Hello everyone,

The fuel pump in my 04'Monte Carlo started to blow fuse on start almost on any other start.
If it starts, everything is fine.
I changed fuel filter recently, so no issue there I guess.

May be the pump is going to die soon.

Is there a way to check it?

My next step is to get new pump. I am not in US and my option is only what is available by rockauto.

What is your opinion about Carter, Airtex and Delphi fuel pumps?
The price range is $170 to $280 excluding shipping

Thanks for your help,
Ivo

 

Hi Ivo.

Sorry to hear you Monte is sick, hope everything else is well in Bulgaria.

I would not be so fast to condemn the fuel pump. I would be more suspicious of a lose ground wire causing a short in the circuit. The fuel pump shares the same ground with other things like the starter , DRL's and possibly the heater blower motor. I know you've had electrical issues with your car so I would start with the wires. As you've described the fuse blowing when you start the car, I would first check a main ground located below the intake air duct. There is a stud bolt connecting the engine to the transmission with a large cable and two other small wires linked into one connector attached to that stud. Since the problem happens when you try to start, I'm thinking there may be a current spike from a high amp draw from the starter and fuel pump working simultaneously.

Here are a couple videos that might help. The author is an instructor and in my book is a highly respected auto electric diagnostics Guru.

The first video describes a blown fuel pump fuse in a Chevy Lumina. That video eventually shows the ground wire I'm referring to.
The second video described how to test the fuel pump. The fuel pump circuit of a Chevy Grand Prix with 3800 SC.

Hope this helps, keep us posted.

Good luck,
Curt

1. Blown Fuel Pump Fuse:
2. Fuel Pump Testing:

 

Hi Curt,

I did not describe the issue correct.

The fuse blows when pump prime the fuel system, not when the car starts.
That is why I suspect the pump. If it does not blow the fuse, everything is OK.
It happens from time to time, I cannot reproduce the problem by will.
I suspect pump is going bad, motor stops in some position and next time it tries to start it draws higher amps to start then designed, so fuse blows.

Thanks for the videos, really educating :-) I got to know electrics much :-)

 

Hi Ivo.
Just curious, were you able to find/fix the problem?

 

Hi Curt,
I do not have permanent solution till now as the problem is not persistent. (mad) I read on another forum that it could be bad relay and it is much cheaper fix to try before I change the fuel pump.
I ordered new relay and changed it yesterday. I will keep eye and ear to it :-)
I will keep updating :-)

Thanks,
Ivo

 

Thanks Ivo. Hope it is the cheaper fix.

 

OK, the tings went from bad to worst...

I will post picture of what I am talking about...

In short, fuse box under hood got burned around fuel pump fuse, thanks god, I expect problems and pulled over immediately I smell burned plastic...

As we say here... every bad comes to bring some good :-)

I found used fuse box on ebay with every fuse and relay in place, both big connectors and long portion of wire loom included. I will patch the wires there.

Next, I will drop the tank and see what is going on in there. I suspect it to be full of dirt because I got fuel filter clogged last year, actually the fuel pump problems started since.

Is there anything special I need to consider dropping the tank, besides disconnecting all wires and fuel lines?

I found on ebay just fuel pump kit, not the whole assembly which is much cheaper.
This one for example:
New AC Delco Fuel Pump Strainer with Installation Kit GM Vehicles ACD1001 | eBay

What I am concerned is the fuel flow. My car is whit L67 supercharged.
On rockauto they sell two types of Delphi fuel pumps. The one for non supercharged engine is with fuel flow rate 18g/s, the supercharger one is with fuel flow rate 27g/s.
Also, the system pressure is different, 360kPa vs 410kPa
See the links:
https://www.rockauto.com/en/moreinfo...538&cc=1424045
https://www.rockauto.com/en/moreinfo...567&cc=1424056
And of course, it is $100 more expensive.

Have any of you ever changed the fuel pump only?

Thanks for the help,
Ivo

 

Hi Ivo.
Sorry to hear about your bad luck, but it sounds like you have handle on it.

First of all, unless you're removing the fuel tank to clean it out, you don't need to remove the tank.
The fuel pump and strainer are accessed from the top of the tank through the access cover under the trunk carpet. Peel back the carpet below the rear speaker deck to expose the round access cover.
Secondly, you will need the fuel pump for the SC model with the higher flow rate and pressure.
Keep in mind you may need to replace the electrial connector with the new one that usually comes with the kit. GM redesigned the original connector because they had a problem with them coming unplugged.

There are several video tutorials on YouTube that demonstrate how to replace the fuel pump.

Good to here from, and good luck.

Curt

 

Here is the picture of what has happened :-(

 

Actually, the wire from relay, on the burned point, burnt its isolation on the back of the box.

I will take the pump out first, then drop the tank.

This is what came out of the fuel filter about one year ago:



What I am guessing is that the tank is dirty and some sludge is floating there. Before it happened, when I start the car in the morning, I clearly here the pump prime the engine. After some driving, it starts quieter and quieter until some time it blow fuse.

On the fuse box, what is the way to take wires out of it?
There is gray plastic clip on the back but it does not free them.


Thanks,
Ivo