up and ran for long.
Today we checked the fuel pump relay and it clicked when the key was turned
on. There was no fuel squirting out of the pressure valves on the fuel rail.
There was no noise coming from the fuel tank either. Could it be the fuel
pump? And is it better to install a inline fuel pump instead of replacing
the expensive in tank one?
I was looking at the MSD high pressure fuel pump part number 2225. Do I need
a regulator on it or does the truck all ready have one.
We want to steer away from the intake one since they don't work to well.
Thanks for any advice that you have.
Bad relay or bad pump. Jump the pump test line to power to test the
pump. If the pump comes on then the relay has burned contacts. If not
then it is probably the pump OR the connector for the pump.
Lets see 6 years of constant pumping and that's BAD???
A brand new Delphi pump module is 260 bucks.
The MSD pump is 120 or so and it will not work. First it doesn't create
enough pressure (40psi according to MSD, factory spec is 55-62psi MIN.)
Second you would need to pull the factory pump module, then rework it so
you have a working fuel gauge and fuel pick-up. It won't draw through
the factory pump because of the way the pump operates.
MUCH easier to simply unbolt the bed, slide it back onto a sawhorse or
two, clean off the tank, remove the pump module and replace it. While
your there you will want to replace the connector harness as well. They
are usually included with the new pumps. DIY should take about 4 hours
if you don't have to empty out the box first. If you have to empty the
box all bets are off....
This is MUCH easier than dropping the tank out the bottom unless you
don't have a choice. No working around the tank to disconnect the lines
or the fill pipes.
I had a friend replace a in tank one on his GMC jimmy and it died out with
in a few weeks and he had to drop the tank again. I would like to avoid that
whole mess and just fix it once. Then if it breaks again in 6 years then we
can do it again.
After further research on the pump the MSD pump didn't seem like a good
idea. I wish I could have read up on it sooner. But it looked like the right
one at the time.
And I think we are going to have to buy that pump without a return possible
now that they ordered one.
And I have replaced about 100 of them and had a total of ONE come back
(which was an aftermarket pump the owner supplied)
The common problem is that the people don't replace the connector
harness on the Blazer/Jimmy trucks. Then the pump burns up because of
the faulty contacts.
Use a factory pump and you won't have a problem. Use an aftermarket pump
and it becomes a crap shoot. That is why I posted the Rock Auto page.
You can get the same pump that the dealer will sell you for 4-500 for a
I would think you could return it easy enough. If not toss it on E-Bay
and get your money back.
When I replaced the fuel pump I used a pin extractor on the
connector to examine the crimps; the quality control standards
seem to have been followed since all the crimps were done properly
(no wire insulation found under the crimp section meant for just
the conductor). I've done this on radios that come with a wire
harness and I've found very crappy crimping.
Fortunately removing the fuel tank isn't a major job: it's just
annoying having to do it twice for the same job.
Desertphile's Desert Soliloquy. WARNING: view with plenty of water
I just replaced the pump in my 98 pickup. I bought a generic pump online
for $75. Dropped the tank. It was rather easier than I thought it would
be. The biggest problem was getting the lines disconnected. You need a
special tool, or a couple of really tiny flat blade screwdrivers to pop
the internal clips. Dropping the tank took about 20 minutes and can be
done on the ground with common hand tools. One strap. One bracket and
you need to disconnect the gas filler hose. Once the tank is on the
ground, you can break the lines free at the top of the pump as you will
not be reusing the old pump. Much easier to get the old lines free of
the plastic if you don't have the correct tool.
Once the tank is on the ground, it's a piece of cake to replace the
pump. Old one out. New one in. Aftermarket pumps require you to re-wire
a new connector on, but it's color coded and only means splicing 4 wires.
Note... drain the tank first.
Much easier to handle that way.
Steve makes a point about removing the bed, but on mine that would have
also required pulling off a fiberglass topper. I could see how it might
be easier to pull the bed.
Well we pulled the tank down and pulled the pump out and tried it again on
the outside of the tank in a cup of water. It worked and it shot the gas out
like a mad man. We are checking the fuel filter now. But I'm not sure if I
need to spend the money on a new pump. It could be the filter all along.
OK a couple of days ago it died again. And I don't think its something as
simple as a fuel filter. (since we already changed it again) I haven't ran
thru the diagnostics myself but I was wondering what I should check for to
see if the fuel pump is bad before dropping the tank.
I think that I am going to have to change the fuel pump. But I was hoping to
change just the pump instead of the whole module. I want to buy just the
pump and replace that. It seems like a waste of money to replace the whole
module since once I drop the tank its not that much more work to take apart
the pump housing and replace the pump itself. And cheaper.
Can you help me find a place online or even at a parts store like Autozone,
Checkers, Pepboys... but we are prepared to mail order too.
Not a surprise. That is why the original solution of replace the pump
was given. The pumps develop bad brushes or bad bearings, then moving
them around makes them appear to work, until they stop again.
Not possible to replace just the pump on the later units. Up until about
94 you replaced just the pump. Then they changed the pump design. After
that you replace the entire module. Which gives you a new pump, fuel
sock, fuel level sender and new wiring (which is frequently the cause of
pump failure when the contacts fail)
When you install the new module make sure you also replace the connector
on the end of the vehicle harness.
Its not impossible. In fact looks rather simple to pull out the pump itself
and slip a new one in. However, if spending the extra money is the best way
to go I guess that is what we will have to do. I don't want to mess with
What do you mean the connector? The wire harness itself or the plastic plug?
What do you mean? Thanks.
No not IMPOSSIBLE IF you can buy just the pump assembly, Which you
cannot. The earlier pumps don't fit in the later module housing. Now if
you had a 95-96 you could use a 94 pump and make it work.
That is why it becomes a not possible to do job. BTDT more than once.
I've changed out probably 100 of the pump modules.
When you pull the pump module there is a connector which plugs into it
on top. It carries power, ground and the level signal. The connectors
tend to be a problem. What happens is the pump starts to fail and this
causes it to draw more current. The higher current heats up the contacts
and causes them to lose some of their tension. This has the effect of
making a poor connection which increases the current draw more and makes
the problem worse. I have seen more than one where the actual plastic
shell was melted.
Most of the new modules come with a new connector assembly. You cut the
old one off, install the new pigtail with some GOOD sealed crimped
connectors and make sure they are secure. You will usually find that you
have to change it to keep the warrantee valid.
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