Could this be a fuel pump problem?

[RottenRalph]

I'm crusing along fat and happy on the Interstate at 68MPH getting 8.2 MPG per the computer. I had been driving for 65 miles. I have 1/2 tank of gas. It's 95 F outside, I'm by myself so I'm using the dash air only. In about a 10 mile stretch of flat hwy I went from 8.2 MPG to 6.5 with no good reason. 2 miles before my off ramp I had to make a pass using the accelerator. Thats when the engine missed but kept going. After exiting and coming to a stop the engine died while waiting for a traffic light. Started right back then sputtered a little until I reached my home about 7 miles away. It died again when I pulled in the drive. Started back until I parked. The fuel pump whines a little more than usuall but I'm thinking that because I have 1/2 a tank when I normally keep it full. Would anyone help I.D. this problem?

Thanks

[oemtech]

Check the fuel rail pressure... should be 55 to 62 psi. Then change the the fuel filter.

[DriVer]

This could be a throttle control module problem OR as Oemy suggested a plugged fuel filter. Unless you can measure the fuel rail pressure this would be a task best left for a guy like Oemy to do.

The filter for your vehicle is cheap so get a good one. NAPA makes a good filter for your 2003 application. Bring the old filter with you if you do not know the number. It is listed in the Owner's Manual and the Chassis Guide.

Oemy also lists the numbers on his website.

[RottenRalph]

Asking for more guidance, here's what's going on. Purchased a NAPA Gold filter and borrowed a pressure gauge from Auto Zone. Obtained pressure readings of 46 PSI with key on and 49 PSI w/ engine running (I wouldn't know why it would be different). Changed the filter and still have the same pressure readings.

Is this enough info to say the pump is bad?


Thanks again!

On edit. If Dale's garage was close to me I wouldn't be asking for this help. It would already be there. My local WH service center is well behind in service and the times. They may have gotten better since my last visit. I have a trusted local mechanic but he has missed codes (ABS)on his Snap on scanner. I'm affraid he may have the same type of problem if I go to him for this.

[oemtech]

From what I know the fuel pump puts out about 90 psi and the fuel rail regulator drops that to 55 to 62 psi. I would test the output of the pump...

[RottenRalph]

My local mechanic now has this job. He ask if I could pick up a fuel pump for him.

Dale, I looked on your website for a PN but didn't see it. Can you provide this #?. While the tank is dropped, what else needs to be changed?
Thanks again.

[mike brez]

I have had to drop my tank a few times due to a rusted tank. I wish i would have cut a hole in the floor under my bed for access to the fuel pump.

[RottenRalph]

It was a bad pump helped by sandy black stuff in the tank. I'm still a little confused because the rail pressure goes straight to 65 PSI for about 1 second then drops to about 50. Is this the norm?

Mike Brez

After seeing the sock filter on the pump's pick up tube and the grit in the bottom of the tank, I think cutting a hole in the floor would be pointless. Seems if the pump goes bad you should always drain and clean the tank or face the same issue sooner than later.

[DriVer]

Quote:

Originally Posted by RottenRalph Seems if the pump goes bad you should always drain and clean the tank or face the same issue sooner than later.

RottenRalph, If something is worth doing ...... etc!

[oemtech]

I suspect that the initial pressure of the pump (90 psi) and the regulator on the fuel rail set the pressure to 65 psi. But, do to the dirt, plugged fuel filter, bad pump etc the pressure can't be maintained.

[oemtech]

Listen up folks.....

Got a call from a fellow RVer with 94 Fleetwood Flair with a bad fuel pump. I cross xref'd the part number (25028274) he gave me and could not find a replacement other than GM/Workhorse. Needless to say it cost him $400 for the pump, $100 next day air and $300 labor to R&R. He is in Yellowstone, I think, and the pump was at a GM dealer in FL. Now it gets really bad.... it did not fix the problem and the service folks are telling him it needs to go do the road to another shop for repair (tow at his expense) as they do not know what is wrong.

In tank pumps "SUCK".. pun intended!

[EngineerMike]

Dale- I had a Ford pickup w/2 tanks & a pump in both. By 160,000 I had replaced one pump twice, and the other one once. Now get this- they were different parts! And $100 difference in price!!! In tank pumps are an excuse to charge stupid high prices for proprietary parts.

So, the question- Is it time for Oemy's pump kit? New solder-in dip tube & converter kit?

[mike brez]

I purchased my fuel pump from my local Car Quest auto supply. i think it was like $100.00

[oemtech]

Is this the same pump used in the W series # 25028274.

Post the part number anyway.