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2000 Sonoma Replaced fuel pump ?????????

12-19-2010, 09:36 AM
Back in August I had to replace the fuel pump(it Died). I replaced it with an OEM replacement from Ebay - seller "SolidPro_auto_parts" Cost $184.00 1 yr warr.
Since then I have encountered a hitch in it performance occasionally. Every so often I needed to switch the relay(box under hood) with another relay and the pump would work?????(Stumped) A week ago I pulled in the driveway shut the truck off, never to start again. (p.s Frigid temps, no garage) I have replaced the relay with anew OEM relay. No start. Checked for continuity from the relay socket to the pump. Sometimes there is, sometimes there is not??? Not sure why? What this about an inertia switch?
Any help will be greatly appreciated.

12-19-2010, 04:53 PM
Clean all connections with CRC electronic cleaner and use dielectric grease to protect connections from the environment.

12-19-2010, 05:15 PM
2000 Sonoma, what engine?

There is no inertia switch on GM S & T series vehicles, never has been.

Checking fuel pressure and leakdown is the easiest and most reliable way to monitor fuel pump performance. Depending on what engine you have, the diagnostic procedures and specs are different. Do you have, or can you borrow a fuel pressure tester?

You mentioned that you installed an OEM fuel pump. Typically when someone refers to "OEM" for a GM vehicle, it means AC Delco or Delphi. They are the Original Equipment Manufacturers for GM but, when it comes to eBay, "OEM" usually means it's NOT AC Delco or Delphi. HUGE difference between OEM and "OEM style" fuel pumps. Gotta be REAL careful when buying from eBay. OEM pumps are usually good for 100,000 miles or more. "OEM style" pumps you can expect anywhere from zero miles to around 50,000 if you're lucky. If you have the 4.3L engine, the $184 price tag including shipping for AC Delco or Delphi is too good to be true.

12-21-2010, 10:46 AM
That may be true about OEM Vs Others. However I believe the price of $450-500 is outrageous for an OEM fuel-pump. What do they have in it $25-50. Heck my wife has been asking for a tennis bracelet for years. I can't afford it either. Otherwise why would I be driving a 10 yr. old truck.
I guess you get what you pay for. I'll grin and bear it for I will not pay that price. Time to switch to FORD or Kia.

12-21-2010, 10:48 AM
Thank You :)
I'll give it a try

12-21-2010, 04:46 PM
Check the fuel pressure and leakdown before you replace anything, it might be OK and something else is causing issues. Like you mentioned in your first post, continuity through the pump is erratic.... could just be a poor connection somewhere.

Chris Stewart
12-21-2010, 06:04 PM
And here's where you check it.

Fuel pressure test kits are available at most chain type auto parts stores. Harbor Freight has them for around $10.
62-65psi at idle is the spec isn't it OM?

12-21-2010, 06:15 PM
If it's a 4.3L: Key ON, engine OFF, fuel pump running: 60psi to 66psi and must remain above 55psi for 3 to 5 minutes after the pump shuts off.

12-22-2010, 10:42 AM
Thank you for the information.
Weather and time permitting I'll check what you suggest.

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